BOOKS OF RtfiDIfGS - PAHO/WHO
BOOKS OF RtfiDIfGS - PAHO/WHO
BOOKS OF RtfiDIfGS - PAHO/WHO
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MASTER COPY - NO TOCAR<br />
<strong>BOOKS</strong> <strong>OF</strong> <strong>RtfiDIfGS</strong><br />
Serie Desarrollo de Recursos Humanos No. 50<br />
fDUCRTIOf Of OPERATIOllAL RESERRCH<br />
.AnD SYSTfm AnALYSIS If HERLTH<br />
SERVICES RDmliNlSTRRTIOI n PROGRARS<br />
PROGRAM <strong>OF</strong> EDUCATION IN HEALTH ADMINISTRATION<br />
DIVISION <strong>OF</strong> HUMAN RESOURCES & RESEARCH<br />
PAN AMERICAN HEALTH ORGANIZATION<br />
WORLD HEALTH ORGANIZATION<br />
J
CONTENTS<br />
OPERATIONAL RESEARCH & SYSTEM ANALYSIS<br />
Paqe No.<br />
INTRODUCTION .. .............................. ........ i<br />
FINAL REPORT ....... ....................<br />
List cf Articles<br />
Fetter, R.B., Y.Shin y cols. - Case Mix definition by 34<br />
diagnosis-related groups. Medical Care (l8)2 Supplement<br />
1-52, 1980<br />
Frerichs, R. y J. Prawda. - A Computer simulZation model 90<br />
for the control of rabies in an urban area of Colombia<br />
Management Science 22(4)1.41-421, 1975.<br />
Greenland, S., E. Watson y R. Neutra. - "The Case Control 101<br />
method in medical care evaluation. Med. Care 19(8),August<br />
1981.<br />
Lev, B., G. Revesz y cols. Patient flow analysis and the 108<br />
delivery of radiology service. Socio-Econ. Plan Sci 10.<br />
159-166, 1976.<br />
Meredith, J. Program evaluation techniques in the heaZth 116<br />
services. Am J. Public HeaZth 66(11): 1069-1073, 1976<br />
Nutting, P., G. Shorr y B. Burkhalter. Assessing the 121<br />
performance of medical care systems: A method and its<br />
application. Med. Care 19(3), March, 1981<br />
Reis,,,n,, A., J. Mello da Silva y J.B. Mantell. Systems and 137<br />
procedures of patient and information flow. Hosp Health<br />
Serv. Admin. Winter: 42-71, 1978<br />
Shuman, L.J., H Wolfe y R. Dixon Speas, Jr. "The role of 167<br />
operations research in regional health planning. Operations<br />
Research 22:234-248, 1974<br />
Vraciu, R. "Programming, budgeting, and control in health 181<br />
care organizations: the state of the art. Health Serv. Res<br />
14(2), Summer, 1979<br />
Duran, L. y A. Reisman. "Design of alternative provider 205<br />
team configurations: experience in both developed and<br />
developing countries. Technical memo 947, Department of<br />
Operations Research, Case Western Reserve University3<br />
Cleveland, Ohio, 1980
- ii -<br />
liancock, W., D. Magerlein y cola. - "Parametera affecting 229<br />
hospital occupancy and implications for facility sizing<br />
HeaZth Serv. Res 13(3), Pall. 1978.<br />
Hindl, A., N. Dierckman y cols. - "Estimating the need 243<br />
for additional primary care plzysicians. Health Serv. Res<br />
13(3), Fall, 1973<br />
Reisman, A., B. V. - Dean y cols. '"Physician supply and 255<br />
aurgical demand forecasting: a regional manpower study.<br />
Management Science 19(12): 1345-1354, 1973.<br />
Abernathy, W.J. y J. C. Herahey. "A Spatial allocation 268<br />
modeZ for regional health services planning. Operations<br />
Research 20(3):629-642, 1972<br />
Goldmanm J. y H.A. Knappenberger. 'THow to determine the 282<br />
optimum number of operating rooms. Modern Hospital 111:<br />
114-116, 1968<br />
Revelle, C., D. Bigman y cola. "Facility location: A 290<br />
Review of context-free and EMS models. Health Serv.<br />
Res. 12(22):129-146, 1977<br />
Brodheim, E. y G. P. Prastacos. "The Long Island blood 308<br />
distribution system as a prototype for regional blood<br />
management. Interfaces 9(5):3-20, 1979<br />
Duraiswamy, N.,, R. Wetton y A. Reisman. "Using computed 324<br />
simulation to predict ICU staffing needs. J. Nur Admin.<br />
Febrmary, 1981, pp. 39-44<br />
Harrington, M. b. "Forecasting area-wide demand for health 330<br />
care services: A critical review of major techniques and<br />
their application. Inquiry 14-254-268, 1977<br />
James B., Henry and Rodney, L. Roenfeldt "Cost analysis 345<br />
of Leasing Hospital Equipment, Inquiry, 15 No.l,pp 33-37,<br />
1978<br />
Klarman, H.E. "Application of cost-benefit analysis to the 350<br />
health services and the special case of technologic<br />
innovation. Int. J. Health Serv. 4(2):325-352, 1974<br />
Warner, K.E. y R. C. Hutton. "Cost benefit and coat 378<br />
effectiveness analysis in health care. Med. Care 18(11)<br />
1069-1084, 1980.
- iii -<br />
Paqe No.<br />
Jackson, M.N., J. P. LoGerfo y cole. "Elective hysterectomy 394<br />
a coet benefit analysis. Inquiry 15(3):275-280, 1978 .........<br />
FINAL REPORT <strong>OF</strong> THE MEETING (In Spanish) ......................... 400<br />
List of Patiipant ........<br />
.. ............................ 419
FOREWORD<br />
These last years, <strong>PAHO</strong> with the support of Kellogg Foundation,<br />
has developed a series of workshops In Health Administration for<br />
Latin America and the Caribbean, such as Organizational Behaviour in<br />
Costa Rica, Evaluation and Health Planning in Barbados, Health Economics<br />
and Cost Control in Brazil, Epidemiological Approach to Decision Making<br />
in Chile, Management and Nurse Education in Panama, Strategic Management<br />
(or Planning) In Brazil, and as the latest Operational Research and<br />
System Analysis in Venezuela.<br />
The materials prepared for these workshops, all in Spanish,<br />
have been periodically sent to all existing Administration Programs in<br />
the Region, including those in the Caribbean. Clearly, this Subregion<br />
has not benefited from those documents, and this fact has been stated<br />
by our colleagues in the English-speaking countries of the Caribbean.<br />
Final reports from these workshops and other meetings were<br />
published also only in Spanish in <strong>PAHO</strong>'s "Revista Educaci6n Médica y<br />
Salud."<br />
During these meetings, new approaches to curriculum development,<br />
exchange of research information, selection of best bibliographic references,<br />
and the ,.nuice of articles that should be disseminated to our Region were<br />
discussed. This was accomplished through the input.of meeting participants.<br />
I have no doubt that these articles discipline oriented, are<br />
the tip of an iceberg of hundreds of publications which are periodically<br />
published all over the world. These reprints are being published in<br />
Spanish as books of readings for Latin American countries to support<br />
continuing education of faculties and post-graduate students.
In discussions about these publications with professionals<br />
in charge of the Administration Programs in the Caribbean, they<br />
expressed their frustration due to the lack of information on <strong>PAHO</strong>'s<br />
different progr-ms in English. Bearing this in mind, the Health Care<br />
Administration Education Program is reproducing some original articles<br />
In Engllish on Operational Research and System Analysis, selected<br />
during its Workshop in Venezuela,<br />
Humberto de Moraes Novaes, M.D.<br />
Regional Advisor in Health Care Administration Education
Workshop .- Education in Operational Research and System Analysis<br />
Caracas, Venezuela<br />
March 8-12,1982<br />
I. Introduction and Background<br />
A fundamental component of the World Health Organization's<br />
goal of health for all by the year 2000 is the development and<br />
support o£ .ealth administration programs. To Further this ob-<br />
Jective in Latin America and The Caribbean, a series of workshops<br />
has been sponsored by the Pan American Health Organization (PARO)<br />
and the W.K. Kellogg Foundation. These workshops have been con-<br />
cerned with organizational behavior, economics and financing,<br />
evaluation and planning, epidemiology, and administration. This<br />
particular workshop has dealt with the incorporation of Opera-<br />
tions Research and System Analysisltechniques in training and<br />
continuing education programs for healtb systems and hospital<br />
administrators.<br />
This workshop has been motivated by the fact that the health<br />
systems decision maker in Latin America is typically a physician.<br />
At present decisions are generally being made based on subjective<br />
grounds, without the use and, in many cases, the knowledge of<br />
the technic,l tools of operations research and system analysis.<br />
It is only recently that this situation has begun to change as<br />
quantitative methods are being included in both public health<br />
and continuing education curricula.<br />
As late as 1970, health operations research was non-existent<br />
in Latin America. In 1971, <strong>PAHO</strong> sponsored a symposium on system<br />
Systems analysis and operations research should be broadly<br />
defined as encompassing those quantitative techniques of management<br />
science which can be used to solve real world problems.<br />
These techniques may range from classical industrial engineering<br />
to mathematical programming.
-2-<br />
anc.> ,s which recommended that operations research at the hospital<br />
level become a priority.<br />
Also at this time, a summer program at the Instituto Tecnoló<br />
gico de Estudios Superiores de Monterrey, México was initiated, in<br />
which Industrial Engineers students and professors worked together<br />
with health managers in the definition and solution of management<br />
hospital problems. Since that time diferents modalities of this type<br />
of program have been carried out in other universities of colombia,<br />
Costa Rica, Perú, M¿xico and Brazil.<br />
At present thre are about 11 programs of industrial and<br />
systems engineering In which students and professors have-participated<br />
In health services research studies and 54 academic programs that<br />
after some form of training in health administration.<br />
The specific objectives of this particular workshop were to:<br />
1. Exchange experiences among participants relative to the<br />
teaching of operations research and system analysis applied to health<br />
care problems.<br />
2. Develop a basic plan for the teaching of operations<br />
-.search and system analysis.<br />
3. Select a basic bibliography for use in updating instructors<br />
and health services administrators and for use in the educational process.<br />
4. Design a basic program for continuing education in operations<br />
research r-d systems analysis for updating professors, researchers and<br />
administrators in the health sector.<br />
The 19 participants at the conference represented slx Latin<br />
American countries, the United States and <strong>PAHO</strong>. (see Appendix 1.).
-3.<br />
The format of the workshop was organized to allow partici-<br />
pants to expound on their perceptions of the problems involved<br />
in the training of Latin American health administrators in<br />
management science techniques. This enabled the group to form<br />
a concensus viewpoint from which specific problems could then<br />
be addressed, and recommendations formulated. These concerns<br />
can be summarized as follows: 2<br />
A. Health Concerns<br />
1. Physicians, wbo are the health decision makers,<br />
do not have knowledge of the technical tools of systems analysis<br />
and operations research. As a result, decisions are made on<br />
subjective and political bases without benefit of quantitative<br />
methodologies and information.<br />
2. There is a parallel need for the development and<br />
utilization of information systems in approaching health systems'<br />
problems. At present decisions are constantly being made without<br />
information at both the national and local levels.<br />
3. Middle managers require a knowledge of descriptive<br />
statistics, systems analysis and evaluation techniques to im-<br />
prove tLcir effectiveness.<br />
4. Public health administrators bave viewed those<br />
students being trained in management science techniques as a<br />
threat. This has led to the deterioration of training eiforta<br />
in at least one country (Colombia.)<br />
5. Effective teaching must be geared to demonstrating<br />
to health administrators how to apply methodologies to their<br />
2 For a specific example see: Carlos Perez, Improving the Managerial<br />
Capabilit'y of the Colombian Health System, May, 1981,<br />
included in the Appendix.
-4-<br />
prob.ems rather than straight lecturing, However, this requires<br />
a l,-ge amount of preparation time and such teaching aides as<br />
case studies and decision making laboratories. It is further<br />
constrained by the problem of a lack of proficient teachers who<br />
can communicate effectively with students. (See number B-1)<br />
6. In educating administrators, particularly physicians,<br />
there is also the problem that, given a little knowledge obtained<br />
via a short course, they may assume they know a lot; that is,<br />
"a little knowledge is dangerous."<br />
7. Health institutions have not created positions for<br />
teams who would apply management science techniques to their<br />
problems. Those that do, typically have only one position which<br />
is not satisfactory. Consequently, health institutions have not<br />
yet created a demand for operations research and system analysis<br />
techniques.<br />
8. There has been a tendency by operations researchers<br />
to focus on the micro level problems, neglecting the more signi-<br />
ficant problems which must be addressed on a national scale.<br />
For example, .the impact of improving the efficiency of a hospital<br />
is insigni-,cant compared to that of improving the quality of<br />
water or nutritional level in the region whicb that hospital<br />
serves. This is particularly true in rural areas.<br />
B. Educational Concerns<br />
1. Most university professors do not have sufficient<br />
background in applying systems analysis and operations research<br />
in the health field to effectivoly mutivate and educate health<br />
administrative students.
-5-<br />
2. Programs for bringing together schools of engineer-<br />
-,g, business and medicine are not, a priori, guaranteed to<br />
succeed.<br />
(Conversely, at Sao Paulo, Brazil,<br />
a Joint program between a business school and private hospital<br />
has proven to be successful.)<br />
3. An underlying problem in the educational process<br />
is that schools of administration are primarily oriented to the<br />
private sector. They have had little experience (and often<br />
little interest) in the public sector.<br />
4. Most Latin American professors of public health<br />
are physicians. They have typically shown a resistance to<br />
the participation of other disciplines in the education process.<br />
This has been true in the overwhelming majority of programs in<br />
Latin America.<br />
5. The Latin American universities typically don't<br />
have the financial resources to keep quality faculty. The<br />
result is that most leave for industry, consulting or jobs in the<br />
USA. Thus, obtaining and maintaining human.resources may be<br />
the most pressing problem facing educational institutions.<br />
6. There are both institutional and political barriers<br />
which prevent a public health school from developing a formal<br />
relationship witb a management school. Without these formal<br />
relations, it is very difficult to develop any type of educa-<br />
tional program. This type of intransiance may not be resolved<br />
until those who are reiponsible for budgotary decisions are<br />
cognizant of the situation and the necessity for its resolution.
-6-<br />
As a means of addressing these concerns, the workshop<br />
p4rticipants formulated a series of recommendations. These<br />
recommendations are oriented towards the development of both<br />
continuing education as well as more formal education programs<br />
for health administrators in which the techniques of systems<br />
analysis and operations research are presented. In addition,<br />
since it is also necessary to train practitioners of those<br />
metbodologies who will work in the health field, these types<br />
of programs have also been addressed. A fundamental belief<br />
of the participants is that these techniques, to be successfully<br />
applied in solving health problems, require an interdisciplinary<br />
team approach. They cannot be solved by individuals, neither<br />
administrators nor analysts, working independently. Conse-<br />
quently, the education of both administrators and practitioners<br />
must be addressed. Further, to be most effective, these educa-<br />
tion programs should overlap to as great as an extent as possible.<br />
Thus, as students, there is an opportunity for both future<br />
administrators and technicians to take courses together, work<br />
on group projects together, and develop the appreciation of each<br />
other's .iscipline and capabilities that will facilitate their<br />
working together in the future.<br />
The next section of this report contains the recommendations<br />
of the workshop. It is followed by a section giving more speci-<br />
fic details of the three levels of courses (short course, one<br />
year certification program, two year masters) that have been<br />
proposed.
II. R.commendations<br />
-7-<br />
A series of 22 recommendations bas resulted from the work-<br />
shop. Tbese have been categorized into five subsets: 1) educa-<br />
tional programs and additional workshops; 2) resources and<br />
teaching aides; 3) information exchange programs; 4) institutional<br />
curricula; and, 5) general recommendations. For each recom-<br />
mendation those individuals and institutions who should play<br />
the primary role in that recommendation's implementation bave<br />
been noted using the following codes:<br />
1. <strong>PAHO</strong> (the Pan American Health Organization.) Although<br />
<strong>PAHO</strong> has limited financial resources, it can continue, to assume<br />
the important roles of facilitator and knowledge base. Speci-<br />
fically, it is a function of <strong>PAHO</strong> to bring together the appro-<br />
priate índividuals and institutions in order that the recom-<br />
mendations might be implemented, Part of this facilatator role<br />
would involve the continued development of financial resources<br />
from both foundations and the involved governments as required<br />
for program implementation.<br />
2. EI (Educational Institutions.) This refers to those<br />
educational institutions in the different participating countries<br />
that would either provide the proposed programs directly or<br />
contract with other institutions for curricula and course devel-<br />
opment and offering.<br />
3. Agencies refers to federal, regional and community<br />
level agencies that would provide students and funding for the<br />
proposed activities; erve a¡t S)ll urco or data; und provide<br />
specific problem areas for study.
-8-<br />
OR/SA (Operations Research and Systems Analysis.)<br />
This is directed at the participants of the workshop as well<br />
as selected key individuals in the various Latin American<br />
countries who would be involved with the implementation of<br />
the recommended courses and program options.<br />
The specific recommendations are as follows. The re-<br />
commended, responsible parties are indicated by ( -) after each<br />
recommendation.<br />
A. Educational Programs<br />
1. Three types of courses should be developed for<br />
teaching operations research and system analyses to Latin<br />
American Health Administration students and practitioners.<br />
These courses could be given as part of a specific program or<br />
in a continuing education mode. The three formats are summar-<br />
ized below; specific details are left for the next section.<br />
a. Short courses geared primarily for adminis-<br />
trators and other practitioners. The typical short course would<br />
be from 16 to 40 hours in duration and wouldV be oriented towards<br />
showing the jtudent how the particular methodology would be used<br />
in solving realistic problems of concern.: A series of<br />
courses should be developed since it is unrealistic to expect<br />
that one course would be sufficient. The courses would have no<br />
methematical prerequisites. That would motivate the student<br />
towards an understanding of the system's perspective, an appre-<br />
ciation of information for making decisions and recognition that
-9-<br />
there are technically trained individuals who could apply man-<br />
,ament science techniques to the solution of health systems<br />
problems. Similar short courses would be geared to operations<br />
researchers and system analysts to enable them to more effec-<br />
tively function in the health field.<br />
b. One-year certification program of approximately<br />
240 bourd oriented towards the practicing administrator. This<br />
program would be geared to giving the administrator a more<br />
indepth knowledge of management science techniques. However,<br />
it would require only mathematical proficiency in algebra as a<br />
prerequisite.. The course should be designed as either an even-<br />
ing or weekend program to enable the administrator/student to<br />
continue to work fulltime.<br />
c. A "two-year" masters program. This would be<br />
directed towards the administrator who wishes to acquire a<br />
more rigorous background in operations research and systems<br />
analyses. It would require a knowledge of calculus as a mathe-<br />
matical prerequisite. A second masters program should be<br />
developed to train a technically oriented individual (industrial<br />
engineeL, computer scientist, mathematician or physicist) to<br />
function as a competent health systems problem solver. Based<br />
on the U.S. experience, such individuals would, over a relatively<br />
short period (e.g., five years) assume administrative positions<br />
in the health field and thus become a second source of quantita-<br />
tively trained administrators.<br />
As notud, suggested detail of these programs are given<br />
in the next section. Specific examples of short courses are<br />
given in the Appendix. (<strong>PAHO</strong>,EI,OR/SA.)
-10-<br />
2. Operations Research and Systems Analyses studies are<br />
depa-ient upon data. Informed decisions cannot be made without<br />
valid, reliable information. However, data and information are<br />
typically given little attention in most programs. Workshop<br />
participants strongly believe that PARO should organize another<br />
conference on data and informatics which would complete the<br />
series of workshops. This latter conference would address:<br />
data sources, collection procedures, design and development<br />
of information systems, data entry procedures, editing, reduc-<br />
tion, data processing, quality control, collation, simple data<br />
analysis, networking of data systems, information exchanges aDd<br />
other related topics. (<strong>PAHO</strong>.)<br />
3. A series of directed workshops should be developed<br />
and held in each country. The workshops should bring together<br />
policy makers from government (and, where applicable, private<br />
industry) to interact with technical experts. These workshops<br />
should be aimed at addressing a specific problem of health ser-<br />
vices delivery. (<strong>PAHO</strong>, Agencies, El.)<br />
4. A follow-up workshop should be held to address the<br />
problem of implementation and update these recommendations in<br />
light of the progress made since the original workshop. Parti-<br />
cular emphasis should be placed upon projects instituted and<br />
curricula developed following the first OR/SA workshop, The<br />
second workshop should emphasize the problems of program/project<br />
implementation with particular attention paid those political,<br />
cultural and I'inun¡'ial constraints that effect implementation.<br />
Participants should include attendees from the first workshop
-11-<br />
and selected individuals who have been involved with the imple-<br />
mr' ation of operations research and systems analysis projects<br />
on a regional or national level. (<strong>PAHO</strong>.)<br />
B. Resources and Teaching Aides<br />
Prior to the start of the conference, two extensive<br />
literature searches (Spanish and English) were commissioned by<br />
<strong>PAHO</strong> to srve as resource material both during the workshop and<br />
for courses that would result from the conference's recommen-<br />
dations. The literature searches were primarily directed towards<br />
papers and documents which would provide the basis for case<br />
studies in the teaching of systems analysts and operations re-<br />
search techniques to health administrators. A secondary concern<br />
were papers that would acclimate technically trained individuals<br />
to health services delivery problems.<br />
The Spanish (and Portugese) literature search was conducted<br />
by Dr. George Kastner who located 60 relevent articles, providing<br />
abstracts of 43. Given the limited number of publications found,<br />
no screening was done; rather, all articles were included for<br />
use during the workshop.<br />
Thc 'inglish literature wasreviewed by Dr, Richard Shachtman<br />
with assistance from Drs. Arnold Reisman and Larry Shuman.<br />
Unlike the Spanish literature, computer literature searches<br />
identified thousands of articles concerned with health system<br />
analysis and operations research.<br />
The resultant set of 116 articles and 24 books were selected<br />
to encompass eight subcateguries: project evaluation, manpower<br />
planning and scheduling, resource allocation, demand forecasting,<br />
cost benefit analysis, inventory control, technology assessment
-12-<br />
and caLchment area analysis. Since a primary audience was to<br />
be adr.nistrators, the level of mathematical detail was a concern.<br />
Thus, articles of a purely theoretical nature were eliminated as<br />
were those that required a sophisticated matbematical background.<br />
While the more recent literature was emphasized, a number of<br />
earlier articles which could be considered "classics" were in-<br />
cluded. Also, articles that addressed issues of national priority<br />
were selected. These latter group included a number of articles<br />
concerned with the evaluation and cost benefít analysis of<br />
various programs.<br />
5. Workshop participants reviewed tbe 116 English articles<br />
and have selected 42 that should be translated into Spanish.<br />
These articles would serve as resource documents and the bases<br />
for case studies to be used in conjunction with the three types<br />
of recommended courses. (The complete list of articles and the<br />
courses for which they would be applicable are given in the<br />
Appendix, along with a classification of those articles that<br />
were not initially recommended for translation.)<br />
In addition, 14 of the 43 Spanish articles and iO documents<br />
previously histr'ibuted by <strong>PAHO</strong> should be included in the final<br />
so, of literature recommended for use by the health administra-<br />
tion programs. Also included should be the list of 24 English<br />
language books and the supplemental bibliography (articles not<br />
selected for translation.) This will provide the instructor witb<br />
a substantial set of resources. While the books and supplemental<br />
articles will be in English, they should be most applicable in<br />
the Master's programs where students will have a proficiency in<br />
English (at least at the reading level.) (<strong>PAHO</strong>,EI.)
-13-<br />
6. In order to improve the quality of instruction and<br />
'he relevancy of course content, <strong>PAHO</strong> should facilitate the<br />
development of case studies and computer software as teaching<br />
aides.<br />
a. Several case studies, ranging in complexity from<br />
simple versions of material presently available in the litera-<br />
ture to more complex cases which may require 8-16 hours of class<br />
and laboratory time to complete, should be developed. Problems<br />
chosen should be representative of those faced by Latin American<br />
health administrators. Source material may be provided by<br />
agencies within the countries themselves and/or analysts involved<br />
in health systems problens. The precedent for this type of case<br />
development has already been established in non-health related<br />
areas where faculty members have developed relevent cases under<br />
the sponsorship of private industry. Other case studies may come<br />
by expanding particular articles from the literature searches.<br />
Authors should be contacted about rewriting certain articles as<br />
case studies.<br />
b. To enhance classroom lectures (as well as certain<br />
case s",ldies) computer software should be developed for use in<br />
laboratory sessions. Sample data sets should be obtained which<br />
will enable students to utilize the software in order to better<br />
understand particular techniques and their use in problem solving.<br />
As part of this effort, <strong>PAHO</strong> should encourage the interchange<br />
of information among Latin American universities. In particular,<br />
abstract- or tho>st, sl.tl.wJnt prui.j.cl.s ;nd thel thl.hes< dirucQted at<br />
health systems problems should be circulated. Such projects<br />
could provide both case study and laboratory material.<br />
(<strong>PAHO</strong>,EI,AGENCIES,OR/SA.)
-14-<br />
7. An initial effort has been made during the conference<br />
to identify gaps in the published literature. As shown in the<br />
table below there are a number of areas in both the Spanish and<br />
English literature where participants felt deficiencies exist.<br />
These deficiencies should be further spelled out by representa-<br />
tives from Latin countries. <strong>PAHO</strong> should then commission papers<br />
or initiate studies which would reduce these deficiencies.<br />
(<strong>PAHO</strong>,OR/SA,Agencies.)<br />
Area<br />
Systems Anal.<br />
Informatics<br />
Decision Anal.<br />
Oper. Research<br />
General<br />
D: Deficient<br />
S: Satisfactory<br />
E: Excellent<br />
Status of Literature<br />
Type of Course<br />
Certificate<br />
Short Course Program<br />
Span. Eng. Span. Eng.<br />
D D S D<br />
D D D D<br />
D E D E<br />
D E D E<br />
D D D D<br />
Master's<br />
Program<br />
Span. Eng.<br />
D D<br />
D D<br />
D E<br />
E E<br />
D D<br />
8. P-r.icipants and educational institutions should consider<br />
collaborating in the development of applicable software for<br />
selected microcomputers that could'be used both in an educational<br />
environment as well as for real problem solving. This would<br />
require that participants work on compatible machines, using<br />
common languages. The recent advances in microprocessor tech-<br />
nology will enable users to obtain computers capable of solving<br />
complex problems at relatively low cost. The cost of software
-15-<br />
cnve!opment will typically be more than the machine thus under-<br />
,.ng the importance of collaborative efforts (EI,OR/SA.)<br />
9. There is considerable overlap among the various work-<br />
shops that have been or will be sponsored by PARO. <strong>PAHO</strong> should<br />
continue to provide future workshops with information from<br />
previous caes, particularly when such subject matter is relevent<br />
to more than one workshop. (<strong>PAHO</strong>.)<br />
10. <strong>PAHO</strong> should investigate the feasibility of obtaining<br />
funds for the publication of a book in Spanisb, concentrating<br />
on operations research applied to health services problems and<br />
directed at Latin American audiences. Problems of regional and<br />
national concerns should be emphasized. Such a book might con-<br />
tain some of the case studies noted above. (<strong>PAHO</strong>, OR/SA.)<br />
11. <strong>PAHO</strong> should facilitate the preparation of an article<br />
describing the workshop process to appear in the appropriate<br />
professional public health journal . Such an article would help<br />
to encourage more activities of this type, and improve the<br />
communication among scientists of the different countries. (<strong>PAHO</strong>.)<br />
12. <strong>PAHO</strong> should facilitate the dissemination of relevent<br />
working ,)apers and theses prepared in the U.S. to Latin American<br />
educators. In particular, the Catalog of Hospital Management<br />
Engineering Technical Papers published by the clearinghouse for<br />
Hospital Management Engineering, American Hospital Association;<br />
selected citations from Hospital Management Abstracts, and<br />
brief summaries or abstracts of Master's theses related to<br />
health services problhns (possibly o>btined thrQough the Associa-<br />
tion of University Programs in Hospital Administration) should
-16-<br />
pericaiclly ba circulated to Latin American health administration<br />
prog. .s. (<strong>PAHO</strong>,EI.)<br />
C. Information Exchange Programs<br />
13. <strong>PAHO</strong> should arrange for the routine surveying of<br />
the relevent English and Spanisb health services literature.<br />
It should monitor major national and international meetings of<br />
the operations research societies and public health associa-<br />
tions. This information should be distributed to Latin American<br />
health administration programs on a scheduled basis. Also<br />
included should be a listing of applicable short courses and<br />
professional meetings in both the U.S. and Latin American counties.<br />
(<strong>PAHO</strong>,OR/SA.)<br />
14. The information exchange function of the workshops<br />
could be improved by having selected participants give formal<br />
presentations of specific projects on research activities.<br />
Such presentations could be in a seminar format. Such presenta-<br />
tions might be scheduled prior to the actual start of the work-<br />
shop. (<strong>PAHO</strong>.)<br />
15.,. In order to most eff.iciently introduce operations<br />
research anr systems analyses methodologies to health adminis-<br />
trators while developing a cadre of sophisticated technical<br />
analysts, primary emphasis should be placed on developing the<br />
short courses and the two year master's program. The develop-<br />
ment of the certification program, while important, should re-<br />
ceive less priority. As noted, a number of short courses should<br />
be developed with a varJity of: foriits and o>ntent to atiisfy<br />
identified target populations. (EI,OR/SA.)
-17-<br />
16. All participants sbould promote the development<br />
of -dalth operations research and systems analyses programs<br />
within industrial engineering, medicine, management and health<br />
administration departments/schools. An emphasis should be<br />
placed on instituting joint programs among the different dis-<br />
ciplines, p&rticularly when only one university is involved.<br />
(EI,OR/SA.)<br />
17. An important component of both the certificate and<br />
masters prograns should be the offering of at least one course<br />
in health operations research jointly with engineering, public<br />
health and/or the medical school. Such a course should involve<br />
at least one project in which students must function as an inter-<br />
disciplinary team. (EI.)<br />
18. While Latin American universities will become the<br />
predominant trainers of master'sstudents, U.S. and Canadian<br />
universities will remain the primary training facilities for<br />
Ph.D.s. Consequently, it is in the best interest of Latin Ameri-<br />
can universities to develop more formalized institutional arrange-<br />
ments with the appropriate U.S. schools and programs. Latin<br />
American ,liiversities should strive to assure that such U.S.<br />
programs remain relevent to and considerate of the educational<br />
needs of the Latin students. If possible, Ph.D. dissertations<br />
should be directed at problem areas that are also of importance<br />
in Latin America. (EI.)<br />
19. As health administration programs continue to<br />
develop in Latin America, it is important that strong, formal<br />
ties are developed with both industrial engineering/operations<br />
research and management programs. If such ties are not developed,
-18-<br />
manatement science techniques will not be effectively integrated<br />
int> che health administration curricula. (EI,Agencies.)<br />
E. General Recommendations<br />
20. <strong>PAHO</strong> can further facilitate the development of<br />
research projects and collaborative programs between U.S. and<br />
Latin America by providing information to participants and<br />
other key individuals on priority problem areas, countries with<br />
favorable political climate and potential funding sources. (<strong>PAHO</strong>,<br />
EI,Agencies.)<br />
21. It cannot be overemphasized that operations research<br />
and system analyses require interdisciplinary teams to suc-<br />
cessfully solve health services delivery problems. All programs<br />
and resultant curricula should carefully reflect this fact in<br />
their development and delivery. (<strong>PAHO</strong>,EI,Agencies,OR/SA.)<br />
22. In order for operations research studies to lead to<br />
successful implementations, it is important that the decision<br />
maker be integrated into the planning process. This is why<br />
health administrators, at all levels, must be cognizant of the<br />
value and use of management science techniques. (<strong>PAHO</strong>,EI,Agencies,<br />
OR/SA.)<br />
III. Specific Examples of Courses<br />
Three types of courses were considered by the conference<br />
participants: short courses, certificate programs and full<br />
masters' degree programs, It was felt that the initial emphasis<br />
should be placed upon the development of short courses, fol-<br />
lowed by the masters' degree prugrums und then the certificate<br />
programs.
A. Short Courses<br />
-19-<br />
Short courses, by their nature, will typically be 16-40<br />
hours in duration and either given intensively during a two<br />
to five day period, or spread over several weeks or one semester.<br />
Since it is impossible to cover much more than introductory<br />
material in one short course, the offering institution should<br />
design a series of related courses which may build upon one<br />
another and provide students with a more complete educational<br />
experience. In all instances, an, attempt should be made to<br />
include problems for students to solve, both individually and<br />
in groups. These "laboratory" sessions may also enable students<br />
to have some computer interaction with either a game; e.g.,<br />
simulation of a hospital or regional health system, or a simple<br />
resource allocation or forecasting model.<br />
Examples of short courses include:<br />
1. Stand alone course for hospital and health systems<br />
administrators. Typically, no mathematics background required,<br />
although some knowledge would be helpful. Course would present<br />
an introduction to the techniques of operations research and<br />
systems analysis with particular emphasis on understanding what<br />
these techniques can and cannot do. Students will gain a know-<br />
ledge of the OR approach, cost/benefit analysis, information<br />
systems, data sources, interdisciplinary teams.* Students will<br />
learn how to recognize problems that could be solved by these<br />
methodologies, how to estimate the approximate time and effort<br />
*These are suggestad topics to be included in the optimal course.<br />
It is recognized that no one course may sufficiently cover all<br />
of them.
-20-<br />
required for solution, how to recognize potential political<br />
barriers to implementation, and where to seek help in conducting<br />
such a study. Specific topics included in the course may be:<br />
"toy" or simplified decision problems, resource allocation<br />
problems, planning (PERT/CPM) and discounting. A team project<br />
in which an unstructured problem is formulated should also be<br />
included.<br />
2. A stand alone course for industrial engineers,<br />
operations research, or other technical disciplines who will<br />
become involved in solving health delivery system problems.<br />
Students will become familiar with health systems and the types<br />
of problems typically encountered. Solution procedures for these<br />
problems will be presented and discussed.<br />
Prototype courses:<br />
a. 40 hour course - Introduction to Operations Research<br />
and System Analysis for health Professionals.<br />
1. Introduction to the concepts of system analysis,<br />
planning, evaluation and decision making. This should include<br />
an overview, conceptual model of the systems approach as applied<br />
to health aelivery problems. This framework should then be used<br />
,.l referred back to as the topics are presented in more depth.<br />
2. Definition of a decision system, types of deci-<br />
sions that are made, types of models. Discussion of the levels<br />
of decision making.<br />
1. Introduction to modeling; the art of modeling;<br />
examplle m.,debl s ol' rt.le(v¢.nt heu llt.h syt.il.s pr
-21-<br />
4. Presentation of a case to be developed during<br />
the course or a mini-project to be carried out by participants.<br />
Emphasis should be on problem formulation. Solution of part<br />
of the problem may be achieved by "hands on" use of canned<br />
computer programs during laboratory session.<br />
5. Introduction to planning and evaluation approaches<br />
including flow charting, PERT (Program Evaluation and Review<br />
Technique), CPM (Critical Path Method), Gantt charts. Include<br />
actual examples with computer use optional. Also include dis-<br />
cussion of process and outcome evaluations with appropriate<br />
examples.<br />
6. Introduction to resource allocation models.<br />
Presentation of simple linear programming case study. Illus-<br />
tration of graphical solution technique. Discussion of assump-<br />
tions in problem formulation. Computer usage desirable.<br />
7. Introduction to data sources and data collection.<br />
Should review data management and processing concerns, data<br />
reliability issues, information systems and potential problem<br />
areas.<br />
8. Preparation for cost-benefit analysis and capital<br />
budgeting. Discounting (net present value), project costing,<br />
simple cost-benefit analysis example, definition and development<br />
of internal rate of return, and benefit/cost ratio should all<br />
be covered.<br />
9. Cost-Benefit Analysis. Definition of incremental<br />
benefits and costs; imlpact - incidence matrix; complete cost-<br />
benefit example, using hand calculations. Computer example<br />
desirable.
-22-<br />
10. Marketing health services. Basic definitions,<br />
distilction between selling and marketing; strategic planning;<br />
specific health applications.<br />
11. Introduction to uncertainty. Basic introduction<br />
to probability concepts, events, probability assessment and<br />
estimation. Concepts underlying Bayes rule, distributions,<br />
expectations.<br />
12. Decision Analysis including decision trees,<br />
alternatives, outcomes, experiments, values and their construc-<br />
tion. Analysis and interpretation of decision problems, simpli-<br />
fied case studies. Laboratory session should include a full<br />
decision analysis case.<br />
13. Forecasting and prediction techniques. Concepts<br />
of moving average, exponentialsmoothing, simple least squares.<br />
Interpretation of simple regression. Case study example; use<br />
of canned computer program desirable.<br />
14. Inventory and material management, Relevent<br />
costs in inventory system. Basic inventory models -- lot size<br />
and order le"ol.<br />
15. Implementation of operations research/systems<br />
anaiysis studies. Interdisciplinary teams; working with<br />
decision makers; validation of study results; roadblocks to<br />
implementation.<br />
b. 8-16 hour courses for health professionals*<br />
*These courses utilize the following text: Arnold Reisman,<br />
Systems Analysis in Health Care Delivery; Lexington, Massachusetts;<br />
Lexington Books, 1979.
Topic<br />
Introduction to<br />
Systems Analysis<br />
Systems Concepts<br />
Graphical Techniques<br />
Algebraic Techniques<br />
Data Collection<br />
Formal Aides to<br />
Creativity<br />
Art of Systems<br />
Analysis Strategies<br />
for Implementation<br />
One Day<br />
Course<br />
1 hr.<br />
1<br />
2<br />
1<br />
.5<br />
.5<br />
-23-<br />
Two Day<br />
Course<br />
1 hr.<br />
1<br />
5<br />
3<br />
1<br />
1.5<br />
Two Day<br />
Course<br />
With Math<br />
1 hr.<br />
c. Quantitative Methods Applied to the Administration<br />
of health care. (45 hours)<br />
This course is designed for health administrators,<br />
typically physicians and nurses, who bave limited mathematical<br />
and statistical background. The course, which is given at<br />
the University of Sao Paulo, Brazil, has been revised several<br />
times.<br />
1. Elements of Mathematics - cartesian coordinates,<br />
linear equations, elementary graphical solution procedures.<br />
2. Elements of Statistical Inference - set tbeory,<br />
probabilities, Bayesian probability, discrete distributions,<br />
continuous distributions, simple linear regression.<br />
3. Elements of Operations Research - critical path<br />
method, linear programming, queueing.<br />
1<br />
5<br />
8<br />
3<br />
1<br />
1.5
-24-<br />
d. Methods Improvements Techniques in Hospitals.<br />
This is designed as a stand alone course for bospital<br />
department heads and administrative staffs. Students must define<br />
and solve a real problem effecting their department. (40 hours)<br />
1. Introduction to Methods Improvement - scientific<br />
management; systematic approach to problem solving.<br />
2. Philosophy of Work Simplification - extension<br />
to hospital setting; problem identification; use of personnel<br />
in work simplification; PERT.<br />
3. Work Session in Problem Definition<br />
4. Process Analysis - definitions and symbolic nota-<br />
tion; flow diagrams; evaluation of flow diagrams and subsequent<br />
action.<br />
5. Operations Analysis - operation charting; motion<br />
economy; micro-motion-video motion techniques.<br />
6. Work Simplification - systematic examination of<br />
problems; what to look for; what to do; layout; automated<br />
systems.<br />
7. Work Session on Problem Analysis<br />
b. Work Sampling - sample size determination; proce-<br />
d,,re; interpretation of results.<br />
9. Other Data Gathering Techniques - time study;<br />
link analysis; questionnaires.<br />
10. Work Session on Measurement<br />
11. Cost Analysis - cost measures; cost estimates;<br />
non-monetary criteria; comparing methods.
-25-<br />
12. Elementary Statistics ior Analyzing Differences -<br />
testing results; interpretation of data.<br />
Studies<br />
13. Work Session on Evaluating Results<br />
14. Implementing the Results of Methods'Improvement<br />
15. Work Session: Reports and Critiques of Projects<br />
e. Health Systems Research Seminar<br />
This is a 45 hour course designed for both health<br />
administrative students and industrial engineering/operations<br />
research students who want to learn about the actual application<br />
of quantitative methods to health services problems. In addi-<br />
tion to classroom discussions, students form small, interdisci-<br />
plinary teams and solve an actual hospital or health system<br />
problem. Discussion topics have included:<br />
Research in Health<br />
microcosting.<br />
approach.<br />
Control<br />
1. Introduction to Industrial Engineering/Operations<br />
2. Evaluation of a Unit Dose Drug Distribution System<br />
3. Hospital Cost Models - step down cost allocation;<br />
4. Incentive Reimbursement - an industrial engineering<br />
5.<br />
6.<br />
7.<br />
8.<br />
Utilization Review Models<br />
Nurse Staffing Methodologies<br />
Predictive Reimbursement Models<br />
Grouping Hospitals for Reimbursement and Cost<br />
9. Operating Room Scheduling and Admissions System<br />
10. Linear Programming Applications: menu planning;<br />
theraputic radiology
C' ... cs.<br />
-26-<br />
11. Regional Planning - location of a network of<br />
12. Emergency Medical Services - information systems;<br />
simulation of EMS systems; evaluation of paramedic performance.<br />
13. Health Economic Analyses and Models<br />
14. Measuring the Effectiveness of Care<br />
f. Information Systems and the Evaluation of Quality of<br />
Health<br />
This 30 hour course is directed towards health services<br />
administrators and planners. It presents an overview of the use<br />
of information and data processing technology for control and<br />
utilization for administration and planning of health systems.<br />
1. Origin, nature and utilization of information in<br />
health systems; medical documentation; administrative records.<br />
2. Information for decision processes; importance<br />
and objectives of educating health personnel in informatics.<br />
3. Objectives of the users of information; functional<br />
levels; levels of centralization or distribution of information<br />
systems; impact of information on organizations.<br />
tration and planning.<br />
4.'Needs of administratorsJ information for adminis-<br />
5. Systems analysis; project, role of systems analysis;<br />
planning and control of projects; collection and distribution of<br />
data; process for implementation of information systems.<br />
6. Computers and automation: basic concepts, electronic<br />
data pisc:essing; files and logical structures;, data banks; com-<br />
puters and their components; data processing centers.<br />
7. Options in data processing: centralized, decen-<br />
tralized, and distributed systems.
-27-<br />
8. Applications of data processing to health systems;<br />
advantages and disadvantages for the use of computers in medicine.<br />
9. Information systems for evaluation and control;<br />
methods for evaluating the utilization and quality of services;<br />
medical auditing.<br />
g. Quantitative and Analytic Methods ior Health<br />
Administration*<br />
This 40 hour course seeks to: 1) create an apprecia-<br />
tion for, and an understanding of, the basic processes of sys-<br />
tems analysis modeling, decision making and control; 2) identify<br />
the intimate roles these processes play in the activities and<br />
responsibilities of the health administrator. Some of the more<br />
fundamental decision/control models and methodologies of systems<br />
analysis, management science, and economics are discussed.<br />
Strengths and limitations of these models for more effective<br />
health decision making are Stressed. Prerequisites for this<br />
course include college algebra, basic linear algebra and ele-<br />
mentary probability and statistics. Topics include:<br />
1. Overview of the Systems Analysis and Operations<br />
Researc.,/"!anagement Science Health-Related Literature<br />
2. Systems Approach and Systems Analysis - A Pro-<br />
logue for Health Care Decision Making<br />
3. Quantitative Models and Their Role in Health Care<br />
Decision Making and Control<br />
4. Simple Deterministic Decision Models: Inventory<br />
and Project Management<br />
*Course developed by Barnett R. Parker, Ph.D., School of Public<br />
Health, University of North Carolina, Chapel Hill, N.C.
cal ~Pogramming<br />
Sensitivity Analysis<br />
-28-<br />
5. Complex Deterministic Decision Models: Mathemati-<br />
6. Solving Linear Programming Problems by Computer;<br />
7. Generation of Data Appropriate to the Bealth Care<br />
Decision Making Task: Techniques of Measurement<br />
8. Goal Programming and Integer Programming Applica-<br />
tions to the Health Sector<br />
9. Cost-Benefit/Cost-Effectiveness Analysis: A fun-<br />
damental Mode of Thinking in Health Care Decision Making<br />
10. Feedback, Control and Program Evaluation for More<br />
Effective Health Care Management<br />
11. Guest Speakers - Special Topics<br />
B. Certificate Programs<br />
This program would be directed towards the working<br />
health administrator who is seeking more indepth knowledge than<br />
is provided through a series of short courses. It is also for<br />
the individual who is seeking a career change. Middle level<br />
managers would take this program as one step in advancing to a<br />
higher management position. The program would typically be 240<br />
hours. It would require a mathematical background through algebra.<br />
The graduate of the program should be able to formulate and<br />
solve simple quantitative problems (linear programming and queu-<br />
ing); perform an elementary cost-benefit:analysis; collect and<br />
reduce daita (descriplive statitl.i's); use "canned" computer<br />
programs for analysis; formulate (but not solve) more complex
-29-<br />
problems. The graduate should have a basic understanding of the<br />
couts involved in providing health services. The interdiscipline<br />
team concept should be stressed. A team proJect of 2-3 month's<br />
duration should be included.<br />
Courses in the program should include an introduction to<br />
quantitative methods (e.g., short course c.); a more rigorous,<br />
course in applying quantitative metbods (e.g., short course e.<br />
or g.); an introductory course in bealth economics; an introduc-<br />
tory course in biostatistics; and a course in information systems.<br />
Optional courses to be considered are: theory of health planning<br />
and evaluation; quantitative methods of planning and evaluation;<br />
and health organization behavior.<br />
C. Masters' Program<br />
Two forms of Masters' programs were discussed. The<br />
first would be directed towards hospital and health systems<br />
administrators who required more extensive educational training<br />
than offered under a certificate program. While students might<br />
be fulltime administrators, they would be expected to spend the<br />
necessary time in residence at an academic institution. The<br />
mathematical background should include college mathematics through<br />
calculus. This program would include all the courses listed<br />
under the certificate program, Also included would be an advanced<br />
course in statistics, a second level course in operations research<br />
methodologies (probabiliitic models), and an introductory course<br />
in econometrics. Students would carry out two or three team<br />
projects during the program. Thebe projects could be done as part<br />
of an interdisciplinary course (e.g., short course e.).
-30-<br />
The second type of Masters' program would be for engineer-<br />
in 6 andergraduates who wanted to solve health and hospital sys-<br />
tems problems. The program would provide a strong emphasis in<br />
operations research methodologies. In addition, students sbould<br />
become familiar with cost accounting concepts, economic prin-<br />
ciples and information systems. Graduates of this program would<br />
be expected to perform a number of the following functions:<br />
1. Solve linear programming and inventory problems;<br />
2. forumulate and analyze stochastic models;<br />
3. perform indepth statistical analyses (ANOVA and mul-<br />
tiple regression);<br />
4. design data collection studies;<br />
5. program in a high level computer language (FORTRAN,<br />
Pascal or PL-1);<br />
6. design program evaluation;<br />
7. conduct computer simulations;<br />
8. write technical reports;<br />
9. interact with decision makers and work as part of an<br />
interdisciplinary team;<br />
10. take unstructured problem, abstract it, formulate a<br />
mathematical model, obtain solutions and implement the best,<br />
acceptable solution;<br />
11. conduct long range planning studies.<br />
IV. Articles to Translate Into Spanish<br />
As b¡oted, an extensive literature search was prepared prior<br />
to the start of the conference. From this list, a total of 41<br />
articles were recommended for translation. These are summarized
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Lblo-w. Also given is that type of program (short course, cer-<br />
-ficate, masters') for which the article would be most bene-<br />
ficial.<br />
Senior Author Year Published Applicable Program<br />
Berkson<br />
Escudero<br />
Fetter<br />
Frerichs<br />
Greenland<br />
Hartunian<br />
Lev<br />
Meredith<br />
Nutting<br />
O'Connor<br />
Reisman<br />
Shoenbaum<br />
Shuman<br />
Vracin<br />
Duran<br />
Hancock<br />
Hindle<br />
Reisman<br />
Abernathy<br />
Goldman<br />
ReVelle<br />
Brodheim<br />
Duraiswany<br />
Harrington<br />
Centerwall<br />
Couch<br />
Eisenbe.¿<br />
Henry<br />
Klarman<br />
McGregor<br />
Muller<br />
Schwartz<br />
Willems<br />
Warner<br />
Kendall<br />
Jackson<br />
Evans<br />
McNeJ1( 2 )<br />
Nemhauser<br />
Parker<br />
1. Optional<br />
2. Series of three<br />
1979<br />
1980<br />
1980<br />
1975<br />
1981<br />
1980<br />
1976<br />
1976<br />
1981<br />
1972<br />
1978<br />
1976<br />
1974<br />
1979<br />
1980<br />
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1981<br />
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1981<br />
1975<br />
1975<br />
1975<br />
Masters<br />
X<br />
X<br />
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xX<br />
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xX xxxxx<br />
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X<br />
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xX xX<br />
xX<br />
xX<br />
xX xX<br />
xX<br />
articles in NEMJ 293:211-226<br />
Certificaté<br />
x<br />
X<br />
X(1)<br />
X<br />
X<br />
X<br />
X<br />
X<br />
X<br />
X<br />
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X<br />
X<br />
X<br />
X<br />
X<br />
X<br />
X<br />
X<br />
X<br />
X<br />
X,<br />
X<br />
X<br />
X<br />
X<br />
X<br />
X<br />
X<br />
X<br />
8hort<br />
Course<br />
X<br />
X<br />
X<br />
X<br />
X<br />
X<br />
xX<br />
X<br />
X<br />
X<br />
X<br />
x( 1 )<br />
x<br />
X<br />
X<br />
X<br />
x()<br />
X<br />
x(1)<br />
X<br />
X<br />
X<br />
X<br />
X<br />
x'
-32-<br />
!n addition to these works in English, it was recommended<br />
that eAHO also distribute a number of the works already in<br />
Spanish. Included in this second list are several papers that<br />
have been published by <strong>PAHO</strong>. It was recommended that all of these<br />
PAIO publications be included in any distribution of papers.<br />
Recommended Spanish articles are:<br />
Senior Author<br />
Year Published<br />
Ackoff 1974<br />
Barrenechea 1978<br />
Dunia 1976<br />
Miembros Facultad<br />
de Ingenieria 1974<br />
Grundy,Reinke 1974<br />
Marin 1978<br />
Novaro 1973<br />
Rodrigues 1978<br />
Schmidt (p.47) 1980<br />
Schmidt 1981<br />
Schmidt (p.50) '1981<br />
Instituto Monterrey 1976<br />
Applicable Program<br />
SIhort<br />
Masters Certificate Ciourse<br />
X<br />
X<br />
X<br />
X<br />
X<br />
X<br />
X<br />
t<br />
X<br />
X<br />
X<br />
X<br />
X<br />
X<br />
X<br />
X<br />
X<br />
X<br />
X<br />
X<br />
X<br />
X<br />
X<br />
X<br />
X<br />
X<br />
X
- 33 -'<br />
-Case Mix Definition by Diagnosis-Related Groups<br />
ROBERT B. FETTER, YOUNGSOO SHIN, JEAN L. FREEMIAN,<br />
RICHARD F. AVERILL AND JOHN D. THOMPSON
- 34 -<br />
Case Mix Definition by Diagnosis-Related Groups<br />
ROBERT B. FETTER,* YOUNGSOO SHIN,. JEAN L. FREEMAN,t<br />
RICHARD F. AVERILL,§ AND JOHN D. THOMPSON I<br />
Froml tite Centerfor for Healtl Stulies,<br />
lnstitlio, jbr Social ail Iu lie! .Stdies.<br />
Yale Untivcrsitu<br />
, Professor. School of Organization and Management, atad Institution for Social and Policv Studies.<br />
f Assistant Professor, Department of Preventioe Medicine, College of Medicine, Seoul National University,<br />
$eoul, Korea.<br />
Assistant in Research, Centerfor Healthl Studies, Institution for Social ard Polcy .Studies.<br />
A4 Asociate Directorfor Research, Health Management Program, School of Organization and Managemnent.<br />
! Profeasor of Public dealth, School of Medicine, and Institution for Social and Policy Studies.<br />
The research reported herein was performed pursuant to Contracta No. HCFA 600-75,0180 and No. HCFA<br />
77-0043.from the Health Care Financing Administration, Department of Health, Education and Welfare.<br />
~Iblcation of this monograph was supported by Contract No. 600-7540180, from the Health Care Financing<br />
;dmintstration, Department of Health, Education and Welfare. The opinions and conclusions expressed hefan<br />
are souely those of the authors and should not be construed ao representing the opinions or policy of any<br />
ncg of the United States government. Copies of a more detailed description of this research are available by<br />
tíilng to Al Esposito, Director, Division of Hospital Experimentation. Office of Demonstrations and Evaluan.<br />
ffe of Researcl. Demostrations.<br />
a;ud Staristics. It¿clrt Car;' Fiarswinag Adtlrnisltratio,, Rolmoai E16.<br />
Meadows Buildhig,. 6401 SecuritSV Blvd., Bualtimore. MD 21235. Requests should be made for AUTOGRP<br />
,latient Classfication Scheme atad Diagnosis Related Grmlps (DRGs). Health Care Financing Grants and<br />
V ontracts Report Series, HEW Publication No. (HCFA) 03011 9-79. Inquiries regarding the software aeailable<br />
íor analyses with AUTOGRP and DRCs should be made in writing to Ma. Marla DeMusis, SOM, 12 Prospect<br />
'tce, New Haoen, CT 06520.
- 35 -<br />
Acknowledgment<br />
The authors wish to acknowledge the support, insights, and cooperation during this<br />
research of Al Esposito, Project Olficer, Health Care Financing Administration, Department<br />
of Health, Education and Welfare. The successful completion of this research<br />
relied heavily on the programming skills and patience of Enes Elia, Senior Systems<br />
Prograromer, and the excellent administrative support of Ann Palmeri and Maria De-<br />
Musis. The assistance of the New Jersey Department of Health, especially Michael J.<br />
Kalibon in preparing the description of the New Jersey prospective reimbursement<br />
system is greatly appreciated. The material presented on the case mix approach to<br />
hospi:1I regional planning is based on the current doctoral research of Robert Chemow.<br />
The authors are indebted to the many physicians who, dunng the years of development<br />
of the DRCs, participated in their formuluation and evaluation.<br />
The research reported here represents the current stage of development of the<br />
Diagnosis.Related Groups. The initial work on the approach and associated technology<br />
for patient classification began nearly a decade ago. Significant contributions were made<br />
during the course of this research by Donald C. Riedel, Ronald E. Milis, Lesley Mills<br />
and Phyllis Pallett.<br />
Supplement to Medical Care Volume 18, Number 2<br />
ilEDICAL CAPE (ISSN 00257079) IspublishedmonthiybyJ. B.LippincottCompny. East Washington Square. Philadelphia.<br />
A 19105. Subsciption address: Joumai Fulfillment Deamnent. UippincontHap . 2350 Virginia Avenue. Hagersntwn. MD<br />
1740. Subcriptiion ates: United Stater and U.S. Possessions. one yer, $36.00; special price US. students. 20.00; all other<br />
untriesexceptJapanone year, 42..00. Single copies $5.00. Subscriptionorders and correspondencecncerning subscriptions in<br />
JabPon should be ent to Woodbell Scope. 1 1-1 Shoto 2-chome. Shibuya-ku. Tokyo 150. Japan. Printed in U.S.A. Copyright()<br />
!980by J. 8. LLppinco« Company. Second clas postage paid at Hagerstown. Maryland, and additional mailing ofrices.
- 36 -<br />
Prsfact<br />
DURING THE PAST DECADE, health care financing researchers have sought to<br />
develop equitable methods to constrain the rate of increase in health care<br />
expenditures. Tle ced l for a stccessfidt national Iiospital cost containment<br />
program has been highlighted as a major step toward overall health care cost<br />
containment and a comprehensive national health plan.<br />
In early efforts to compare and control hospital costs, researchers calculated<br />
product costs by unit of service, such as lab tests, rad;ology tests, or days of<br />
routine heoel service. Several incentive schemes were devised to encourage<br />
hospital effic iency and low unit cost. Experience has shown that focusing on unit<br />
cost alone encourages increased length of stay and ancillary utilization and<br />
argues that attenttioi shloutld ie li>ciisetd oni medlical-practice I);itterns.<br />
Recently, much attention has been ftcused on the cost per patient stay or per<br />
case treated. Shifting to a single hospital product required that techniques be<br />
developed to adjuist for variations in hospitals' patient or case mix.<br />
To group hospitals with a similar case mix, researchers hlave generally concentrated<br />
on proxy measures, such as the mix of services or t:fcilities available in each<br />
hospital. While these approaches are relatively easy to calculate, thféy normally<br />
do not address either the extent or the use of a hospital's available services or<br />
facilities.<br />
What is required is a classification scheme that is both manageable in terms of<br />
the number of case types defined and reasonable in terms of the variation in<br />
resources needed to treat each case type. This should permit direct measurement<br />
of a hospital's case mix.<br />
The development of the Diagnosis-Related Groups (DRGs) represents a significant<br />
step in case mix measurement and application for reimbursement purposes.<br />
DRGs classitfy 383 types of cases encountered in the hospital acute-care<br />
setting. Each DRG represents a class of patients requiring similar hospital<br />
services. Since DRGs are medically meaningful, they help provide a common<br />
basis for comparing cost effectiveness and quality of care delivered. DRGs also<br />
have the potential to assist the ho.¿,ital administrator as he manages his institution<br />
and communicates with the medical staff.<br />
Many PSROs have already explored the use of DRGs to review length-of-stay<br />
and treatment patterns. New York and Maryland have incorporated the DRG<br />
concept into their hospital cost containment programs and both New Jersey and<br />
Georgia ,tili soon be incorporating DRG methodologies in new hospital cost<br />
containment programs. At the federal level, DRGs are being considered for<br />
incorporation in new reimbursement procedures for acute care hospitals. Given<br />
the current emphasis on hospital cost containment, the development of DRGs is<br />
both an important and timely advancement of the health Ce,'e financing field.<br />
JAMES M. KAPLE<br />
Acting Director<br />
Office of Research, Denmonstrations aund Statistics<br />
Health Care Financing Administration<br />
Department of Health, Education, and Welfare
ML ICAL CAE1<br />
Februurl 1980, Vol. XVIII, No. 2, Supplement<br />
THE MAJOR FUNCTION of a hospital as an<br />
acute-care :npatient facility is to provide<br />
the diag.lostic and therapeutic services required<br />
by physicians in the clinical<br />
management of t'neir patients. In addition,<br />
the hospital also makes available certain<br />
hotel and social services such as meals,<br />
laundry and counseling, to patients while<br />
they are residents at the institution. Considered<br />
as an economic enti.y, the l: spital's<br />
outputs are the specific services it provides<br />
in temis of hours of nursing care,<br />
medications and laboratory tests. Its inputs<br />
are the labor, material and equipment used<br />
in the provision of these services, Each<br />
patient receives a specific set of outputs or<br />
services which is referred to here as a<br />
product of the hospital.<br />
For example, consider a patient under<br />
treatment for uncomplicated pneumonia.<br />
His hospital stay may last 6 days. Depending<br />
on his treatment process, he coulld receive<br />
several chest roentgenograms, a<br />
sputum Gram stain and culture, a blood<br />
culture, several complete blood counts, a<br />
urinalysis, routine blood chemistries, 2<br />
days of oxygen therapy, 2 days of IV fluids,<br />
2 days of IV penicillin followed by 4 days of<br />
IM penicillin and a supply of oral penicillin<br />
to b, .. !-"n at home. During his stay, he<br />
will a:so require various amounts and<br />
levels of nursing care. This set of outputs<br />
constitutes a product ordered by the physician<br />
and provided by the hospital to the<br />
patient in addition to meals and other hotel<br />
services. Each department within the facility<br />
consumes a certain amount of inputs in<br />
terms of standard labor, material and overhead,<br />
depending on the output produced.<br />
Por the radiology department, this would<br />
include the films, the technician time, and<br />
a portion of the departmental overhead ex-<br />
- 37 -<br />
1. Introduction<br />
penses for the equipment and space<br />
utilized in the production of the various<br />
types of roentgenograms.<br />
Since individual patients receive different<br />
amounts and types of services, the hospital<br />
may be viewed as a multiproduct firm<br />
with a product line that in theory is as extensive<br />
as the number of patients it serves.<br />
The particular product provided each patient<br />
is depeúdent upon his condition as<br />
we 11 as the treatment process he undergoes<br />
during his stay. For example, in most instances<br />
an ulcer patient with a major surgical<br />
procedure such as an exploratory<br />
laparotomy or gastric resection requíies<br />
more units of physician and nursing time,<br />
more medication, more ancillary services<br />
and remains hospitalized at least 10 days<br />
longer than a woman admitted for a normal<br />
delivery. The formér case is generally referred<br />
to as more complex since it rece;ves<br />
mnore of the institution's outputs in ternis of<br />
nursing time, meals, laboratory tests, and<br />
special services than the latter case. During<br />
any specified time period, an institution<br />
admits and discharges a variety of<br />
cases representing different levels of complexity.<br />
The relative proportions of the different<br />
types of cases the hospital treats are<br />
collectively referred to as its case mix.<br />
Historically, patient-days of care and the<br />
number of admissions or discharges have<br />
been used to describe hospital output<br />
while cost per patient-day, per cent occupancy<br />
and mortality rate have been used to<br />
evaluate hospital performance. Such<br />
aggregate measures presented out of context<br />
of the types of cases treated by an institution<br />
and their relative complexity is<br />
not particularly useful infonnation to hospital<br />
management for internal assessment<br />
of efficiency and effectiveness nor to reg-
CASF MIX DEFINITION BY DRG<br />
- 38 -<br />
ulatory agencies for inter-institutional<br />
comparisons. In particular, the ovutcome<br />
ancd cost of the individual patient care<br />
processes that give rise to the hospital<br />
products cannot be adequately determined.<br />
As a cose(ltence, admiiiiiistrators and<br />
clinicians caninot ascertain the quality aud<br />
cost iimplications of the treatment plans<br />
practiced withi.. the insitution nor can regulators<br />
assess the impact of alternative<br />
mietlhods aross institutions.<br />
In order to evaluate, conmpare, and provide<br />
relevant feedback regarding hospital<br />
perl>onnaiice, it is necessary to idcntity the<br />
specific products that institutions -,rovide.<br />
As defiled above, a hospital product is a set<br />
of services provided to a patient as part of<br />
the treatment process coiltrolled by his<br />
clinician. While each individual patient<br />
adlmitted to an institultion is unique, he has<br />
certain demographic, diagnostic and<br />
therapeutic attributes in common with<br />
other patients that determine the type and<br />
level of services he receives. If these classes<br />
of patients with the same clinical attributes<br />
and similar processes of care can be<br />
identified, then the framework within<br />
which to aggregate patients into case types<br />
is established. Moreover, if these classes<br />
cover the entire range of inpatients in the<br />
acutte-care setting, then collectively they<br />
constitute a classification scheme that provides<br />
a means for examining the products<br />
of the hospital, since patients within each.<br />
class are exr-cted to receive a similar<br />
product.<br />
The means of defining hospital case mix<br />
for this purpose is the construction and ap-<br />
Flication of a classification scheme comprised<br />
of subgroups of patients possessing<br />
similar clinical attributes and output utilization<br />
patternls. This itnvolves relating the<br />
demographic, diagnostic and therapeutic<br />
characteristics of patients to the output<br />
they are provided so that cases are c"rerentiated<br />
by only those variables related to<br />
lihe c
X;' VIII, No. 2. Suippllce,t<br />
- 39 -<br />
,'lirst and second sets of patients incurred<br />
Ily 13 and 30 per cent, respectively, of the<br />
'tosts incurred by the latter. Thus, the<br />
:'type of surgery performed and the pres-<br />
,ence or type Jfsecondary diagnosis make a<br />
.considerable difference in the hospital<br />
!!product provided to the patient. Foi .ais<br />
reason, patient case types determined<br />
solely by primary diagnosis is not acceptable<br />
for use in defining hospital case mix,<br />
since it is not precise enough to account for<br />
either the condition of the patient or the<br />
complexity of the treatment protocol.<br />
Another patient classification scheme in<br />
'wide use is that developed by the Professional<br />
Activity Study (PAS) of the Comnmission<br />
on Professional and Hospital Activities<br />
(CPHA), which publishes tables of<br />
length-of-stay statistics based on data from<br />
'jarticipating hospitals.' These tables present<br />
summaries on the basis of primary<br />
diagnosis, the presence of additional diag-<br />
An>ses, the presence of any surgeries, and<br />
'.age. Specifically, the PAS classification di-<br />
.vides all possible prinimary diagnoses into<br />
.349 mutually exclusive major diagnostic<br />
categories. Each of these major diagnostic<br />
categories is then divided on the presence<br />
: or absence of a secondary diagnosis, pres-<br />
; ence or absence of any surgery and 5 age<br />
.categories (0-19, 20-34, 35-49, 50-64,<br />
! 65+).tf This results in 20 subcategories for<br />
;; each of L ' 49 major diagnostic categories<br />
V~for a to.al of nearly 7,000 patient classes.<br />
iThe information is currently used exteni'<br />
sively by Professional Standards Review<br />
'Organizations (PSROs) in setting lengthi.;of-stay<br />
checkpoints as part of their concur-<br />
.'rent review process.<br />
5 Although the PAS scheme takes into ac-<br />
',count additional patient attributes such as<br />
,secondary diagnosis, age and information<br />
:related to the treatment process, such as<br />
operation status, these attributes still may<br />
f For major categories 342-349, pertaining exclu-<br />
'sively to newboms, birthweight is used in place of<br />
age.<br />
INTRODUCTION<br />
be insufficient in certain instances to describe<br />
adequately a case in terms of output<br />
utilization. Refer to the example described<br />
above were the specific type of operation<br />
differentiated one set of surgical ulcer patients<br />
from another. Thus, because of its<br />
uniform structure throughout all 349 diagnosis<br />
groups, the PAS scheme tends to<br />
overspecify in some diagnostic categories<br />
where the extra variables may not be partictilarly<br />
relevant as regards uitilization of<br />
t:acilities and underspecify in others where<br />
more precise information is required.<br />
As an alternative patient classification<br />
scheme, the Diagnosis-Related Groups<br />
(DRGs) have been constructed, based on a<br />
procedure referred to as the significant attribute<br />
method. The fuindamental piurpose<br />
of the DRG approach is to identifv in the<br />
hospital acute-care setting a set of case<br />
types, each representing a class of patients<br />
with similar processes of care and a predictable<br />
package of services (or product)<br />
from an institution. Using this Ipproach,<br />
the entire range of diagnostic codes was<br />
initially divided into broad disease areas,<br />
such as Diseases of the Eye, Diseases of<br />
the Ear, Cerebrovascular Diseases, and Infectious<br />
Diseases. Each of these categories<br />
was further subdivided into groups based<br />
on values for those variables that demonstrated<br />
an effect in predicting output as<br />
measured by length of hospital stay. It was<br />
decided to use length of stay (LOS) as opposed<br />
to some other output measure since<br />
it is an important indicator of utilization, as<br />
well as being easily available, well standardized,<br />
and reliable. The use of LOS and<br />
its relation to other measures is discussed<br />
further in the next section. The 383<br />
DRGs that resulted from this process are<br />
interpretable fromi a medical perspective<br />
as well as similar with respect to their patterns<br />
of length of stay.<br />
This supplemnent presents a description<br />
of the approach implemented to construct<br />
the DRGs and a discussion oftheir application<br />
in a number of health care settings.<br />
Section 2 provides information regarding
CAsE MIX DEFINITION BY DRG<br />
- 40 -<br />
the: data base, the statistical methodology,<br />
and the general process by which the<br />
methodology was applied to the data in the -,<br />
formation of the groups. At the end of Section<br />
2 is an example illustrating the procedure,<br />
to which readers may initially refer<br />
1 :<br />
f<br />
i<br />
1<br />
.Í<br />
M EDICAL CA}t<br />
for a general understanding of DRG construction.<br />
A discussion of the interpretation<br />
ana application of the DRGs in utilization<br />
review, budgeting, cost control, prospec.<br />
tive reimbursement and regional planning<br />
is found in Sections 4 through 6.
- 41 -<br />
dMLDICAL C.ARE<br />
'.Fcbrtanj 1980, Vol. XVIII. No. 2. Supplemnent<br />
£^ ^ .. .-. . 1. 1<br />
i. C;onstructlon ot u<br />
,IT PRIMARY OBJECTIVE in the construc-<br />
.tion of the DRGs was a definition of case<br />
types, eas"h of which could he expected to<br />
receive similar outputs or services from a<br />
hospital. In order that the set of d
CAME MIX DEFINITION BY DRG<br />
- 42 -<br />
'I~e use of LOS as a imeasure of case complexity<br />
has been studied by other researchers.<br />
Luke in his work on case mix measurement"l<br />
established the high degree ok<br />
correlation between LOS and total charges<br />
rendered the patient. Lave and Leinhardt<br />
found significant correlation between LOS<br />
and measures of case mnix complexity.'?<br />
The process sI lorming the DRCGs was<br />
beguin bIy partitioning the data )base into<br />
mutntally exclusive and exhaustive primary<br />
diagnostic areas, called Major Diaglnostic<br />
Categories. Each nmijor c;ategory was then<br />
examined separately and filrther subdivided<br />
into groups based on values of<br />
variables suggested by the statistical algorithmn.<br />
Physician review of these recommended<br />
subdivisions often led to modification.<br />
Thus, at each stage of the process<br />
the suhgroups were hased both on statistical<br />
criteria as well as physician judgment.<br />
The precise variables that were included<br />
in class definitions varied across the major<br />
categories. For example, age was determined<br />
to be important in explaining utilization<br />
for hernia patients, but not an important<br />
factor for gastric ulcer patients. From<br />
each Major Diagnostic Category, a number<br />
of final patient classes was formed. These<br />
final patient classes are the DRGs. A more<br />
extensive discussion of the data base, the<br />
statistical algorithm, and the general<br />
strategy used in constructing the DRGs is<br />
presented in the following subsect:ons.<br />
2.1 Data Base<br />
The data base used to construct the<br />
scheme contained approximately 500,000<br />
hospital records from 118 institutions in<br />
New Jersey, 150,000 records from 1 Connecticut<br />
hospital and 52,000 records of federally<br />
funded patients from 50 instittutions<br />
in a PSRO region. These records contained<br />
demnoglrphic inlfornation al>out each patient<br />
(e.g. sex, age) as well as clinical and<br />
diagnostic information related to his hospital<br />
stay (e.g. pro)lemns/(liagnoses, surgical<br />
procedures, special services used).<br />
MEDICAL CARE<br />
Diagnostic information in the data base<br />
was coded with both classification systems,<br />
ICDA8 and HICDA2. Since there is not a<br />
tlFect inatch between the 2 schelimes, data<br />
from all hospitals could not be combined in<br />
a unified data base. Thus, it was decided to<br />
construct the classification scheme using<br />
the miore prevalent ICDA8 codes as the<br />
standard. The ICDA8 version was then<br />
translated to HICDA2. This translation<br />
was evaluated with hospital dato. and<br />
itecessary modlitficatioiis were miade to insure<br />
the consistency of the classification<br />
across the 2 coding schemes. Both ICDA8<br />
and HICDA2 record surgical procedures<br />
tsiíng 3-digit codes. These procedure<br />
codes cover not only operations performed<br />
but also some therapies and minor diagnostic<br />
procediures. For ICDA8, the ranges of<br />
codes that were considered to reflect actual<br />
operations were 010-999 and A10-A59.<br />
Likewise, for HICDA2, the actual code<br />
range for operations is consjdered to he<br />
010-920 and 933-936. In constructing the<br />
patient classification scheine, only codes<br />
within these ranges were considered as<br />
surgical procedures.<br />
2.2 Statistical Methodology<br />
The particular statistical methodology<br />
employed is a variation of the Automated<br />
Interaction Detector (AID) method of<br />
Sonquist and Morgan, which has previously<br />
heen applied in the analysis of conmplex<br />
saniple survey data at the UniversitY<br />
of Michigan Survey Research Center.2?<br />
The objective of this approach is to<br />
examine the interrelationships of the variables<br />
in the data base and to determine, in<br />
particular, which ones are related to sonme<br />
specified measure of interest, referred to as<br />
the dependernt variable. This is accomplished<br />
by recursively subdividing the<br />
observations, through binary splits. inito<br />
subgroups based on values of variables that<br />
maximize variance reduction or minimize<br />
the predictive error of tlie depeindent vairiable.<br />
Subgroups aire designated termiiiiiinal<br />
'4
\'nKV 111,I No. 2, IIIJ·,ri<br />
- 43 -<br />
Lroups when tlhey caliirot le pautitionedil<br />
further either because the samnple sizes are .<br />
too sinall or the remaiiiuiig variation is<br />
either tio low to Ibe redticedl ltirther or iunexplainable<br />
iii teris of the variables in the<br />
data base. Each observation is contained in<br />
one and only one of these terminal groups.<br />
with a predict.ld value eqtual to thie mean of<br />
the group. That is, ifykj is the value of 'the<br />
dependent variable for thejth observation<br />
within the kth group, then<br />
Yk =- k * ek (2.1)<br />
whereYk is the mean tbr all menihers in the<br />
kth grolip und ue is thte error it: Usillg ' lo<br />
predict or estimnate Yk,. This proceldure<br />
minimizes the sulin of the (ek,)- over all<br />
observations. Thlis, individial oblservations<br />
tend to have Iv¿alules close to thle incai¡<br />
valite of tlie terminal grotup to whichl they<br />
belong.<br />
It was decited that the approach had he<br />
be implemented on an inutiractive basis to<br />
accommodate a hligh level of physician iiitervention.<br />
This was an important considleration<br />
since group formation using this<br />
algorithm is biasically iterative in niature.<br />
Since no computer system existed that<br />
could handie large data bases efficiently in<br />
the interactive mode, a new technology<br />
was developed called AUTOGRP. 20 AU-<br />
TOCRP supports a facility allowing onne to<br />
·invoke a;n algorithm that determines pirtitions<br />
hbased on the variance redluction<br />
criterion c' tée? AID algorithm. This coinmand,<br />
o¡ capability, of the system is referred<br />
to as the CLASSIFY tacility.<br />
' Mathematically, the algorithm can be<br />
'described as follows20 : Each observation in'<br />
Ia.data set has a value of the independent<br />
yariable X and a value of the dependent<br />
variable Y. lf there ;iare N possible distinict<br />
values of the independent variable, then<br />
'ihe subset of observations, or records, that<br />
'has each value X, (1 . i - N) is called a<br />
'category. If there are Mi observations in the<br />
Ith actcgryv (1 ~ i ', N), ithe toital sitan tl'<br />
squares (TSSQ) of the data with respect to<br />
DI)C (:O()NS' UCI'I()N<br />
the dependent variable is denlled as<br />
N m 1<br />
T;SSQ = (Y -Y)<br />
i=l j=l<br />
(2.2)<br />
where Yu is the value of the dependent<br />
variable for thejth ol)servation in the ith<br />
category of independent variable, and<br />
N<br />
Y = 1<br />
i .<br />
i = 1 j=1<br />
y',<br />
N<br />
i=l<br />
M, IE (2.3)<br />
or the meanis valtiue of the dependent variable<br />
in the entire data set. The data set can<br />
be partitioned on the basis of the independent<br />
variable into G groups, where<br />
each group is the uniúín of speci'ied<br />
categories. That is, we can define the mapping<br />
of categories to groups with sets Rk (1<br />
< k 1 G), such that<br />
Rk n Rk = 0,k# k'<br />
G<br />
U R = {i,2,3 .... N}><br />
k=l<br />
The "within group sium of squares"<br />
(WGSSQ) is the total of the sqluared deviations<br />
(diffe'trences) of each group's observations<br />
from the group mean with respect to<br />
the dependent variable anad cain )e expressed<br />
as<br />
.WGSSQ (k) =<br />
where<br />
i R<br />
i o Ry<br />
Mj<br />
j l<br />
(Yjj - Y,, . 1 :r k 4; C. (2.4)<br />
WGSSQ (k) = within group sum of<br />
squares for the kth group<br />
Ilk = set of a;ill ategories of the indtcpendent<br />
variable in the kth group and
" E MIX DEFINITION BY DRG<br />
Mi<br />
js1<br />
- 44 -<br />
Y )<br />
is the mean value of the dependent variable<br />
in the kth group. The total within<br />
group sunm of squares (TWGSSQ) for the G<br />
groups is the sum of the total squared deviations<br />
of each grotip's observations froin<br />
the respective groupl meian and is given by<br />
TWGSSQ (G) =<br />
G<br />
Y,,= i R<br />
i¡ Rt<br />
M1,<br />
' (Y" -- Yk,)<br />
j=!<br />
For a given independent variable, the<br />
CLASSIFY algorithm partitions observations<br />
into the particular set of groups that<br />
results in the uminimization ofTWCSSQ for<br />
a specific dependent variable. Since<br />
TWGSSQ is proportional to the variance<br />
left unexplained by the independent variable,<br />
minimization of TWGSSQ results in<br />
the miniiiiization of the unexplained variance<br />
of the data.<br />
2.3 DRG Formation from Major<br />
Diagnostic Categories<br />
To facilitate the analysis over the wide<br />
range of disease conditions in the acutecare<br />
setting all diagnoses were initially<br />
divided int.i 83 mutually exclusive and<br />
exhaustive Major Diagnostic Categories.<br />
Their formation was also motivated to insure<br />
diagnostic hornogeneity. Thus, the<br />
final clusters do not contain patients that<br />
transcended these categories. For example,<br />
from the point of view of output utilization,<br />
it may be appropriate to form a patient<br />
class with hemorrhoíds, hypertrophy of<br />
tonsils, and normal delivery. The ou" ut<br />
utilization of these patients is very similar,<br />
often ret,s.`ring a relatively minor surgic.l<br />
procedure with a very short preoperative<br />
stay and a total hospitalization period of 2<br />
1.<br />
iE Rk<br />
(2.5)<br />
MiEDICAL CAIIE<br />
or 3 days. However, the physicians who<br />
would treat these patients as well as the<br />
treatment processes of the problems they!<br />
are presenting are quite diflerent. Therefore,<br />
it was felt that including such pati.iats<br />
ill the samine class would not define a nedlically><br />
meaningthl category.<br />
The specification of the Major Diagnos.<br />
tic Categories wvas peirforíied by al coiniittee<br />
of clinicians, tollowing 3 general<br />
principles:<br />
1. Major Diagnostic Categories miust<br />
have consisteiicy ii ternus oftleira iilt(llie.<br />
phvsiop.atho>logic classificaitiotn. or in tlht.<br />
maiutier in which tlihey are cliniícally ma.iaged.<br />
2. iMaijor Diagnostic Categories ¡must<br />
have a siulicient iinuiber of patients.<br />
3. Major Diagnostic Categories mniust<br />
cover the complete range of codes withouit<br />
overlap.<br />
A list ofthese categoríes as de'ined by their<br />
ICDA8 and HICDA2 codes appears in<br />
Table 1. There is also an indication of the<br />
corresponding Professiohal Activity Study<br />
(PAS) diagnosis groups that correspondl to<br />
each category. Note that the categories are<br />
very broad, such as Diseases of the Eye.<br />
Diseases of the Cardiovascular System aud<br />
Infectious Diseases..<br />
A consistent process was followed in partitioning<br />
each Major Diagnostic CategorY<br />
into DRGs. First of all, each category was<br />
refined by eliminating certain unwanted<br />
observations. Cases with dead patients or<br />
bad records, and those that were particiularly<br />
deviant, were excitided ironi tiirIIILr'<br />
analysis. Cases with dead patients were<br />
removed trom consideration since thleir<br />
lengths of stay were probably atypical of<br />
the disease or problemni under consi(lerai<br />
tion. Records with olbviois coding errors or<br />
missing data were also eliminated because<br />
their information could be misleading. Ob-
Vol. XVIII, No. 2, Supplenent<br />
- 45 -<br />
TABLE 1. Major Diagnostic Categories<br />
DRC CONSTRUCTION<br />
Mijor PAS lIDAS HICDA2<br />
Category Initial Grotup Nainies G Crollp No. Codes (odes<br />
1 Infectious Diseases<br />
1-8, 10-17 000-0689,<br />
071-1360<br />
2<br />
3<br />
4<br />
5<br />
6<br />
Malignant Neoilasmi of Digestive System<br />
Mlalignlnt NS'eolasmi of Respirato
- 46 -<br />
CASE MIX DEFINITION BY DRG MEDICAL CARE<br />
T ILE 1. Continued.<br />
Major PAS ICDA8 tlICDA2<br />
Category Initial Group Names Croup No. Codes Codes<br />
33 Pulmonary Embolism<br />
34 Phlebitis and Trombophlebitis<br />
35 Hemorrh.dls<br />
36 Hyperér
'Vol. XVIII. No. 2, Supplemient<br />
- 47 -<br />
TABLE 1. Continued.<br />
DRG CONSTRUCTION<br />
Major PAS ICDA8 HICDA2<br />
. Category Initial Group Namies Group No. Codes Codes<br />
_: .<br />
65<br />
66<br />
67<br />
68<br />
69<br />
Dis,ases of Skin and< Suhcutanetous Tissue<br />
Arthritis<br />
Derangetnent and Displacemnent of<br />
Intervertehbnl Disc<br />
l)iseaser s of Bole anid Cartilege<br />
O)tler Diseases of Musculo-Sikeletal Systemni<br />
70 AniL:ci;i ioixiailies<br />
71 Normal iMature Born<br />
72 Certain Diseases and Conditions Peculiar<br />
to NewbSrl Il[ats<br />
73 Syniptoixis anid Signs Relterable to Nervous,<br />
lRespiratory, aa.(d Circulatory Systelns<br />
74 Symptonis and Signs Referable to GI<br />
and Urinary System<br />
75 Miscellaneous Signs, Symptoms. and<br />
Ill-defined Conditions<br />
76 Fractures<br />
77 Dislocation and Other Musculo-Skeletal<br />
Injury<br />
78 Internal Injiury of Craniumn, Chest,<br />
and Other Organs<br />
79 Open Wound and Superficial Injury<br />
80 Burn<br />
81 Conmplication of Surgical anid Medical Care<br />
82 Adverse Effects of a Certain Substance<br />
83 Sls>.-eia a l A i¡ issi>l. s :iredl IE.x;uiuliinatiolis<br />
Widiout reported Diagnosis<br />
251. 252,<br />
254-255<br />
256-258<br />
265, 266<br />
261-264<br />
259. 260. 267<br />
268-271<br />
272-282<br />
342. 343<br />
283, 344-349<br />
680-6840,<br />
686-7099<br />
710-7150<br />
725-7259<br />
7171-7180.<br />
720-7249<br />
716-7170,<br />
726-7389<br />
7.10-7433.<br />
7%138-7570,<br />
7572-7599<br />
Y20-Y209,<br />
Y22-Y239,<br />
Y26-Y279<br />
Y21-Y219.<br />
Y24-Y259,<br />
Y28-Y299.<br />
YO05, 780-7799<br />
lo<br />
284-287 4432, 780-7808,<br />
7814-7815.<br />
7817-7823,<br />
7825-7834.<br />
7836-7837<br />
288-290 784-7865<br />
291-295 606-6060,<br />
628-6280,<br />
6293. 6295,<br />
7810-7813,<br />
7816, 7835,<br />
7866-7889,<br />
790-7910,<br />
793-7969<br />
296-310 800-8299<br />
311-316 830-8480<br />
317-320, 326 850-8699,<br />
332 950-9599,<br />
9953, 9954<br />
321-325, 870-9390<br />
327-330 996-9969<br />
331 940-9499<br />
338, 339 997-9991.<br />
9993-9999<br />
333-337 960-9952,<br />
9955-9959<br />
340, 341 YOO-Y004.<br />
Y006-Y 159,<br />
379-3793,<br />
388-3899,<br />
789-7899<br />
---<br />
680-6840,<br />
686-7099<br />
710-7150<br />
725-7259<br />
7171-7180.<br />
720-7249<br />
716-7169.<br />
719-7199,<br />
726-7390<br />
740-7.599<br />
Y20-Y209.<br />
Y22-Y229<br />
Y24-Y249<br />
Y21-Y219,<br />
Y23-Y239<br />
Y25-Y299,<br />
Y40-Y489.<br />
760-7689<br />
770-7709,<br />
773-7769,<br />
778-7799<br />
780-7839<br />
771-7728,<br />
777-7779,<br />
784-7969<br />
800-8299<br />
830-8489<br />
850-8699,<br />
900-9049,<br />
950-9599<br />
870-8979,<br />
910-9391<br />
940-9498<br />
996-9999<br />
960-9959<br />
Y00-Y 1'.J<br />
Y50-Y896
CAo.. MIX DEFINITION BY DRC<br />
- 48 -<br />
servations with disproportionately high<br />
values of length of stay were excluded<br />
since a few deviant records could have a<br />
marked effect on the stability of a group's<br />
distribution. -<br />
The screened set of records in each<br />
category was then used as input to the seconcd<br />
stage, in which the CLASSIFY algorithm<br />
was applied to suggest groutps of<br />
observationls, on the basis of prespecitied<br />
incdependent variables, that may he different<br />
with regardl to length of stay. The set of<br />
independent variables selected as input to<br />
the alh~orithmil was intentionally limited to<br />
those variables descriptive of the patient,<br />
his disease condition and his treatment<br />
process that would be readily accessible on<br />
iimost discharge abstracts, specifically diagnoses,<br />
sturgical procedures, age, sex and<br />
clinical service. This constraint was<br />
applied for several reasons. First, mean<br />
lengths of stay are oblserved to vary across<br />
levels of these variables in descriptive<br />
statistical suminaries of hospital discharge<br />
data. 23 Second, these variables are always<br />
recorded and entered in almost all hospital<br />
inftrmation systems. This increases the<br />
classification's potential for implementation<br />
in most research and applied healthcare<br />
settings. Including other items of information<br />
such Ias ancillary services used<br />
would limit its applicability to those systems<br />
that collect such data, which would<br />
exclude, tor example, the PSRO PHDDS<br />
data base. Fin' ly, restricting the variables:<br />
to this set also simplifies the class definitions<br />
and controls to some extent the final<br />
.11imber of categories. A classification with<br />
numerous groups and a complex definitional<br />
structure is unmanageable. ,<br />
For each independent variable. output<br />
from the CLASSIFY procedure inltluded<br />
the total numberofobservations in the data<br />
set, the total number of different values<br />
the variable assumed (i.e., number of<br />
categorie.; ,- c:ells), the number of groups<br />
formed, the total suni of squares (TSSQ)<br />
and the per cent reduction in total sum of<br />
squares attained by such a grouping<br />
SIEDICAL CA:RF.<br />
((TSSQ-TWGSSQ) / TSSQ)* 100. Once<br />
these results were obtained, a cliniciSi,n<br />
selected the inost appropriate variablle<br />
for division.<br />
--The interpretation of the partitioning<br />
suggested by the algorithin was a comiplex<br />
task, with many fiactórs examined and<br />
weighed simnultaneouLsly. The decision to<br />
accept, to reject or possibly to revise the<br />
recomniended partitioning was based (on<br />
bothl the statistical evidelnce aind the cliíi.<br />
cian's imedical knowleclge. The statistic,,i<br />
results were examined in light of certain<br />
criteria. Variables yielding the highll(st<br />
percentage reduction in variance werc<br />
prime candidates tbr dividing the data set.<br />
However, the number ofcells or values fir<br />
those variables and the nutmber of groups<br />
tobmed were also considered. It is an artifact<br />
of the algorithmi that many partitions<br />
can be created when the independent variable<br />
has a wide range of v ilues. Moreover,<br />
too many grotups forined at the first split<br />
become difticult to manage and are of<br />
(luestionable significance. For example,<br />
secondary diagnosis often had many diifterent<br />
values and thus often produced significant<br />
variance reduction by forming<br />
many subgroups. However, such grontps<br />
were diffticult to interpret as a prinmary partition<br />
and tended to be of limited value. In<br />
all cases, groups were further examined in<br />
a more descriptive framework to determine<br />
if the statistical significance was supported<br />
by medical interpretability.<br />
The Lict that a variable that appeared to<br />
be powerful in explaining variance was not<br />
selected at a particutlar stage does not mean<br />
that the variable was ignored. Two possibilities<br />
still existed. If that variable were<br />
independent of other variables in explaini<br />
ng variance, it would appear in subl>sequent<br />
stages with the saime power as at<br />
the earlier stage. If, howéever, it were correlated<br />
with a variable 'chosen at an ealier<br />
stage. then its explainatory power at sul>selqent<br />
stages woulldl be lesscled accordling<br />
to the strength of the correlation. For<br />
example, if seconclary diagnosis WaS
?Vol. XVIII. No. 2. Sttilluleareiltte<br />
- 49 -<br />
strongly related to age and Lage was<br />
selected ats a partitioniiiig variable, thenl<br />
secon(idary diagnosis would not aippear<br />
powerful in subsequent clustering.<br />
Groups were then generated bas i on<br />
the most appropriate variable, that is, the<br />
one that .et as nainy of the criteria<br />
specified above as possible. In particular, it<br />
1) exhibited a significant reduction in variance<br />
relative to iiost ot the other variablles,<br />
2) created a manageablie ni tilher of>groil>ps<br />
based on the relatively smaill iinlmer ol<br />
values of the independeit variable, and 3)<br />
createtl groups whiose ueaiits were signilicantly<br />
dlitierent. Also. grotups Ibruied were<br />
homogeneoxns troni a clinical perspective.<br />
Once each Mlajor Diagnostic Category<br />
was initially pairtitioled inito suilgrotips<br />
based on the valiues of an independent varíable,<br />
a decision was nmade whether or not<br />
to further subdivide each saubgroup based<br />
on any of the other available variables or to<br />
end the partitioning process by treating<br />
thenm as terminal groups. The statistical<br />
basis for this decision was deterniined by a<br />
set of stopping r ules. For any given gronup,<br />
the partitioning ceased when etiher one of<br />
the following conditions was mnet:<br />
1. The grrotip was not large enoughl to<br />
Warrunt anIother classificatiom, tlhat is, whllvl<br />
the ilnliilber of oihserfiltion>is in the groiup<br />
was less thani 100.<br />
2. None of the varialbles relducedl uniexplainil<br />
variation I)v at Ieast 1%, or<br />
((TSS -'I WSSQ)/TSSQ)*100 < 1 per<br />
cent.*<br />
Otherwise, the group was fuirther subdivided<br />
according to the criteria discuissed<br />
previously tor generating new, sulbgroups.<br />
In some cases, however, the process was<br />
terminated tor nonstatistical reasons regarding<br />
overall inanageability (e.g. inaintaining<br />
a low number of total groups) or<br />
medical interpretability.<br />
* This I per cent I>ouid was increased ii certain<br />
Major Diagnostic Categories.<br />
DC; :()NST'I'(:'i'ION<br />
Tlhis grotu),ping process resulted i¡ tihe<br />
lormatio, oí' :383 finai grolups or I)CG.s<br />
each defutied by somie set of the tollowing<br />
patient attributes: primary diagnosis, see-<br />
' ondiny diagnosis, primary surgical procedure.<br />
secontlary surgical procedure, age,<br />
and in one case, clinical service aiea. While<br />
other variables such as sex, tertiary diagnosis<br />
or surgical procediure were<br />
examtined, they were not imnild to be significiant<br />
iii explaining ouitput utilization. A list<br />
of these grotups with a brieft narrative descriptioei<br />
of their contents appears in the<br />
Ap)l)elctlix. A more ctiip)lete spetcification<br />
can be obtained fromn tlie Health Care<br />
Financing Administration.'<br />
The DRGs vary considerably in their<br />
structure across the iMajor Diagnostic<br />
Categories. Some Major Diagnostic<br />
Categories are not further subdivided,<br />
such as Category 35, Hemorrhoids, in which<br />
no variable demonistraited a sufficient efttct<br />
in further explaining outpitt uti lization. On<br />
the other hand, Appendicitis, Category 46,<br />
is ftirther subdivided on, the basis of<br />
specific primary diagnosis and the presence<br />
ot a secondary diagnosis. This restilts<br />
in 4 DRGs: appendivitis (without<br />
peritontitis) and without a secondary diagnosis,<br />
appendicitis (without peritonitis)<br />
with a secoudary diagnosis, appeidicitis<br />
(with peritonitis) without a secondary<br />
diagnosis, and appendicitis (with<br />
peritonitis) with a secondary diagnosis.<br />
This symmetric breakdown suggests that<br />
the effects of primary. diagnosis and the<br />
presence of a seconldary diagnosis are additive<br />
in nature. Major Diagnostic Category<br />
76, Fractures, has the nmost complex structure,<br />
resulting in 13 DRGs, indicating both<br />
the importance and interaction of 4 variables:<br />
primary diagnosis, secondary diagnosis,<br />
prinmary surgical procedure and age.<br />
It should also be noted that when variables<br />
are h.ghly correlated, very often only<br />
one applears in the classification for a<br />
specilic mnajor category. Asn extrieme exampie<br />
of this is Major Diagnostic Category 36,<br />
Hypertrophy of Tonsils aud AdeMoid,
- 50 -<br />
( ASE MIX DEFINITION BY DRC NIEDICAL Ckax<br />
Fic. 1. Tree diagram i!lustrating partitioning of urinary calculus patients.<br />
where almost everyone has a tonsillectomy<br />
anid/or an adenoidectomy. The high correlation<br />
of primary surgical procedure with<br />
primnary diagnosis results in no further variance<br />
reduction in the category that can be<br />
attributed to surgical procedures. Thus, although<br />
stirgery is aiinost always used in the<br />
treatmneit e.' i.,';esits with Hypertrophy of<br />
Tonsils anacl Adenoíds, since virtually<br />
every patient in this category had the same<br />
surgical procedure, the surgical information<br />
did not differentiate the utilization of<br />
these patients and was therefore not used<br />
in the formation of the DRGs for this<br />
category.<br />
2.4 An Example<br />
The iterative partitioning process used<br />
in form;,-. the DRCs can hest be illustratedl<br />
ti¡ tic co.ltext ol aln xamill)lc-tile<br />
classitication of lMajor Diagnostic Category<br />
55: Urinary Calculus. This category con-<br />
tains patients with a primary diagnosis<br />
(ICDA8 codes) of either 592, calculus of<br />
kidney and ureter, or 594, calculus of other<br />
parts of the urinary system. The formation<br />
of the DRGs from this Major Diagnostic<br />
Category is summarized in the tree diagram<br />
presented in Figure 1. First, this<br />
category is partitioned into 3 groups based<br />
on the variable primary surgical procedure.<br />
The first group contains; nonsurgical patients,<br />
which are those with either no operation<br />
or with a procedure code (ICDA8)<br />
outside the range 010-999, A10-A59,t The<br />
second and third groupsare fonned on the<br />
basis of the specific procedure perfonrned.<br />
In particular, the imore complicated procedures<br />
perfonned on patients with a urinary<br />
calculus-ne.phrotomy, ureterotomy,<br />
cystotomy-are in the third group, while<br />
f Operatitións oed outside these ranges ae not<br />
considered actual surgicil procedures since they<br />
represent minor procedures or therapies.
.'yo. XVIII. No. 2, Supplentcsit<br />
Size = 1125<br />
- 51 -<br />
DRG CONSTRRUCTION<br />
TAtiLE 2. Descriptive Stastistics tor the Partitioning of<br />
MIajor I)iaganostic Category 55 (Urinary Calculis).<br />
Mean '-= 6.93 S.P. - 6.44<br />
Partial M .Mean<br />
:' Independent Variance Length<br />
Variabhles Explainiiedl DRG No. Size lf Stay S.D.<br />
Priinary surgery<br />
. Minor<br />
Major<br />
Seconidary tLi.glo
- 52 -<br />
CAS¿ MIX DEFINITION BY DRG MEDICAL CkAE<br />
TABLE 4. Suggested Partitioning (3 groups) of Urinary Calculus<br />
Paticnits on tie Basis of Typ)e ofI Priiialry Surgery<br />
Independent<br />
Group Size Mean ' Vtiable Description<br />
I 1 2.00 749 Other antepartmn procedulres to<br />
ltrminate pregnancy<br />
1 2.00 571 Mleatotomy<br />
1<br />
1<br />
1<br />
1<br />
2.00<br />
2.t00<br />
3.00<br />
3.(X)<br />
277<br />
249<br />
430<br />
862<br />
Venous anastoinosis, intra-abdominal<br />
Other opr:ationis on peril)heri vessels<br />
Incision of bile (hepatic) ducts<br />
Arthrocentesis<br />
1 :3.00 601 V;asectomy<br />
1 3.00 921 Local excision of lesion of skin<br />
adii siilcittaiiteons tissie<br />
2:) 3.28 (000 No code<br />
688<br />
1<br />
4.08<br />
5.00 551<br />
No code<br />
Ureterectomny<br />
2 2 5.50 574 Repair and plastic operations<br />
on nrethra<br />
7 5.71 559 Other operationls on ureter<br />
218 6.25 A46 Cystoscopy and irethroscopy without<br />
effect upon tissue<br />
5 6.40 A45 Endloscopy of colon and rectum without<br />
eifelct upon tissue<br />
la 6.40 568 emioval of calculs aLnd drainage of<br />
bladder withoot inicision<br />
2 6.50 57'2 Excision or destruction of lesion<br />
of nrethra<br />
146 '6.59 557 Passage of catheter to kidliey<br />
21 7.14 575 Iilation of urethra<br />
1 9.00 A16 Biopsy of thorax<br />
3 2<br />
2<br />
1<br />
1<br />
10.00<br />
11.50<br />
12.00<br />
13.00<br />
A21<br />
566<br />
A44<br />
549<br />
Biopsy (contined) oF turinary tract<br />
Repair an.d other plastic operations<br />
on hladder<br />
Esophlagoscopy and gastroscopy without<br />
el'fect ipon tissue<br />
Other operations on kidney<br />
1<br />
, 3<br />
13.00<br />
13.67<br />
14.00<br />
556<br />
561<br />
562<br />
...<br />
Repair and plastic operations on ureter<br />
Local excisiot antd'estruction lesion '<br />
of bladder, transurethrol<br />
Local excision and destruction of<br />
lesion of bladder. otihbr<br />
3 14.00 582 Prostatectomy, transurethral<br />
1 14.00 583 ~<br />
Prostatectonmy, other<br />
8 14.13 545 ,Nephrectomy, complete<br />
72 14.46 541 Pyelotomy<br />
40 14.47 560 Cystototomy<br />
101 14.63 550 Ureterotomy<br />
19 15.89 540 -Nephmtomy<br />
1 16.00 513 : : eiieorrhoidectoiny<br />
11 16.82 544 Nephrectomy, partial<br />
1 17.)00 546 Repalir anid plastic operations<br />
on kidney<br />
570 Urethrotomy, external<br />
1 21.00 A27 Biiopsy of hone<br />
I.(1. 5
.V'oL XVIII. No. 2. Stpphlidary diagnosis<br />
(tLx), age, auid sex.<br />
The number of groups formed by the<br />
algorithm and the corresponding per cent<br />
reduction i¡n unexplained variation tbr each<br />
of the ,ai-'lttles are shown iii Tablle 3.<br />
Sinc- the greatest reduction in unexplained<br />
*ariation was achieved with operl,<br />
and a linited mnhuher *of gr'oups (3) this<br />
variaulle wvas considered thle prilne *- "ilidate<br />
for initial subdivision of the caitegory.<br />
The algorithli suggested 3 groups whose<br />
vontetlns are described inl Tabl 'l e . This<br />
table presetits the diillerent :;urgical procedures<br />
contained in each groutp, the<br />
corresponding number of observations<br />
(SIZE), and the meait lengthi of stay<br />
(MEAN). Note that Inorkt thal .98 per cent<br />
of the obseraitions il tlihe tirst rtrollp have<br />
no surgical procedure listed. The second<br />
grotlp primarily contails ol>servationis with<br />
relative!y mitior procedtres such as cystoscopy<br />
a;i¡
CASE MIX DEFINITION BY DIIC<br />
'ABLE 7.<br />
No.<br />
Group Observed Mlean S.D.<br />
No secondary 449 3.28 2.88<br />
Secon
Vol..'XVlII, No. 2, Supplement<br />
- 55 -<br />
All uWlW C~oi/i<br />
· 1425<br />
0 4 9 Iz b 20 24 26 2<br />
*imgfh ot #tey l{dr y<br />
lAqjlí of soy {6ays)<br />
No Surwqry Mtno Suqi.es to uol Su;oo.s<br />
n ?.71 ·<br />
A 429 A ' 286<br />
m.oen 403 mon<br />
4 · 33<br />
4 430 * . 31<br />
e 636 mon * i499<br />
4Vf'(<br />
DRC CONSTRUCTION<br />
o a te iC 20 24 2? {2<br />
iingth of s1ay (dura)<br />
04 a 2 6 s 2G 24 e# 32<br />
loeth of * ¡oy dop.)<br />
0 4 a 12 4 20 24 2e 32<br />
tength of fey (O40<br />
DOR 241<br />
C.»u , f.. C$oqIC. t<br />
DO0,or i20 00ot41w 01 COAu ¡Ow lo loW0 h)0.<br />
1<br />
.<br />
0*G 242<br />
¡loddO CO4....u s tl<br />
n~ "t-~, CAt100. ¡oy,00*2.<br />
O]~,o<br />
8¡8 beOn<br />
o1 o~4·1K~ _ o4 4t<br />
P dM SGo avy<br />
0 4 t2 4 2024 2 32<br />
IwgiN of etoy id~r)<br />
Wdns o l Pe____,__t I ____oD P _oera<br />
W*lhu!n S.o4dr Da Wth S~odwr Oi<br />
| r * 449 r * 262<br />
_-I I * · 329~ meao ·632<br />
04 e I* 20 2429 232 4 6 12 4 20 24 2 32<br />
lengAQ of oM (¡do1o) eng *o~y of l4(dOyl<br />
006 230 11 I :0¡<br />
wemi Co¡sw, u e a.., *.tq¡ eOoo<br />
.4 '..OO Su m uan r<br />
.i Con .o tee , tOlgl ,<br />
y o s~orib o oup i<br />
FIc. 2. Sunimary of lerngth-of-stay distributions for groups fortmed in partitioning provess.
C- ' MIX DEFINITION BY DRG<br />
TABLE 11.<br />
- 56 -<br />
No. of Per Cent<br />
Variable Groups Reductiba<br />
age 3 1 ..05<br />
oper2 1 0.0<br />
dxl 1 0.0<br />
%ex I 0.0<br />
down ofthe surgical groups on the basis of<br />
secondary diagnosis. Moreover, in light of<br />
one of the major objectives of' keeping the<br />
total number of classes low, additional<br />
groups formed at this stage of the partitioning<br />
of Urinary Calcultus patients would be<br />
of questionable value. Therefore, the 2<br />
surgical grotups were not divided further<br />
but were considered terminal groups.<br />
Step 5<br />
The 2 subgroups formed from the nonsurgical<br />
cases on the basis of presence or<br />
absence ofother díagnoses were evaluated<br />
to determine if they should be partitioned<br />
further or left intact as terminal groups.<br />
The algorithm was applied and produced<br />
the results shown for the nonsurgical cases<br />
without multiple diagnoses. The algorithm<br />
produced the results listed in Table 11 for<br />
the nonsurgical cases with multiple<br />
diagnoses.<br />
With respect to the nonsurgical cases<br />
without multiple diagnoses, both sets of<br />
groups font - - ,n the basis of age and secondary<br />
sa ,ncal procedure, respectively,<br />
MEDICAL CARE<br />
were determined unacceptable. In each<br />
instance, more than 95 per cent of the ob.<br />
pervations fell into the first group, leaving<br />
the second group with fewer than 25 cases.<br />
For the nonsurgical cases with multiple<br />
diagnoses, the 3 groups formed using age<br />
levels were considered as potential sub..<br />
groups. The age levels detining the bound.<br />
aries of the groups were 66 and 70. This<br />
partition was rejected for reasons similar to<br />
those above, namely, the lopsided distribution<br />
ofl cases in thle groups. Almost 90 per<br />
cent of the observations had an age under<br />
66.<br />
Thus, the nonsurgical groulps with aind<br />
without multiple diagnoses were consíidered<br />
terminal groups.<br />
We conclude, then, that specific surgical<br />
procedures and the presence of multiple<br />
diagnoses were ímportant variables in<br />
predictir.g length of stay for urinary calculus<br />
patients. The 4 DRGs formed were<br />
significantly different (a = 0.01) with respect<br />
to their average lengths of stay and<br />
are clinically interpretable. To be sure, by<br />
overruling some ofthe partitions suggested<br />
by the algorithin, a certain anmoulnt of<br />
explanatory power was sacrificed. But, the<br />
trade-off was generating a reasonable<br />
number of subgroups or DRGs which<br />
could be interpreted from a medical<br />
perspective. Figure 2 presents a descriptive<br />
summary ofthe length-of-stay distributions<br />
for the groups formed as part of the<br />
partitioning process in this example.
- 57 -<br />
MEDICAL CARE<br />
Febiuary 1980, Vol. XVIII, No. 2. Supplemteilnt<br />
3. Interpretation of the DRGs in Health-Care Studies<br />
THE DRGs AS CONSTRUCTED met the original<br />
rese:trch objectives; that is, they provide<br />
a detinition of case types by relative<br />
output ::tilization, where the definition of<br />
case type ¿has the fillowing properties:<br />
1. The varialbles iste in ti the deinition ol<br />
a case are li¡¡¡ited( t tthose reflirring to the<br />
patient's ;at ilre 'tiillilllll
CA .IIX DEFINITION BY DRG<br />
- 58 -<br />
differences among providers still remain<br />
with respect to length of stay and other<br />
output mneasures which cannot be accounted<br />
for by patient characteristics ora.<br />
surgical procedures.<br />
The development of the patient classes<br />
is not intended to inhibit in any way the<br />
practice of medicine but to offer one the<br />
capability of examining reasons for variations<br />
in service utilization, treatinent provess,<br />
and outcomie. In this cont..dt, the<br />
groups can provide a iramnework tor the<br />
initiation of an ongoing process of comparative<br />
anialysis of hlicatlh caire with the<br />
long-rim goal of determining both the cost<br />
and value of any kind of care that might be<br />
delivered. With such information, meaningful<br />
dialogue among clinicians, administrators,<br />
planners and regulators canl proceed<br />
in rationalizing of observed difterences.<br />
Only in this way can strategy, policy and<br />
ME :DICAL CAR:<br />
politics interact to the benefit of the con,.<br />
munities served by each institution.<br />
The classification of patient records into<br />
DRGs is a constantly evolving process. In<br />
fact, the group structure described here<br />
represents the third classification schelie<br />
developed using the methodology pre.<br />
sented in the previous section. As coding<br />
schemes change and data are collected thiat<br />
are more current and represelntativei o'<br />
acute-care institutions in the United States.<br />
these grotps will be re-examined anud revised<br />
accordingly.<br />
Clinently the DRCs arc being appllied in<br />
a number of different practical and research<br />
settings in the health-care field.<br />
While these applications are discussed extensively<br />
elsewhere, a brief overview is<br />
presented in the following sections to give<br />
the reader a better uinderstanding of the<br />
DRGs' potential utility in a variety of areas.
- 59 -<br />
.SlDiCL ( :AL..<br />
FcbnartlrJ pI
CASE ' : DEFINITION BY DRG<br />
. Gcc<br />
tx.<br />
Lz .<br />
x<br />
14WW<br />
oEc.v<br />
w cn<br />
U-.<br />
<<br />
-Isa<br />
W Z<br />
X :<br />
, a<br />
o<br />
x<br />
-<br />
u '<br />
-aM.<br />
<<br />
1 1<br />
¡ 1<br />
cn -1 r- 01<br />
- ~ .'<br />
- i--- -<br />
04<br />
~ r-cae-u(E ~<br />
r- a a -c c c '<br />
'-04et .qIl ca -ca<br />
- 60 -<br />
ci<br />
a<br />
o<br />
1<br />
oe<br />
9-<br />
u<br />
MIEDICAL CARe<br />
number of bed days consumed per dis.<br />
charge. A case mix-adjusted length of stay<br />
(CASE MIX ADJUSTED LOS) appears íu<br />
.colunin 4 and is the mean length of stay the<br />
hospital would have experienced with the<br />
region's case mix. For the ith hospital, it is<br />
computed as<br />
j<br />
J PJ j= 1,.... -383 (DRG) (4.1)<br />
where au is the average stay in thejth DRC<br />
in hospital i, and Pj is the proportion of the<br />
region's cases i¡i )RG j. As such, it stamil.<br />
ardizes or holds constantcase mix across all<br />
institutions and results in a measure that<br />
one can use to compare hospital utilization<br />
based oa length of stay.<br />
As a complement to the case mixadjusted<br />
length of stay, column 5 contains<br />
the average length of stay the hospital<br />
would have experiencgld with its owtn catse<br />
mix, but the region's average length of<br />
stay within each of the DRGs (LOS<br />
WEIGHTED CASE MIX). That is, for the<br />
ith hospital it is computed as<br />
A p, j = ....,383 (DRG) (4.2)<br />
where AN is the region's average stay in the<br />
jth DRG, and pu is the proportion of the íth<br />
hospita's cases in thejth DRG. Since it uses<br />
a standard set of relative weights (Aj) ftr the<br />
DRGs, it can be interpreted as a relative<br />
measure of case mix complexity, with<br />
higher values indicating a more complex<br />
case mix, that is, a greater proportion of<br />
cases receiving a high amount ofthe hospital<br />
outputs. In interpreting this measure, it<br />
should be noted that complexity is a function<br />
of both the condition of patients as<br />
well as the treatment process selected by<br />
physicians. Columns 6 through 8 are indices<br />
computed by dividing the measures in<br />
columns 3 through 5, respectively, by tlhe<br />
region's average length of stay.<br />
Columns 9 through 12 present the observed<br />
difference between the institution's
Vol. XVIII, No. 2, Suppletiment<br />
- 61 -<br />
and region's average length of stay (AV.<br />
ERBAGE LOS DIFFER) and indlicate to<br />
what extent this dit'ference can be attributed<br />
to DRG-specific average length of<br />
stay or the ai (DIFFER DUE TO LOS), the<br />
case mix of its patients or the PU (DIFFER<br />
DUE TC CASE MIX), and the combination<br />
of the 2 or their interaction (INTER-<br />
ACT DIFFER).<br />
The separation ot' the diltereiice intO<br />
these comiponents is hased ou the<br />
technique described by Kitagawa,'4 brietly<br />
dlescribed here fi)r the reader's convenlience.<br />
It' ; auld A reprepresent tie averalige<br />
length of stay for the ¿th iistitution and the<br />
region, respectively, then<br />
a, = Pj aJ;, = 1 .... 33 (DRGC) (4.3)<br />
A = PJAJ. j = ..... 383 (DRG) (4.4)<br />
The difference between a; and A can be<br />
expressed as<br />
DRGC APPLICATIONS<br />
hospital and the region not accounted for<br />
hy the LOS difference (column 10) or the<br />
case mix difference (columnn 11).<br />
The utilization of the report lies in interpreting<br />
the differences observed between<br />
an indivtdual institution and the set of institutions<br />
or region as a whole. For example,<br />
consider Hospital 4, the largest with<br />
41,643 cases (column 2). Its average length<br />
of stay was one of the longest, 7.479 days<br />
(column 3) or 0.708 days longer than the<br />
region (column 9). This diftterence can be<br />
attribhltedl in varying degrees to the following<br />
componients: 1) dileretices iii case<br />
composition or case mix; 2) differences in<br />
case-specific average lengths of stay; and 3)<br />
differences attributed to the interaction of<br />
case mix and case-specific average lengths<br />
of stay. With respect to the first component,<br />
if the hospital's case mix had been treated<br />
at the region's average length of stay per<br />
DRG, Hospitail 4's average length of stay<br />
would have been 6.96 days (column 5), for<br />
a difference of 0. 188 days over the region<br />
(column 11). On the other hand, if the case<br />
a - A = P (a, -A,)+ Aj (p - P) + (a - A (p - P<br />
AVERAGE<br />
LOS<br />
DIFFER<br />
,,., j , . / . -<br />
DIFFER DUE<br />
TO LOS<br />
for i = 1 .. , 383 (DRG).<br />
I'This .may be rewritten as<br />
DIFFER DUE<br />
TO CASE<br />
MIX<br />
k-A=( A Pa",,- PA,)+ (1 Ap p,,- A, P) + C (aU-) (pi,-P,) (4.6)<br />
.'i j j j J<br />
for j = ,...,383 (DRG),<br />
.from which we note that the first 3 differ-<br />
1:ences are computed by subtracting the<br />
region's average length of stay from the<br />
m,,,ores in columnis 3 through 5. The<br />
interaction component is the residual or<br />
the amount of the difference between the<br />
qr~<br />
INTERACT<br />
DIFFER<br />
(4.5)<br />
mix were standardized or all institutions<br />
were treating the same types of patients,<br />
Hospital 4 would have had an average<br />
lengtlh of' stay of 7.320 days (coluann 4),<br />
about a half day (column 10) longer than<br />
the region. Moreover, relative to the
CASE MIX DEFINITION BY DRG<br />
- 62 -<br />
others, it would have had the longest<br />
length of stay. Thus, institution 4 has an<br />
average stay that is .708 days longer than<br />
the region; .188 days is attributed to a more<br />
complex case mix and .548 days to longer<br />
DRG-specific average lengths of stay.<br />
The sign and magniitude of the interaction<br />
ditterence (column 12) is ani indication<br />
of the extent to ,-which the observed difference<br />
between an institution's and the region's<br />
average length of stay is accouinted<br />
tor b)y I)oth case mix and DRC-speciftic<br />
length of stay patterns jointly. It is that<br />
amount of the overall difference between<br />
tlhe iinstitutio>iial aud regional averaige.s tlhat<br />
cannot be allocated independently to case<br />
mix or DRG-specific utilization. A large<br />
positive interaction might arise, for example,<br />
if the hospital has ani average length of<br />
stay higher than the region in those DRGs<br />
where it treats proportionately more patients<br />
than the region or a lower-thanaverage<br />
length of stay in those DRGs with<br />
proportionately less discliarges. In this instance,<br />
the particular patterns of the hospital's<br />
deviation from the region in both case<br />
mix and utilization hby DRG contibuted to it<br />
having a higher average length of stay.<br />
The interaction difference is especially<br />
imniportant to consider if its absolute value is<br />
large relative to the other differences<br />
(coluirins 10 and 11). Under these circumstances,<br />
one should not use the measures<br />
in the report for that hospitalin comparison<br />
to the'others. A large interaction<br />
indicates that '>osital utilization patterns<br />
vary by cse type and standardization<br />
would be misleading. Referring to the in-<br />
.N.mriation in Table 12 Hospital 4 has a<br />
small-magnitude negative interaction<br />
component, -. 029. On the other hand,<br />
consider Hospital 8. with an average<br />
length of stay of 4.943 days or 1.828 days<br />
shorter than the region. The bulk of this<br />
difference is attributed to lower DRGspecific<br />
utilization (- 1.315 cdays), but also<br />
to -' less .. ""'niex ca;e mix (-.986). '4owever,<br />
¡note tlihat these legative diti2rences<br />
MEDICAL CARE<br />
are partially offset by a half day (.473 days)<br />
attributed to the interaction of case mix and<br />
.pertrnnance. In this instance, because of<br />
the Ml1atively large interaction term, one<br />
should exercise caution in comparing this<br />
institution's standardized utilization<br />
measures with the other hospitals in the<br />
report.<br />
Sinice discharge information on all patients<br />
is routinely collectecl by institutions<br />
fir admlinistrative puriposes, ceisus data of<br />
complete coui1ts rather than sanmples are<br />
generally available for the report described<br />
above. However, hecause of its size or limitations<br />
ina thlie imbiler of services aicl stall'<br />
available, an individual institution may not<br />
treat patients representing a large range of<br />
cases or DRGs. In this instance or in situations<br />
where there is known to be lar..e interaction,<br />
as discussed in the prec'-ding<br />
paragraph, an alternative st¡ategy is to restrictone's<br />
comparison to a limited number<br />
of institutions with uniformly high nunm-<br />
!lers of cases or to perfornm comliparisonis on<br />
a limited set of DRGs, for example, those<br />
contained in a few Major Diagnostic<br />
Categories of particular interest.<br />
4.3 Institutional and Practitioner<br />
Profiles in PSRO Evaluations<br />
Protessional Standards Review Organizations<br />
(PSROs) were ruandated under an<br />
amendment to the Social Security Act of<br />
1972 to assure the quality and appropriateness<br />
of health-care services delivered to<br />
federally funded patients (Medicare,<br />
Medicaid, Title V). To this end, one<br />
$pecific responsibility of each organization<br />
iis "profile analysis"-that is, the construction<br />
and review of relevant sunmmuries of<br />
aggregated data pertaining to the care and<br />
servwves received hy patients and provided<br />
by practitioners and institutions in the<br />
PSRO area. It is basicálly a descriptive<br />
ainalysis of health care aind service patternis<br />
uIsiug mIeastires aud lorniats which serve to
Vol. XVIII, No. 2, Supplenwt<br />
- 63 -<br />
DRG APPLICATIONS<br />
1) facilitate the identification of excep- periniented with the uise of institutional<br />
tionill areas of p)erlorinilnce and 2) Irovide length-of-stay profiles based on DRGs for<br />
a muechanismi of the ougoing miuonitoring of<br />
the overall systenm, with particuilar atten-<br />
the retrospective inonitoring oft' utilization<br />
patterns in their area.<br />
tion to previously defined prol)len areas.<br />
While ,'onsiderablle latittlde is given the<br />
PSRO ftir the tormant ainid content of'a profile,<br />
th,:re are 3 basic conmponents to its<br />
design: 1) the patient groulp, which defines<br />
the sope of tihe proille i terins o" tihe<br />
popuilattiolu to I)e aialyzed; 2) the profile<br />
subjects, which detine the subset of the<br />
patient gmroip whose data is to be profiled;<br />
that is, aggregated a,'(,l :;linallilrizc, the standard<br />
deviation (S.D.) and the median (ME-<br />
DIAN) length of stay, or 50th perc'mntile. In<br />
this example, the median length of stay for<br />
the region as a whole was 2 weeks. However,<br />
there was considerable. variation<br />
amog hospitalospitals. Hosital 8 had a m¡edian<br />
length oft'stay of 10 days, while Hospitals 4,<br />
2 antd 3 had medians of 15 days. Further<br />
investigatipn in this area through medical<br />
care evaluatian studies may be warranted<br />
to determinine if there are quality-oftcare<br />
problems in the short-length-of.stays hospital<br />
or inappropriate utilization i¡n the<br />
other 3 institutions.<br />
As illustrated i¡t the albove exaumple,<br />
these profiles are potentially useful in<br />
identifvilng areas of' inail)pro)priate utilization,<br />
which can lead to addtlitioimal issues to<br />
adl
C... L MIX DEFINITION BY DRG<br />
a<br />
w<br />
-),<br />
M.<br />
a<br />
9<br />
CL u,,,<br />
£e.<br />
ui.<br />
g.<br />
a<br />
ir<br />
;t<br />
g-<br />
«.;........<br />
wJ^Ajijijj<br />
r__l.^Omq^Wfw<br />
l*<br />
. _<br />
4* *<br />
I 0<br />
* e<br />
5 o<br />
1 e<br />
o e<br />
e e<br />
e ¡<br />
Ot tO<br />
e e<br />
t e<br />
· (<br />
um i<br />
ow<br />
, vX<br />
ee o · III I ;<br />
e:;;1-:<br />
ce1 1 1<br />
@ I *- @ I *<br />
I1* 111 I<br />
.<br />
I I I<br />
· rII111<br />
o e<br />
*e<br />
e.,<br />
I Ie<br />
aer<br />
:<br />
0<br />
* -<br />
-a<br />
·~ a<br />
a ^ a "@@wj*<br />
,,,~,,,i:? }<br />
tli ·<br />
*,' ,ri iIl<br />
I·~~~~~~~<br />
e e<br />
e<br />
e* - ~-e P~P,-<br />
--- o____<br />
__ _____<br />
--- a-----<br />
L&L O o Po<br />
rSci « .X;a;lll)<br />
o<br />
-1u ewa<br />
c<br />
Qu<br />
t<br />
e.<br />
'<br />
eV.<br />
u -<br />
z<br />
a<br />
r<br />
1c<br />
w<br />
#m<br />
u,<br />
u<br />
. u<br />
zu,.<br />
a<br />
g<br />
u' 10<br />
so'<br />
-<br />
zaM<br />
o" ,.<br />
C-9 .<br />
4a<br />
oz5Call<br />
1.4<br />
za<br />
- 64 -<br />
M1EDICAL CAIE<br />
sons. Moreover, each group can be revieweld<br />
by PSRO personiiel anid a sit<br />
selected for follow-up analyses. To tacili-.<br />
tate further the identification of aberrant<br />
utijization behavior, automnated screens<br />
based on statistical algorithmns have also<br />
been implemented that first flag those<br />
DRGs with relatively high inter-losipital<br />
v;riation, then determine for each hospital<br />
the groups in which its mean length ofastav<br />
was significantly higher than the area aidl(<br />
those in which it was significantly lower.<br />
4.4 A PSRO Monitoring Systecn<br />
The utility of the DRGs in reviewing<br />
PSRO data has suggested their potential<br />
future application as a control mnechanismii<br />
to replace the present costly concurrent review<br />
process with a timely, cost-effective<br />
retrospective monitoring systein. In this<br />
context, at the ti mne of patient dlischarge, ani<br />
abstract is produced l,and ia DRG nulnber<br />
assigned based on data in the record. When<br />
a small sample of records has accumulated<br />
in a DRG for an institution or set of i nstitutions<br />
under examinatiot., information froin<br />
the sample can be used to estimate the<br />
parameters ofthe distributions of 1 or morc<br />
dependent variables related to utilization<br />
or quality of care (e.g., length of stay, death<br />
rate, postoperative wound intection rate).<br />
Once acceptable patterns of practice have<br />
Ibeen established, thie dionitoring systenm<br />
can use standard statistical control procedures<br />
to detect changes in the process.<br />
iWhen: changes are detected, special<br />
studies may be justifie, to determine the<br />
cause for the change, which may be attributed<br />
to errors in the record, 1 or more<br />
particularly deviant cases, or an overall<br />
change in the treatment process that has<br />
affected all the cases. Work is currently<br />
under way to develop computer-based systems<br />
which could support such a control<br />
mechanism in a timely manner on either a<br />
hospital or PSRO level.<br />
.
- 65 -<br />
£.¡EDCAL CARE<br />
ebrNuarV 1;980. Vol. .YVIII. No. 2, Supplement<br />
5. Case Mix Accounting in Hospital Budgeting,<br />
Cost Control and Prospective Reimbursement<br />
5.1 Case Mix Accounting<br />
.;N NItMPt .TANT OBJECTIVE of hospital costing<br />
and budgetary systems is the uinder-<br />
·standing anct control of hospital costs. In<br />
traditional organizational setti ngs, cost<br />
control is miost su¡cccssllI ill those sitiations<br />
where well-e a<br />
precise definition of the services provided<br />
:by the institution. In a general sense, hospitais<br />
provide "patient care, .lbut more<br />
'specifically, they proviíde patient care of'<br />
.various kinds and intensities over various<br />
"durations based on the needs of the pa-<br />
.tients treated.<br />
Since the DRGs form a classification of<br />
;the patient population into classes with<br />
*!similar expected output utilization, they<br />
can provide a definíition of the services<br />
Yiprov.<br />
'w:k )y a hospital. As such, they allow<br />
t.he .esources consumed and costs incurred<br />
;to be related directly to the types of patients<br />
or case mix that the hospital<br />
t'eats. 2 .8.B This is important in a hospital<br />
setting, where it is not manageinent (i.e.,<br />
administrators) but rather individual<br />
physicians who are reasponsible tor allocating<br />
resources through various services<br />
mnd departments in order to provide effec-<br />
:tive patient care. To a large extent, physi-<br />
.*cians act independently of each other and<br />
Yj'Ure not generally aware of tihe overall lib'nancial<br />
implicatioxis oi their individual de-<br />
`isio~t. If hospital cost control is to be attaineld,<br />
effective communication between<br />
the financial systems of the hospital and its<br />
phys-cians must be achieved. By tobnulatitg<br />
the hospital biudget in terms of patient<br />
classes with similar piatterns of care. a direct<br />
linkage hetweenx the practices ot' inividual<br />
physiciians and the finaincial conseqcuences<br />
for the hospital can be realized.<br />
'rie goal, theni, of a caise mix amc:ounting<br />
systemi is to provide a complete tfinancial<br />
picture of the costs of treating specific<br />
types of patients, whose care is the basic<br />
service ofa hospital. Under the traditional<br />
organizational structure of a hospital, there<br />
is no department whose responsibility is to<br />
insure that individuial patients are financially<br />
well managed. Typically, the hospital's<br />
2 accounting systemns-linancial and<br />
managerial- deal with patients in the<br />
aggregate and not on an individual basis.<br />
The financial system provides the lbasic financial<br />
description of the hospital in ternms<br />
of the balance sheet, income statement and<br />
ftinds flow, while the managerial accounting<br />
system provides the financial information<br />
oriented at the department level (e.g.<br />
nursing, laboratory, medical records) for<br />
internal nmnagement purposes. Thus,<br />
hospitil accounting systems have not provided<br />
the integrated picture of the financial<br />
consequences of the care delivered to<br />
individual patients that case mix accounting<br />
is designed to produce.<br />
5.2 DRG Cost Model<br />
The process of determining the cost of<br />
treating patients in each of the DRGs for an<br />
individual hospital or collection of hospitals<br />
is decribed elsewhere.? In summary,<br />
the types of accounts in a hospital chart of<br />
accounts can be categorized into 6 distinct<br />
service areas: 1) outpatient accounts; 2)
CASE .MIX DEFINITION BY DRG<br />
- 66 -<br />
overhead accoulnts lnot related to piatienit<br />
care; 3) overhead accoumits related to patient<br />
care; 4) hotel and other general services<br />
accounts; 5) nursing accounts; and 6)<br />
ancillary services accounts.<br />
The DRGs currendy encompass otly tbhinpatient<br />
population; hospital outpatient<br />
costs are not included in the DRGs' costs.<br />
Overhead accounits are costs incurred I)y<br />
the hospital iii its general operation but are<br />
either not related or only indirectly related<br />
to the provision of patient care. Depreciation<br />
and interest cliarges are examiiiples of<br />
overhead costs that are not related to patient<br />
care and therefore are not normally<br />
included in the DRG costs. Other overhead<br />
accounts such as hotisekeel>ing or<br />
laundry are indirectly related to the provision<br />
of patient care and are included in the<br />
DRG cost. The definition of the overhead<br />
accolnts that are considered as patientcaire-related<br />
versus non-patient-carerelated<br />
can vary, depending on the goal of<br />
the case mix accontiting system. For<br />
strictly internal mianageinent purposes it is<br />
reasonable to include as patient-carerelated<br />
the various administrative services.<br />
However, ifthe case costs of a collection of<br />
hospitais are to be compared, then the admninistrative<br />
costs shoild not he included,<br />
since administrative costs can vary greatly<br />
across hospitais for reasons other than case<br />
mix. The remaining 3 types of accounts are<br />
all directly relatt:d t.. patient care and with<br />
the addition of the outpatient account, are<br />
referred to as the final cost centers. The<br />
-'vices associated with these accounts can<br />
he directly related to individual patients,<br />
allowing the costs to be apportioned to<br />
each patient.<br />
The direct costs of each final cost center<br />
and the portions of the cost of patientcare-related<br />
overhead accounts allocated<br />
to each final cost center (as determined by<br />
a special alg!)rithiii) represent the total cost<br />
of providing the services associated with<br />
each final cost center. An allocation statistic<br />
specific to each final cost center is used<br />
as the basis ofapportioning the costs to the<br />
MEDICAL C4#t:<br />
patienits in each ofthe l)RCs. Forexm;niple ,<br />
thile cost of nursing is allocated to patientt.<br />
based on a DRC-specific per dieni nursing<br />
weight which was derived through a study<br />
of the amount of nursing time spent witih<br />
patients in each DRG. Wl ile all of the alto.<br />
cation statistics possess some defects, they<br />
are designed to reflect more equitably the<br />
(lauiitity of aut iínstitittitoni's resources coi.<br />
sumed by the patients in each DRG. rTh,<br />
end result of the DRG cost miodel is the<br />
determination of the unit cost of treating<br />
patients in each lI)IG.<br />
5.3 Hospital Budgeting<br />
The full case mix cost accouniting approach<br />
has been applied to the budgetaryl<br />
process in 2 test hospitais. In the initial<br />
year, the unit costs (i.e., average cost per<br />
patient) in each DRCG were determined. In<br />
order to establish the following year's<br />
budget, it was only necessary to project the<br />
hospital's case mix and apply the appropriate<br />
inflation factors. Deviations from the<br />
budget due to case mix were immediately<br />
detected and the diagnostic and service<br />
areas experiencing significant deviations<br />
fromn established unit costs were isolated.<br />
The resulting unit costs in the test hospitais<br />
typically varied across DR9s by more<br />
than a hundredfold. The following DRGs<br />
illustrate this cost variation.<br />
DRG<br />
127-Ischemi c heart<br />
disease except<br />
acute myocardial<br />
intaretion with<br />
shunt or other<br />
major operation<br />
187-Gastric and peptic<br />
ulcer with<br />
gastric reseetion<br />
or other<br />
major operation<br />
with a secondary<br />
diagnosis present<br />
Tyupicl 1976i<br />
Unit Cost<br />
$9.934<br />
7,362<br />
F
Vol. XVIII, No. 2, Sn",,phl- steal<br />
112-Otitis miedia,<br />
c.lroulic .'il.sto)iditis<br />
or otosclerosis<br />
withotut any<br />
operation<br />
273-False labor<br />
.withoutt aliy op(eration<br />
- 67 -<br />
264<br />
Even within a specitic diagnostic area<br />
the DRGs provide a higlh degree of cost<br />
discrimi ination. For exampi)le, paitietits with<br />
a prinmiary diagnosis of urinary calcullus encompass<br />
4 DRGs with the tollowing typical<br />
1976 uinmit costs:<br />
Urinanj Calculus DRGs<br />
239-Without in oper-<br />
2- a0 d y i agnou sis<br />
240-IVitlhoutt an operatioin<br />
witli a<br />
s;ec( ¢{i;ir y<br />
dia;lí)nsis<br />
241-With miinor operation<br />
sIuch ;is<br />
cystoscopy or<br />
cathettcr to<br />
kiitdney<br />
242-With maijor operaition<br />
schlil as<br />
nephrotoiny,<br />
cystotoity or<br />
r'reterotoiiy<br />
Tilpical 1976<br />
L!ni .:ost<br />
$ 394<br />
774<br />
1,032<br />
2,2)93<br />
.ThL, , "en within this narrow diagnostic<br />
; artea the unit costs across DRGs varied by a<br />
factor of nearly 6.<br />
: An exaniple of a munit cost report<br />
' for DRG 121-Actute Myocardial lntiLrc-<br />
;/tion-appears in Figure 4. It compares<br />
the cost of treating AMI patients in<br />
; the same hospital across 2 differenít years.<br />
`; The box at the top of the report summainrizes<br />
-: the length of stay, charges, antd costs ex-<br />
· perienced by AMI patients in the 2-year<br />
period. The bottom portion of the report<br />
breaks down the costs experienced in<br />
! terms of the final cost centers of that hospi-<br />
. tal. For each item in the report both the<br />
absolute and per cent change across the 2<br />
CASE MIX ACCOUNTINC<br />
years a.re indicated. Such a report allows a<br />
hiospitail aininiistrator to isolate hoth the<br />
diagn(ostic and service areas wilere there<br />
are significant differences across years or<br />
relative to other hospitals if comparable<br />
data from other hospitals is available. Once<br />
the potential problem areas have been<br />
identified, the administrator can begin<br />
a more ineaningftul dialogute with the<br />
pIl)hysicians reslonsihle f)r the idenatified<br />
patients and services.<br />
5.4 Prospective Reimbursement<br />
Traditionally, most health insurers have<br />
reimbursed hospitals retrospectively on<br />
the basis of reasonable and allowable costs.<br />
While this model of reimbursement<br />
guarantees coverage for nmost hospital expenditures,<br />
it provides little economnic incentive<br />
to hospitals to control costs. Hospital<br />
prospeé.tivc-rei nlwrsement systems<br />
establish the rate of hospital reimbursemenit<br />
before the period over which the<br />
rate is to apply. The rewards and penalties<br />
inherent in a prospective systemn can<br />
potentially provide the inotivation for<br />
hospitals to become more cost effective<br />
without sacrificing the quality of medical<br />
cure. Under contract No. 600-77-022 from<br />
the lHealth Care FinancingAtAdininistration,<br />
the State of New Jersey is in the process<br />
of inmoving from a per dicm reasonable-<br />
'cost-based reimbursement system to a<br />
cost-per-case incentive-based system. 2 '<br />
The Standard Hospital Accounting and<br />
Rate Evaluation (SHARE) system is the<br />
per diemn cost-based reimburseiment systein<br />
currently in use in New Jersey. Under<br />
the SHARE system, costs are grouped into<br />
31 cost centers according to uníi form definitions<br />
of futictional centers such as laboratory,<br />
rautiology adl the like. The iinpatient<br />
costs are then regrouped within each cost<br />
center into 3 basic categories: 1) nonplhysician-controlllale<br />
costs; 2) physician<br />
costs (e.g., physician and resident salaries<br />
and ftes); ard 3) other costs which are<br />
either not controllable by the hospital, or
CA' .IX DEFINITIO)N BY DRG<br />
- 68 -<br />
DRG 121 ACUTE MYOCARDIAL INFARCTION<br />
,MEDICAL CAKE<br />
1975 1976 CHANGE % CHANGE<br />
PATIENTS 267 ' , 315 48 17.98<br />
TOTAL COST 736811.12 882896.69 146085.56 19.83<br />
UNIT COST 2759.59 2802.85 43.25 1.57<br />
DAILY COST 199.24 201.26 2.02 1.02<br />
BED-DAYS 3698 4387 689 18.62<br />
AVERAGE LOS 13.85 13.93 .08 .55<br />
TOTAL CHARGES 820269.81 1042593.69 222323.87 27.10<br />
AVERAGE CHARGE 3072.17 3309.82 237.65 7.74<br />
COST/CHARGES . .89825 .84683<br />
FINAL 1975 1976 CHANGE % CHANGE<br />
COST CENTER UNIT COST UNIT COST UNIT COST UNIT COST<br />
OIETARY 127.46 131.44 3.98 3.12<br />
ADMITTING 20.48 22.45 1.97 9.61<br />
BILLING 90.40 97.27 6.87 7.60<br />
HOTEL 159.28 180.74 21.45 13.47<br />
NURSING 702.26 681.49 -20.77. -2.96<br />
INTERNS & RESIDENTS 72.23 71.51 -.73 -1.00<br />
MEDICAL RECOROS 22.01 26.39 4.38 19.87<br />
SOCIAL SERVICE 16.36 17.50 1.14 , 6.95<br />
NEW 80RN CARE UNIT .O0 .00 .00 .00<br />
INTENSIVE CARE UNIT 60.34 69.37 9.03 14.96<br />
CORONARY CARE UNIT 636.73 509.58 -127.15. -19.97<br />
OPERATING ROOM .00 .00 .00 .00<br />
RECOVERY ROOM .00 .00 .00 .00<br />
ANESTHESIOLOGY .00 .00 .00 .00<br />
DELIVERY ROOM .00 .00 .00 .00<br />
OIAGNOSTIC RADIOLOGY 70.77 86.87 16:10 22.75<br />
RADIOISOT0?rS 3.68 4.55 .87 23.55<br />
RADIATIC:; THERAPY .00 .00 .00 .00<br />
LABORA.TORY 276.29 330.85 54.56 19.75<br />
EEG .00 .00 .00 00<br />
EKG 58.22 55.07 -3.15 -5.41<br />
MED-SURG SUPPLIES 101.24 136.18 34.94 34.51<br />
PHYSICAL MEDICINE 68.74 84.43 15.69 22.83<br />
RESPIRATORY THERAPY 77.25 82.49 5.24 6.79<br />
IV THERAPY 39.82 49.30 9.47 23.79<br />
PHARMACY 156.03 165.38 9.35 5.99<br />
OIALYSIS .00 .00 .00 .00<br />
UROLOGY .00 .00 .00 .00<br />
KIDNEY TRANSPLANT .00 .00 .00 .00<br />
Fic. 4. Sample management reprt foracute myo(ardial infartion patients treated duringa 2-year period.
VoL XVIII. No. 2, Supplemnlent<br />
- 69 -<br />
which are not to be included in the deterinaintion<br />
of the SHARE reimbursemient<br />
rate, After salary rates have l)een<br />
"equalized" in order to avoid distortions<br />
due to geographic wage differentials, controllable<br />
c,sts are grouped into 3 clusters of<br />
cost centers to allow for trade-ot'ts in treatment<br />
modes. Hlospital peer groups are<br />
foried and cost screens are set tbr each<br />
cluster of ecost celiters iu ecaih peer , mnp.<br />
When a hospital's cliuster of cost centers<br />
itils these screeuis, each cost ceniter within<br />
each cluster is screened again within peer<br />
groups. Foriiulaute then ;arc appliet to determine<br />
any uinreasonalble costs in the base<br />
period that should be disaillowed. Atter a<br />
hospital's reasonable costs have bheen determined,<br />
a preliminary per diemi reinibursement<br />
rate is cletermitned for the hospital.<br />
The proposed SHARE per diemi is<br />
re-examined in an informal review, often<br />
followed by appeals to the Departiiient,<br />
and in some cases to the coutrts. Once the<br />
SHARE per dieli is finalized, it provides<br />
the basis of reimbursement except for<br />
certain year-end adjustments made for volume<br />
variance, actual inflation, and cost increases<br />
because of legal and approved<br />
management changes, such as Certificates<br />
of Need and Blue Cross contractuial<br />
adjustments.<br />
The essential feature of the SHARE<br />
methodology is "peer groutping." This regulator,<br />
ut Ihnique was developed in the<br />
utility tield, wherein like institutions are<br />
classified according to comparable attributes<br />
in order to apply "tair" standards and<br />
develop reasonable rates. Since hospitais<br />
:display inore complexity than single-<br />
!output industries such as electric, gas or<br />
'telephone companies, the technisque has<br />
been applied not at the aggregate level but<br />
at the cost center level. It should I>e noted<br />
that the forin or unit of payment under the<br />
¿:SHARE system is the per diem and that the<br />
basis of paymient is cost.<br />
Altlhoulgh the SIlAIBE reirilursemnent<br />
i,methodology in New Jersey attained sig-<br />
CASE MIX ACCOUNTING<br />
nificant accomplishments in bringing a<br />
certain amount of order to cost reporting by<br />
hospitals in the state, there are basic elements<br />
to the structure of hospital reinimbursement<br />
which remain problems and<br />
whikh SHARE is not equipped to address.<br />
The t'uñdamental problem in cost contaíinment<br />
is defining the appropriate taols<br />
tor measuiring reasonable efficiency and eftectiveness<br />
in the hospital setting. Accurate<br />
instruiments are needed to ineasture the<br />
level of productivity and efftctiveiess iii<br />
teris of both outputs aud inputs and to<br />
respond with the applropriite t'inancial incentives<br />
or disinceintives. The attempt to<br />
measuire and compare hospital efficiency<br />
at the cost-center level fails to recognize<br />
the role of case mtix iii determining hospital<br />
costs. Ditferences or lack of differences in<br />
hospital costs at the cost-ceniter level can<br />
ihe the result of different case mix compositions<br />
anid mnay not reflect dit'le elices in<br />
hospital productivity. Further, 'te quality<br />
or etfectiveness oft' care must hb; pn)perly<br />
identified and measured in order to<br />
eval uate accurately hospital productivity.<br />
Anialyses by cost center inmay tend to<br />
obscure rather than claritfy these problenis.<br />
The second limnitation of the SHARE approach<br />
is in the existence of financial disincentives<br />
to the delivery of high-quiality,<br />
appropriate and efficient care. It is no secret<br />
that the per diem fonn of payment<br />
tends to encourage longer lengths of stay.<br />
Furthermore, the length-of-stay incentive<br />
problem is compounded by the use of cost<br />
as a basis of reinibursement. The reasonalble<br />
mieasure of a hospital financial manager's<br />
effectiveness is his success in<br />
maximizing reimbursement. The more<br />
cost is increased, the greater the revenues.<br />
Costs can be skillt'ully redistrihuted over<br />
ditferent cost centers with the el.ct of escaping<br />
peer cost screens. Another problem<br />
for the regulator, and opportunity for the<br />
amnbitious financial manager, results from a<br />
systel¡ il¡ whicli somte paticnts L)pay costs<br />
and others pay charges, compoaunded be-
CASE V' X DEFINITION BY DRG<br />
- 70 -<br />
cause the ratio of costs to charges can be<br />
manipulated. Soine opportunities t'or business<br />
gamesinauship will doubtless be<br />
found in any reimbursement inethodology.<br />
The reimbursement system must identify<br />
appropriate costs and design a financial irnf<br />
centive to monitor aud minimnize such<br />
practices.<br />
Finally, the need f'or effective communication<br />
is perhaps the most serious problem<br />
ficing regulation of the health-care inidustry.<br />
To be effective, regulators and managers<br />
must build a language to the physiciansi.<br />
It is a reflectioni of the state ofthe art<br />
that appeals in the hospital industry are<br />
managed by lawyers and accountants and<br />
therefore examine problems of allocation<br />
and tinance. If the financial and medical<br />
information were merged, it would become<br />
possible to trace the relationship betNveen<br />
the physicians' decisions and their<br />
effects on costs. From this base, the proper<br />
questions can be-franied to deal equitably<br />
with issues of effectiveness, quality and<br />
efficiency in patient care.<br />
Thus, the SHARE methodology was not<br />
equipped to address the problems of 1)<br />
defining and measuring hospital case mix,<br />
productivity and effectiveness; 2) providing<br />
incentives for better management; 3)<br />
avoiding business gamesmenship; and 4)<br />
fióstering communications between the<br />
hospital financia.l systems and physicians.<br />
In order to deal with these problenms, New<br />
Jersey is developing a prospective casecost<br />
incentive--.. in.uursement system. The<br />
DRGs will provide the basis for the definition<br />
of case types and differential reimv'nrsement<br />
rates will be established for'<br />
each DRG. In order to develop the DRG<br />
reimbursement rates, it is necessary to ob-'<br />
tain the patient abstract, billing an'd financi.al<br />
information for the case mix cost accounting<br />
model described in the previous<br />
section.<br />
Since January i976, New Jersey has<br />
been recei-',,g medical discharge abstracts<br />
from all 104 acute-care hospitals in the<br />
state. In addition, 21 self-selected hospitals<br />
MEDICAL CARr.<br />
are also submitting their billing infonna.<br />
tion. Hospital cost information is obtained¡<br />
through SHARE and is grouped inito 2<br />
categories: costs directly related to patient<br />
care, and institutional and other costs.<br />
Costs that were judged to be relatively<br />
fixed in the short run, and not directly related<br />
to patient care, were categorized as<br />
institutional costs. institutional cost centers<br />
include managerial services, facilities<br />
titainteutance, anid allied hiealth, inursing<br />
and graduate medical education costs. A<br />
separate methodology was developed to<br />
determine reasonable institutional costs<br />
comprised of a fixed sum and variable.<br />
amounts that relate to teaching comminitment<br />
and to the total amount of patientcare<br />
dollars. The patient-care costs were<br />
allocated to the patients in each DRG using<br />
the DRG-cost accounting methodology.<br />
Tie case mix cost accounting approach<br />
per-,lits the development of the institutional<br />
productivitygoals desired by thet<br />
regulators and the proper recognition of<br />
case inix complexity, differences across<br />
hospitals. Once the DRG costs have been<br />
determined, reimbursement standards !y<br />
DRG provide an appropriate set o'f goals,<br />
which are balanced to reflect the interests<br />
of both the public and the industly. The<br />
preliminary rate design has set a rate pler<br />
DRG for each hospital, composed of ¡proportions<br />
of the hospital mean case cost per<br />
DRG and the state standard (the mean caset<br />
cost per DRG across the sample of 21 hospitals>,<br />
The hospital and state proportion<br />
would always sum to unity. Thnus, for<br />
example, in the initial years of the systenm<br />
the rate per DRG might consist of 75 per<br />
cent hospital cost and 25 per cent state<br />
standard. Although the proportion of state<br />
standard would begin to approach 100 per<br />
cent over time, the early emphasis on tllhe<br />
hospital actual cost will próvide a reasoiable<br />
opportunity for institutions themiselves<br />
to make use of management information<br />
by DRC. Detailed managenment information<br />
by DRG will be provided to eaclh<br />
hospital and will be organized to help the<br />
i<br />
r5<br />
.J
'XVII. No. 2. Supplement<br />
- 71 -<br />
P)itals etfectively focus on areas of con-<br />
', in order to deal with problem areas.<br />
X:n order to realize fully the potential ofthe<br />
item, the process of implementation curt¡l>y<br />
is planned for 2 distinct stages. Stage<br />
¡l]ie initif' development, gives to each<br />
¡spital both the opportunity and responsibility<br />
for reacting to the management infrmation<br />
hy imnplementing steps Lo<br />
t:n dy inetficiency, expanding eiliciency,<br />
and opening an effective dialogue with<br />
tbeir physicianis. The motivation for dischauging<br />
thiis >butrdl is silpplied Iy prospective.<br />
incentive-based reiinbursemient.<br />
Ihus, in any given year, a hospital would<br />
retain the savings achieved by bringing in<br />
itscost per case uinder the prospective rate.<br />
.Sinm the fonn of payiment is per case rather<br />
than per diem, the unit of reimbursenent<br />
ao longer poses an incentive to increased<br />
:,<br />
:.e<br />
i<br />
CASE MIX ACCOUNTING<br />
lengths of stay. Recalculating the next year's<br />
prospective rate hased on the previous<br />
year's actual achievement serves the public<br />
interest by embedding the results in an improved-standard.<br />
The second stage in the process of implementation<br />
will involve properly crystallizing<br />
questions of inter-hospital significance.<br />
Health-care issnes will be placed in<br />
thieir DRG-specific and medical context,<br />
rather than the current collection of financially<br />
oriented appeals, thus permitting an<br />
cexamiminition of efficiency,
- 72 -<br />
MF:r :AL CAitE<br />
' .tr/ I!)N. Vol. XVIII, No. 2, Suiple>>Ieu, t<br />
6. A Case Mix Approach to Regional Planning for<br />
Acute Care Hospitals<br />
WHILE THERE ARE ONGOING USES of the<br />
DRGs in the are_;- of utilization review and<br />
hospital budgeting, cost control, and reimbursement,<br />
the application of the DRGs in<br />
the arue of hospital regional planning is only<br />
in its early stages ofdevelopmiiient. 5 Regional<br />
planning refers to the activity of organizing<br />
health-care resoutrces in a defined geograplhic<br />
regioui to aclhieve a desired state of<br />
aflairs in terms of the availability of health<br />
care of acceptable quality and cost. The<br />
primary thrust of the hospital planning activity<br />
has traditionally tocused on hospital<br />
facilities, primarily beds. Through legislation<br />
such as the Hill-Burton Act, much ofthe<br />
planning activity prior to the 1970s emphasized<br />
the adequiacy and distribuition of<br />
hospital beds to meet the needs of the population.<br />
However, the rapid increase in<br />
sophisticated'medical technology has resulted<br />
in a need to plan on a regional basis not<br />
only for hospital beds but also tor specific<br />
hospital services and equipment. Thus, the<br />
planning for the quantity and distribution of<br />
major new equipment such as computed<br />
tomography scanners or specific hospital<br />
services such as open heart surgery has become<br />
an integral part of the planning activity.<br />
Since certain types of services and<br />
equipment 4. ¡-,cessary to treat specific<br />
patient types, planning decisions will affect<br />
the case mix a hospital can treat.<br />
The modification by the planning process<br />
ofthe case mix that an individual hospital<br />
can treat will inevitably affect the case<br />
mix of the other hospitals in the region. For<br />
example, if a new service is added in one<br />
hospital, then that hospital will begin to<br />
treat additional types of patients. This will<br />
likely result in a decrease in the number of<br />
those types of patients treated at the other<br />
hospitals in the region. Further, the new<br />
service may cause the other capacities of<br />
the hospital (e.g., beds or operating rooi<br />
time) to be exceeded, requiring that the<br />
hospital cease to treat patients to whom it<br />
previously provided ¿are. The excess patients<br />
will have to be treated in tihe other<br />
hospitals in the region. Thus, the implica.<br />
tions of a planning decision can be co-n.<br />
plex and difficult to predict. A case mix<br />
approach to regional planning would have<br />
as its central focus the patients being<br />
treated and the demands they place on<br />
hospital resources. The role of each hospital<br />
in the region would be defined in terms<br />
of the case mix it treats.<br />
The basic hospital regional planníing<br />
prob)lem must consider a number of ftctors<br />
siniultanieously:<br />
1. All patients must'have access to the<br />
necessary hospital services. Access wvoull<br />
normally be defined in terms of travel time<br />
by ground transportation. An aceepltahle<br />
travel time coul(l vary by case type. depending<br />
on the prevelance of the patient<br />
type and nature of the condition (i.e.,<br />
chronic, emergency, etc.).<br />
2. The bed and other capacities of the<br />
hospitails in the region must be sufficient to<br />
ineet the demand tor care.<br />
3. Patients must only be treated in hospitals<br />
with adequate senvices, equipmnent andl<br />
specialists. The type of hospital facilities<br />
and specialists necessary for proper care<br />
will vary with patient types, For exarn ple, it<br />
might be determined that patients younger<br />
than 14 years of age should only be treated<br />
at hospitals with pediatric units.<br />
4. Minimal quality-of-care standards for<br />
each patient type must be met. The<br />
qia&lity.l:carc staihldirdls cnuld l e ais basic<br />
as a minimal mortality rate for each patient<br />
type. For example, if the mortality rate tor<br />
acute myocardial infarction patients in a<br />
hospital exceeded soine percentage, such<br />
as 20 per cent, then the planning process<br />
muist consider requiring that hospital to<br />
cease providing care to those patients. The<br />
qtiality-of-care standard could become
;.'.<br />
'Vol. XVIII. No. 2. Siupplement<br />
- 73 -<br />
¡mlore sopltisticated and include process<br />
and ontcoanit nita miires.<br />
5. The cost of providing care to the different<br />
types of patients must be reasonable.<br />
The i..formation fromi projets such as the<br />
Ntew Jersey prospective reiml)ursemnent<br />
experinment can establish the cost of providing<br />
care to eacli patient type iu eavh hospital.<br />
If a hospital proves extremely cost ineffecvtie<br />
in providing care to vertain types of<br />
patibts. llthe the pliannúing process sii.st<br />
consir er : ther a iore c(ust-efll'ctive alternative<br />
exists.<br />
TlIiIs, the basict hospital rcgional planning<br />
problem can be describedl as a system<br />
of hospitais with the capacity to treat<br />
specitied nunibers and types of patients. In<br />
addition, there aure a set of basic cquality and<br />
access constraints that must be met. However,<br />
given that the capacity boiunds and<br />
access and quality constraints can be met<br />
by a number of alternative cotigurattiotns<br />
of case mix, the alternative requiring the<br />
least cx)st is likely to be the preferred alternative.<br />
Such a probleni can be analyzed<br />
nsing linear programming techniques. The<br />
DRC can provide the basis for establishing<br />
hospital case mix. A case mix-based linear<br />
progranming model of the regional plan-<br />
.ning probleim should prove to have many<br />
CASE MIX APPROACH TO PLANNING<br />
iminmediate practical applications. For<br />
example, suptpose a proposal to close a particular<br />
hospital had been made. The regional<br />
planning model could be used to<br />
suygest the most cost-effective means of<br />
¡tistributing the closed hospital's case mix<br />
to the other hospitais in the region while<br />
still maintaining adequate access and quality<br />
andl not exceeding the capacities of any<br />
hlospital. Alternatively, if there were an<br />
existing recommendation for the distribution<br />
of the closed hospital's case mix, then<br />
the model could he used simply to siminlate<br />
the impact oft'the case mix changes un<br />
the other hospitals and describe that impact<br />
in terms of various hospital parameters,<br />
such as occiupancy rates and reinmbursement<br />
levels. There are many other<br />
examples of the use of such a m¡odel. If<br />
there were significant changes in the composition<br />
of case types projected becvaise of<br />
a new cure or an outbreak of an inflctious<br />
disease, then the modeliould be usedl to<br />
evaluate the impact on the hospitais in the<br />
region. Thus, while a case mix regional<br />
planning model is only in it's early stagesxf<br />
development, it does hold the potential to<br />
be a powerful tool for the hospital planning<br />
process.
- 74 -<br />
M i.]DICAL C(ARIF:<br />
Fe,-n#arl lv0. VSm. VIIll No. 2, Supplement<br />
PATIENTS treated in an acute-care facility<br />
can Yvary considerably in both the duration<br />
and intensity of services required to provicie<br />
appr(>priate patient care. The relative<br />
amounts and types of hospital outputs<br />
utilized >y individttal patients are<br />
depelident on both the condition oí the<br />
patient and the treatnment process<br />
employed. By relating the demographic,<br />
diagilostic. aud therapeitic clharaiteristics<br />
of patients to the hospital outputs they<br />
utilize, a patient classification scheme can<br />
be developed wvhich provides the<br />
tramework for hoth the specification of<br />
hospital case mix and the measurement of<br />
the impact of case mix on hospital utilization<br />
and performance. The Diagnosis-<br />
Related Groups represent an attempt to<br />
provide such a patient classification<br />
scheme. As currently defined, the DRGs<br />
provide a manageable number of patient<br />
c;asses (383) that are exhaustive and minutually<br />
exclusive with respect to the types of<br />
patients seen in an acute-care setting.<br />
Further, the DRGs provide patient classes<br />
that are clinicially consistent and that have<br />
similar patterns of output utilization as<br />
measured by length of stay.<br />
The comparison of patient data across<br />
institutions or Droyviders will invariably reveal<br />
the exi-t nC:e of differential levels of<br />
utilizatior and performance. A comparative<br />
analysis by average length of stay, cost,<br />
or any other aggregate measure is not<br />
meaningful unless the impact of different<br />
case mix compositions can be determined.<br />
The DRGs can provide a framework for<br />
establishing the effects of case mix tas well<br />
as for identifying diagnostic areas with potential<br />
problems. The goal of most comparative<br />
analyses is to isolate problem<br />
areas s(; 4h.t corrective measure, ann be<br />
initiated. If prograims aimed ait itiaproviuig<br />
the performance ofthe hospital health-care<br />
system are to be successful, managers and<br />
7. Summary and Conclusions<br />
regulators must establish an effective<br />
dialogue with those responsible for the delivery<br />
of services, the physician comimunity.<br />
The DRGs provide the first step in suclh<br />
a dialogue since problems defined in the<br />
contextof DRGs are understandable fronm a<br />
clinical perspective.<br />
The various actual and potential applications<br />
ofthe DRGs in the areas of utilization<br />
review, hospital bucdgeting and cost coatrol,<br />
prospective reimbursement and regional<br />
planning emphasize the central role<br />
of the patient. By focusing on the types of<br />
patients being treated, programs responsihle<br />
for these activities will share a common<br />
conceptual basis even though they are<br />
concerned with different aspects of the<br />
health care system. While the applications<br />
to date llave been implemented to meet the<br />
immediate needs of the individual programs,<br />
future work will be directed toward<br />
exploring the potential of the DRGs in<br />
achieving better integration and.coordination<br />
of the different program goals and.<br />
activities.<br />
The current set of 383 DRGs were developed<br />
in light ofthe available data and its<br />
limitations at the time of their construction.<br />
As such, they representjust one imple mentation<br />
of an evolving series of patient<br />
classification schemes. As more comprehensive<br />
and reliable patient data become<br />
available and the practice of medicine<br />
changes, the DRGs must adapt to reflect<br />
these changes. To this end, it is felt that the<br />
technology and strategy used in forming<br />
the DRGs can be applied in the developnment<br />
of future generations of classification<br />
systems. Indeed, a major revision and<br />
evaluation ofthe DRGs will be undertaken<br />
as soon as ICD-9-CM data are available in<br />
sníflicient quantities. Further, work has<br />
begun in extending the approach into otlier<br />
areas of health-care delivery, in particular,<br />
ambulatory care.2'<br />
.1 1
:`". XVIII, No. 2. Stupplenent<br />
- 75 -<br />
1. Departsment of Heilth, Education, anid Welfire.<br />
A.UfOGRP patient classification .scheme and diagssois<br />
related groups (DRGs). Health care financing<br />
lntsn a;'nd contracts report series. Washington, D. C.:<br />
Departnhilc' nr I healthi Edueationt. uani Welfre. 1978.<br />
tDHEWV publication no. (HCFA)03011 979.)<br />
2. Avenil RF. Atpplication of case lnix cost acecountiLg<br />
to hospital heulgeting and prospective reimbursement<br />
pre*sented at tlhie 38t1h mneeting of the<br />
Acadenmy oF .\laiilgeii, eit. San Franicisco, August<br />
3. Bays CVy. Casc-miix tlilli.retnces l)thvween ¡ionpmiit<br />
and fibr protit hospitais. Inquinr 1977; 14:17.<br />
4. Ceite-r Gibr Ileahlthl Stildies. D)i:gnosis relited<br />
group relorts fir l>SHO diatil)iasts. New lILven: Yale<br />
University Center Hlealth Studies. 1978.<br />
5. Chemow R. A casemix approach to regional<br />
planning: an alpplication ol linear programniing.<br />
Ph.D. dissertatioín. New vlfave'n: Yale Unitersity. i¡<br />
progress.<br />
·6. Coniínission oit Pnrf issional; a;d H lIosptital Ac'tivities.<br />
IEospitail adaptation ot> ICDA. 2ncd ed. Aun<br />
Arbor: Conuiuission tn Prolssisumal anel Hospital Activities.<br />
I968.<br />
7. Commiission onl Prt)fssional and Hospital Activities.<br />
Liengthl of stay inl PAS hospitalis. hy diagnosis.<br />
Ann Arbor: Cnmtiiissioín on Professional a;ud Hospital<br />
Activities. l976.<br />
8. Fetter RB. Mills R. Riedel DC. Thoinpsoi JD.<br />
IThe application of diagnostic spevcific cost ipnuiles to<br />
,.tost and reimhnursement control in hospitals. J S :d<br />
; Systems 1977;1:137.<br />
.; 9. Fetter RB. Thomipilson JDI, Milis RE. A system fir<br />
,'ost arid reinmblursement conitrl iiin hioslitais. Yale Biol<br />
;J 1976;49:123.<br />
10. Freenman JL. Applications of the AUTOGRP<br />
eomanputer system as a patient care monitoring mechanism<br />
fbr PSRO's. Presented at the 38th meeting of the<br />
i:Acaden» oi' Management, San Francisco, August<br />
¡1978.<br />
? 11. Hill BA. Principles of medical statistics. New<br />
&Yorlk: Oxford University Press. 1971.<br />
e'i:<br />
References<br />
REFERENCES<br />
12. Health Care Financing Administration. Implementation.<br />
evaluation and extension of a patient<br />
iJme mnitoring nechanisnim. Final report Conbtact<br />
240-75.0051. Baltimore: Health Care Financing Administration.<br />
October 1977.<br />
13. Public Health Service. International classification<br />
of diseases. eighth revision. Washinglon D. C.:<br />
U.S. Covernnient Printing Olfice. 1968. (Publication<br />
no. 1693.)<br />
14. Ktitagit.va EIM. Comipotlests o(f dlillrfenrte Ihetween<br />
two rates. J Am Stabsticd Assoc 13955;50:296.<br />
15. Lave IR. Lave LB. The extent oirole diltbrentiation<br />
among hospitals. lealth Serv Res 1971;6:15.<br />
16. l ave JR. Leinlnuarlt S. The.- ost and lngth of£a<br />
hospital stay. Ihi(litiry 1976;13:327.<br />
17. Lee ML. Wallace RL. Classilication ofdiseu-ies<br />
lor hospital cost analysis. Inquiry 1972;9:69.<br />
18. Lee ML. Wallace RL. Problems in estinmating<br />
llaltil)rKlit cost hietiions: ai llplicLatioii to hos¡itals.<br />
West Ecrm J 1973;11:350.<br />
19. Luke RD. Dimnensions in hospital ea;se mix<br />
meitsurement. Ilquiry 1979;16:38.<br />
20. Mills RE. Fetter RB. Riedel DC. Averill RF.<br />
AUTOCGHP: an interactie corlotitetr, ystain fior the<br />
analysis of health care data. Mled Care 1976;14:603.<br />
21. New Jersey State Department ofl tealth. A pnríspective<br />
reimbursenment system hase4 oln patiernt<br />
case-mix for New Jersey hospitals. 1976-1978. Annual<br />
Report. November 20, 1977.<br />
22. Ratlirty J. Pattms ofhospital use: an iatlysis of<br />
short-nin variations. J PolitiCal Econ 1971;79: 154.<br />
23. Ranoftky. AL. Utilizatiotn ofshort stay hIospitais:<br />
annual sumniary firrthe United Staltes, 1976. Rc'cksille.<br />
MD: National Center ftr Health Statistics. 1978. (Vital<br />
and heitlth statistics. Series 13. tno. 26) (DHE\W publieation<br />
no. (PtlS)78-1788.)<br />
24. Social Sevurity Administration. Progress report:<br />
developinent. testing aind evaluation ofa proslpective<br />
c¿tse-paymetnt reimhurseinent system. WVashington.<br />
D. C., SLocial Security Administration, 1978.<br />
25. Sonquist JA, Morgan JN. The detection of interaction<br />
effeets. Ann Arbor: Institute for Social Research.<br />
University of Michigan, 1964.
- 76 -<br />
> .CAL CARE<br />
t brNOar 1980, Vol. XVIII, No. 2. Supplement<br />
Appendix<br />
Diagnosis-Related Group Descríptions<br />
Major Diagnosis Category Diagnosis-Related Croups<br />
01: Infectious Diseases<br />
02: Malignant Neop4!isnm<br />
lf the Digestive<br />
Systemn<br />
03: Maliignant Neoplasm<br />
of the Respiratory<br />
System<br />
04: Magnlignat Neoplasm<br />
of the Skin<br />
05: MaUiignant Neoplasm<br />
of the Breast<br />
06: Malignant Neoplasm<br />
of the Female<br />
Reproductive System<br />
001<br />
002<br />
003<br />
004<br />
005<br />
006<br />
007<br />
00i<br />
009<br />
010<br />
011<br />
Infectious Disease (Enteritis, Diarrhea) with Age less than )16<br />
lnfectious Diseiase (Enteritis. Diarrhea) with Age greater than IS<br />
Infectious Disease (Viral Disease, VD, Meningitis) withoiut Sec<br />
ondary Diagnosis<br />
Infectious Disease (Viral Disease, VD. Meningitis) with Sec.<br />
Ondary Diagnosis<br />
Infectiutis Discase (Blood Infectioi,. TB, Salmonenllu) w.ithouit<br />
Surgery<br />
Infectiois Disease (Blood Infection. TB. Salmonell;a) wrth<br />
Surgery<br />
Cancer of tik? Mouth, Totigue. Large Intestinc. Liver. C.allIl.~I.<br />
der without Siurgery<br />
Cancer of the G1 System (Esophagus. Stomach, Pancreas, Sm.ll<br />
Intestine, Recétum) without Surgery<br />
Cancerofthe CI System with Surgical Procedure (Biopsy, Endnscopy,<br />
Local Excision, Centesis) without Secondary Diagnosis<br />
Cancerofthe Cl System with Surgical Procedure (Biopsy. Endous<br />
copy, Local Excision, Draining) with Secondary Diagnosis<br />
Cancer of the Cl System with Surgery (Gastric Resection. Colon<br />
Resection, Esophagus Resection)<br />
012 Cancer of the Rlespiratory System (Trachea. Lung, Larynx, Thorax.<br />
Mediastinum) without Surgery without Secondary Iiagnosis<br />
013 Cancer of the Respiratory System (Trachea, Lung, Larynx.<br />
Thorax, Mediastinum) without Surgery with Secondary Diagnosis<br />
014 Cancer of the Respiratory System with Surgical Procedure (Biopsy,<br />
Endoscopy, Excision of Lesion) without Secondary<br />
Diagnosis<br />
015 Cancer of the Respiratory System with Surgical Procedure (Biopsy.<br />
Endoscopy, Excision of Lesion) with Secondary Diagnosis<br />
016 Cancer of Respiratory System with Surgery (Lobectomy, Laryngectomy,<br />
Radical Resection)<br />
017<br />
018<br />
019<br />
020<br />
Cancer of the Skin except Malignant Melanoma without Seeondary<br />
Diagnosis<br />
Cancer of the Skin except Malignant Melanoma with Secondary<br />
Diagnosis<br />
Cancer of the Skin-Malignant Melanoma with Surgical Proce-<br />
'dure without Secondary Diagnosis<br />
Cancer of the Skin-Malignant Melanoma with Surgical Procedure<br />
with Secondary Diagnosis<br />
021 Cancer of the Breast without Surgery with Age less than 63<br />
022 Cancer of the Breast without Surgery with Age greater than 62<br />
023 Cancer of the Breast with Surgery without Secondary Diagnosis<br />
024 Cancer of the Breast with Surgery with Secondary Diagnosis<br />
025 Cancer of the Female Reproductive System (Uterus, Cervix, Vagina,<br />
Ovary, Fallopian Tuahe) without Surgery without Secondary<br />
Diagnosis<br />
026 Cancer of the Female Reproductive system (Uterus, Cervix, Vagina,<br />
Ovary, Fallopian 'rube) without Surgery with Secondar)<br />
Diagnosis<br />
027 Cancer of the Female Reproductive System with Surgical Procedure<br />
(D&C, Biopsy, Excision of Lesion) withomit Secondary<br />
Diagnosis
,VoL XVIII, No. 2, Supplement<br />
Major Diaglosis Categtory<br />
07: Mlalignant Neoplasm<br />
;il the Male<br />
Rcrodhaehctive Systemi<br />
08: Malignant Neoplalissl<br />
o. tthe Urinary System<br />
"09: Malignant Neoplasm<br />
of O
- 78 -<br />
CASE b'IX DF.INITION BY DiRG MEDICAL. CAR.:<br />
Mliajor L)iaglno>sis Category<br />
1I: -BiUnig Neiol)hilson or<br />
the Feinale Repro.<br />
ductive System<br />
12: Benign Neoplains of<br />
O)ther Sites<br />
13: Diseases of Thyroid<br />
and Other Endocrine<br />
Clands<br />
14: Diabetes"<br />
15: Nutritional and Other<br />
Metabolic Diseases<br />
16: Diseases of the Blo>d<br />
and Blhod Forming<br />
¢ )rgai.,<br />
(153<br />
054<br />
055<br />
056<br />
057<br />
058<br />
í)59<br />
Blen¿iKg, 'Frnur (P:pqilhluna. Polyp) of tihe Uteruns. Vagina;, Vu'lva<br />
x\ hlmut St%;vindary Diagnosis<br />
Benign Tumor (Pípilloma. Polyp) of the Uterus. Vagina. Vulva<br />
with Secondary Diagnosis<br />
Benign Tumor (Fibroma) of the Uterus. Ovary without Surgery<br />
Benign Tunmor
..<br />
Vol. XVIII, No. 2. Supl|lemcent<br />
.Major Dinagnasis Category )Diignosis-Beláted Groups<br />
17: Psychoses Not<br />
Attributed to Physical<br />
Conditions<br />
18: Neuroses<br />
19: Alcoholic Mental<br />
Disorder and Addiction<br />
20: Other MentaiiJ Disorders<br />
21: Diseases of the<br />
Central Nervous<br />
System<br />
Diseases of the<br />
Pe-'rh-ral Nervous<br />
S?-:em<br />
Discases of the<br />
Eye<br />
083 &lediterancan Anemia, ilcanpholilia witliout Stargery withlout<br />
Secondary Diagnosis or with Mlinor Secondary Diagnosis with<br />
Age greater th;rn 10 _<br />
084 Disease of Blood Hemoglobin without Surgery without Secondary<br />
Diagnosis or with Minor Secondary Diagnosis<br />
085 Disease of the Blood (Anemias). Blood Forming Organs (Spleen)<br />
without Surgery with Major Secondary Diagnosis<br />
086<br />
087<br />
Disease of the Blood (Anemias). Blood Forming Organs with Surgery<br />
with Age 2-52<br />
Disease of the Blond (Anemias). Blood Forming Organs with Surgery<br />
with A&ge less tiian 1 or greater thli. .53<br />
I88 Schizophirenia (Pamnoid, Catatonic, Unspecified) Invohltional<br />
Meldancholia with Psychiatric Sertice<br />
089 Schizophrenia (Parainoid, Catatonie. Unspecified) Involutional<br />
SI.ialacrholiil without Psychiatric Servive<br />
090 SSchizophrenia (Alfi.ective, Acute Episotde), Mlaitic-Depressive<br />
Psychosis<br />
091 Neurosis (Anxiety, Hysterical, Phobic, Hypochandriacal UnslXcified)<br />
092 Neurosis (()Ohsessiv-Conlpulsive. Depressive), Persoiality-<br />
Disorders<br />
093 Alcoholisnm without Secondary Diagnosis or with Minor Secondauy<br />
Diagnosis<br />
094 .Alcoholismn with Major Secondary Diagnosis (Liver Cirrhosis.<br />
I)elirium Tremens, Other)<br />
095 Drug Dependence. Physical Disorder (Probably Psychiatric<br />
Origin), Cephalgia<br />
096 Psychosis, Non-Psychosis Related Brain Condition<br />
097<br />
098<br />
099<br />
100<br />
101<br />
102<br />
103<br />
104<br />
105<br />
106<br />
107<br />
108<br />
109<br />
110<br />
111<br />
- 79 -<br />
APPENDIX<br />
Epilepsy, Migraine. Brain Disurder (Unspecified) withoit Surgery<br />
without Second:ary Diagnosis<br />
Epilepsy, Migraine, Brain Disorder (Unspecified) without Surgery<br />
with Secondary Diagnosis<br />
Multiple Sclerosis, Paralysis Agitaas, .leningitis, Hemiplegia<br />
withont Surgery<br />
Disease of the Central Nervous Sysfeln with Surgical Procedure<br />
(Nerve Block, Other)<br />
Disease of the Central Nervous System with Surgery (Laminectony.<br />
Spinal Fusion Ventricular Shunt)<br />
Facial Paralysis, Neuralgia (Trigeminal, Other Unspecified) withotit<br />
Surgery<br />
Sciatica, Polyneuritis without Surgery<br />
Disease of the Median Nerve with Surgery<br />
Disease of dithe Peripheral Nerves except Sedian with Surgical<br />
Procedure (Nerve BIlck, Other Unspecified)<br />
Disease of the Peripheral Nerves except Median with Surgery<br />
(Spinal Cord, Nerve Roots)<br />
Cross Eyedness, Cataract, Cyst of the Eyelid withoit Surgery<br />
Glaucima, Corneal [imtlanimation/Ulveration, Disease of the Iris,<br />
Retina witliout Smtrgery<br />
Disease of the Eye with Surgical Procedure (Muscle Repair of<br />
Eyelid, Other)<br />
Disease of the Eye with Surgical Procedure (Removal of Lens,<br />
IIL! .on into Sclera<br />
Dinsi.eS of the Eye witIh Surgicail Procetdurte (Reattaehment of<br />
Hetina. ielpair of Cornea)
CAbS . MIX DEFINITION BY DRG<br />
Major Diagnosis Category<br />
24: Disease of the<br />
Ear and Mastoid<br />
Process<br />
f25: Hypertensive Heart<br />
Diseases<br />
26: Acute Myocardial<br />
I nfrction<br />
27: Ischemie He.art Diseaises<br />
Except A1MI<br />
28: Arrhvthnmia and Slowed<br />
Conduction<br />
29: Heart i adlure<br />
30: Carditis, Valvular<br />
and Other Diseases<br />
112<br />
113<br />
114<br />
115<br />
116<br />
117<br />
118<br />
119<br />
120<br />
121<br />
- 80 -<br />
Diagnosis-Related Groups<br />
MEDICAL CARE<br />
Disease of the Middic Ear (Iiulanimation, Chronic Mastoid Bone<br />
Inflammation) without Surgery<br />
Disease of the Inner Ear (Infiammation, Menieres Disease) without<br />
Surgery. _.<br />
Disease of the Ear with Surgical Procedure (Incision of Membrane,<br />
Removal of Adenoids, Other)<br />
Disease ofthe Middle Earwith Surgery (Removal of Bone, Repair<br />
of Membrane)<br />
Disease of the Ear with Surgery (Removal of Mastoid Bone, Excision<br />
of Middle Ear, Other)<br />
Hypertensive HeartiDisease without Surgery without Secondary<br />
Diagnosis or with Minor Secondary Diagnosis<br />
Hypertensive Heart Disease without Surgery with Major Secondary<br />
Diagnosis<br />
llypertensive Heart Disease (Fatal) with Kidlney Involvemient<br />
without Surgery with Major Secondary Diagnosis<br />
Hypertensive Heart Disease with Surgery<br />
Disease of the Heart-Acute Myocardial Infaretion<br />
122 Disease of the Hieart, Ischemia (Blood Deficiency) except AMI<br />
witlhout Surgery withouit Secondary Diagnosis<br />
123 Discase of the Heart, Ischeinia (Blood Deficiency) except AMI<br />
without Surgery with Minor Secondary :)iagnosis<br />
124 .sease of the Heart, Ischemia (Blood 'eficiency) except AMI<br />
witlmit Surgery with Major Secondar Diagnosis<br />
125 Disease of'tlie Heart, Ischemia (Blood Dei.ciewcy) except AMI<br />
with Cardiae Catheterization<br />
126 Disease of the Heart, Ischemia (Blood Deficiency) except AMI<br />
with Surgical Procedure (Endoscopy, Insertion of Electronic<br />
Devíice)<br />
127 Disease of the lieart, Ischemia (Blood Deficiency) except AMI<br />
with Surgery (Shunt, Otlier Major)<br />
128 Disease of the Heart, Irregular Heart Rhythm, Slowed Conduction<br />
without Surgery without Secondary Diagnosis or with N inor<br />
Secondary Diagnosis<br />
129 Disease of the Heart, Irregular Heart Rhythm, Slowed Conductio.n<br />
without Surgery with Major Secoandary Diagnosis<br />
130 Disease of the Heart, Irregular Heart Rhythm, Slowed Conduction<br />
with Replacement of. Heart Device or Cardiac Catheterizatiun<br />
131 Disease of the Heart, Irregular Heart RhytIm, Slowed Conductión<br />
with Insertion of Electronic Heart Device<br />
132 Disease of the Heart, Failure (Poor Function) without Surgery<br />
133. Disease of the Heurt, Failure (Poor Function) with Surgery<br />
134 Disease of the Heart, Inflammation, Valve Problem without Surgery<br />
without Secondary Diagnosis or with Minor Secondary<br />
Diagnosis<br />
135 Disease of the Heart, Inflammation, Valve Problem without Surgery<br />
with Major Secondary Diagnosis<br />
136 Disease of the Heart, Inflammation, Valve Problem with Cardiac<br />
Catheterization without Secondary Diagnosis or with Minor Secondary<br />
Diagnosis<br />
137 Disease of the Heart, Inflammation, Valve Problem with Cardiac<br />
Catheterization with Major Secondary Diagnosis<br />
t
i,..X VIII. No. 2. Supplemeiint<br />
- 81 -<br />
Major Diagrioosis Category Diagnosis-Ielated Grotups<br />
:31:- Cerebrovascular<br />
:: Diseases<br />
32: Diseases of the<br />
Vascular System<br />
33: Pulmonaary Emobolismn<br />
34: Phlebitis aud<br />
'1 tlro.ial>phlebitis<br />
35:<br />
Hemorrhoids<br />
l{ypertruphy uf Tonsil<br />
and Adenoid<br />
*37: Acute Ulpex'r Respiratory<br />
T'ract Infection and<br />
* Influenza<br />
.38. Other Discas-tir of the<br />
Uppe~r Respitatory Tract<br />
APPENDIX<br />
138l Disease of the Heart, Inilamniation. Valve Probleni with Surgery<br />
(Valve Replacement. Other Major)<br />
139 Circulatory Disorder bi the gíin. Occasional Blood Deficiency<br />
without Surgery without Secondary Diagnosis or with Minor Seondary<br />
Diagnosis<br />
140 Circulatory Disorder of the Brain. Occasional Blood Deficiency<br />
without Surgery with Major Secondary Diagnosis<br />
141 Blood Clot in Brain Obstructing Circulation without Surgery<br />
withiint Secondary Diagnosis or with Miinor Secondary Diagnosis<br />
142 Blotd Clot iio Brain Ol>structing Circulation witfhout Surgery<br />
with Major Secondary Diagnosis<br />
143 Brain Hemnorrhage (Stroke) without Surgery without Secondary<br />
Diagnosis or with Minor Secondary Diagnosis<br />
144 Brlin llenmorrhage (Stroke) without Sorgery with Mijor Secundary<br />
Diagnosis<br />
145 Circulatory Dysfunction in Brain with Surgery<br />
146<br />
147<br />
148<br />
149<br />
150<br />
151<br />
Disease of the Circulatory System. Inflamnimation of the Lymph<br />
Glands. Varicose Veins (Legs). Raynauds Disease without-<br />
Surgery<br />
Discase ,of the Circuilatory Systeni (Hardening of Arterial WValls.<br />
Arterial Blood Clot) withont Surgery without Secondary Diagnosis<br />
.or with Minor Eecondary Diagnosis<br />
Disease otf the Cirt -datory System (Hardening of Arterial Wialis,.<br />
Arteri¿al Bi>oul C: t) witho(it Surgery with Muajor Se'ondary-<br />
Diagnosis<br />
Diseiase of the Circulatory System with Surgical Proced*re (Excision<br />
of Varicose Veins, Other) with Age less than 51<br />
Disease of Vascular System with Surgery (Excision of Varicose<br />
Veins, Other) with Age greater than .50<br />
Disease of Vascular Sytem with Surgery (Excision of Nterve,<br />
Vessel) without Secondary Diagnosis<br />
152<br />
153<br />
Disease of Vascular System with Surgery (Excision of Ni-&ve.<br />
Vessel) with Secondary Diagniosis<br />
Disease of`Vascular System with Surgery (Arterial Recunstruction,<br />
Ampitation of Extremity)<br />
154<br />
155<br />
156<br />
157<br />
158<br />
159<br />
160<br />
161<br />
Blood Clot ., tlhe Lung without Secondary liagnosis or with<br />
Minor Secondary Diagnosis<br />
D. .ad Clot of the Lung with Major Seconrdary Diagnosis<br />
IBl"uinimation of the Veins, Blood Clot without Secondary Diagnosis<br />
or with Minor Secondary Diagnosis<br />
Inflammation of the Veins. Blood Clot with Major Secondary<br />
Diagnosis<br />
Hemorrhoids<br />
Enlargement of the Tolnsils/Adenoids<br />
Acute Uppl)r Blespiratory Tract Inletio. m Ilnfluenza with Age less<br />
thano 45<br />
Acute Upper Respiratory Tract Infection Ilnfluenza with Age<br />
greater than 44<br />
162 Disease of the Upper Respiratory Tract except Acute Upper<br />
Respiratory lnfection and Influenza without Surgery
CAS E MIX DEFINITION BY DRG<br />
.Major Dininosis Category<br />
39: Piineinofnia<br />
40: Bronchitis<br />
41: .Asthma<br />
42: ()tlher Luing and<br />
Plecirl I)isea.es<br />
43: Diseases of the Oral<br />
,:ait'. Salivary Glandtis<br />
a,.1tl Jaiw<br />
44;: ;astrie aud Peptie<br />
U leer<br />
45: Upper Castn- Intestinal<br />
Diseases except<br />
Gasutrie and Peptie<br />
Ulcer<br />
46: AI)Ilpxtlivitis<br />
- 82 -<br />
Diagniosis-Related Cronips<br />
SIEDICAL CARE<br />
163 Disease of the Upper Respiratory Tract with Surgical Procedure<br />
(Biopsy, Visualizations of the Nasal Septuni)<br />
164 Disease of thc Upper Respiratory Tract with Surgery (Nose Re.<br />
construction, Inciniun andPraiinaige of Sinuis)<br />
165 PPneunionia with Age less than 31<br />
166 Pneiuanoniia without Surgery without Secondary Diagnosis wvith<br />
Age greater than 30<br />
167 Pneumnonia witlihout Surgery with Secondary Diagnosis with Age<br />
greater th el¡i 30<br />
168 Pineunionia with Surgery<br />
169 Bronchitis with Age less than 46<br />
170 Bronchitis without Seclidary Diagnosis or with Minor Second.<br />
alry i)iaglosi.s with Age gr.-ater thai .i5<br />
171 o"nchitis with Major Secondary Disgnosis withl Agt greater<br />
thall 45<br />
172<br />
173<br />
174<br />
175<br />
176<br />
177<br />
L78<br />
179<br />
180<br />
Asthiia with Age less tlhan 31<br />
Asthina without Seconildary Diagiíosis with Age greater thal :(1<br />
.Astlthma wxith Sevouidary liaginosis with Age greater thlia, 30<br />
Lung Collapse. Pleurisyg, Punlioniary congestion withsoit Surgoery<br />
Emtphysema, Eímpyema, Abscess. Acute Swelling without Stirgery<br />
witholit Secondary Diagnosis or with Minor Secondar-<br />
C .lgsosiss<br />
.kll>Wsciii. ELi)l>yetni;, Al>bsess, Acute Swevlli g witout Sil-<br />
^,ery with NlaUjr Secondary Viagnosis<br />
Dlisease of the Lutng and Pleaura with Surgical Proced¢iu (Bronchoscopy,<br />
Cliest acisio, Other) withiout Secoindary Diagnosis<br />
D)isea s the e Lung and Pletura with Surgical Procedure (Bronchooscopy,<br />
Chest litcision, Other) with Secondalry Di)i;uosis<br />
Disease orf the Lunlg adil Pleuira with Surgery (Removial of Lole:<br />
Other Major)<br />
181 .liinor Protileis of thle Teeth<br />
182 Mliaor Prolalemiís of the Teeth (Jaw, Salivary Clanis, Other Oral<br />
Solt 'risstue)<br />
183<br />
184<br />
"45<br />
186<br />
187<br />
188<br />
189<br />
190<br />
191<br />
192<br />
Stomach Ulcer without Surgery without Seconlary DiagnPosis<br />
Stomach Ulcer without Surgery with Secondary Diagnosis<br />
Stom;ich Ulcer with Surgical Proceduire (iop>sy, Visutlizatiou.<br />
Other)<br />
Stomltach Ulcer with Surgery (Remnoval of Portion of Stomach.,<br />
Other tMajor) without Secondary Diagnosis<br />
Stomach Ulcer with Surgery (Remnoval of Portion of Stoinmach,<br />
OCther Slajor) with Secumnlary Diaguosis<br />
Upper Gl Disease Except Stomach Ulcer without Surgery without<br />
Seco)ndary Diagnosis<br />
Upper Cl Disease Except Stomach Ulcer without surgery with<br />
Secondary' Diagnosis<br />
Upper CI Disease Except Stuiomch Ulver with Surgical Procedure<br />
(Visualization, Other Minor) without Secondary Diagnosis<br />
Upper GI Disease Except Stomnach Ulcer with Surgical Procedure<br />
(Visualization, Other Minor) with Secondary Diagnosis<br />
Upper GI Disease Except Stomach Ulcer with Surgery<br />
¡1$1<br />
f Appendicitis (without Peritonitis) without Secondary Diagnosis<br />
1IJ4 A¡ppldivitis (witlh>iSt l'erito>itnil) withi Sccumsiary Diagnuosis<br />
195 Appendicitis (with Peritonitis, Other) without Secondary<br />
Diagnosis s
T<br />
XVIII. No. 2. S.pphlts"t<br />
.i¿jor Diagnosis Citegory<br />
Hernia of tlhe<br />
-Axidouiínal Cavity<br />
48: Esteritis. Divertievula,<br />
a¿iad Faniction[al Disorlers<br />
olfthe Intestineic<br />
*.49: D iseaises of thie Antis<br />
50: SlisteeIlah.ols Disea.ses<br />
ot' the litestine auli<br />
I>eritona.llie<br />
51: Disea.ses ol' the<br />
Liver<br />
52: Diseases of the<br />
't.all¿«hlhhr austl Bilh,<br />
Dlat't<br />
1t> A>pil)edicitis (witla Peritonitis. Otiher) with Secundary<br />
Diiagnusw.<br />
197<br />
198<br />
199<br />
200<br />
201<br />
203<br />
204<br />
205<br />
206<br />
207<br />
208<br />
2(09<br />
210<br />
- 83 -<br />
Grutips<br />
AbIdomainsal Hernia with Age less than 15<br />
lnginua!ul fHieriia (without Obstruiction) with Age greater than 14<br />
a.ld less thalan 65 withoiut Secondiry. Diaginosis<br />
liguina;l Hernia (withoiat Oblstrtuction) with Age greater than 14<br />
antd less tihan 65 with Secondary Diagnosis<br />
Alblonminal Hernia Except Simple Inguinal with Age greater than<br />
14 atud less thin 6.5 withosit Snrgery<br />
AlIlaminal lernia Except Simuple Iagaiuaal witlh Age greater than<br />
14 aud less tlansal 65 with Minor Surgen.<br />
Aldlomiituial I lernia Excel)t Sinple Inguinal with Age ireater thtan<br />
14 asad less than 65 with Mlajor Surgery<br />
Ahdsomi.al llernia with Age grecater thlan 64 wvithoitat Sargery<br />
AldlomialI llernia witih Age greater thllan 64 witil Ninor SuIrgery<br />
Ahblomiial liernia wviti Age greater than 64 with Mlajor Surgery<br />
Faiunctional Disorder of the Intestine without Surgery<br />
Intestiiial Ponuching, Regioial Enteritis. Ulcerative Colitis withiait<br />
Saurgery<br />
lntestinaJl PocilnvIiag (Functionlal Disorier) wvith Minor Surgery<br />
witliolnt Sevoiuldarv D)iagnosis<br />
lntestisial Pouching (Functional Disorder) with Mlinor Surgery<br />
with Secolidary Diiagiosis<br />
Iiltestieail P¡ witi Mlajor Surgery<br />
(lie^e lichi, )thleOr)<br />
211 Disease ol'the Anos without Secondary Diagnosis<br />
212 Disease ofl'the Aruis with Secondairy Diagh)osi6<br />
A.PP.EN DIX<br />
213<br />
214<br />
Misceellaneo.us Disease of the Intestine and Abdominal Lining<br />
withl Age less th.ali 56 withotut Snrgery<br />
Dliscell.eons<br />
Disease fIt' thc lntestiLne and Abdominal Living<br />
with Age greater tiian 55 withont Surgery without Secondary<br />
Diagnosis<br />
215<br />
216<br />
Mliseelliaeoa.~ Disease of tile Intestine aud Abdominal Lining<br />
withl Age greater than 55 withouit Snrgery with Secondary<br />
Di¿agnlosis<br />
Ilisell&iai.e'ois i)isea.se *. thei Intestiice iantd Allndominlal Lining<br />
witl Snargical Procedure (Local Incision, Excision)<br />
217<br />
218<br />
.liscellaneous Disease of the Intestine and Abdominal Lining<br />
wilth Visinalization, of the Intestlie withont Secondlary Diagnosis<br />
.Mliscellaneous Disease of the Intestine and Abdominal Lining<br />
with Vistialization of the Intestine with Secondary Diagnosis<br />
219 Miscellaneous Disease of the Intestine and Abdominal Lining<br />
with Major Surgery withoit Secondary Diagnosis<br />
220 Miscellahieous Disease of the Intestinle and Abdominal Lining<br />
with Major Sturgery with Secondary Diagnosis<br />
221 Ilepatitis. (l..lcetius. Sermni) Sualacute Necrosis of the Liver<br />
witil Age Icss thlsan 41<br />
222: lelpaltitis (Ihal¿etionss Seruis) Sblacuate Nierrosis ol'f the Liver<br />
witil Age grea.ter than *10<br />
223 I.iver Cirlhlosis withoílt Secoi;d.iry Diagainsis or with Slinor Secni)dar>'<br />
Di.agnosis<br />
224 Liver Cirrhosis with Major Srcondiary Diagnosis<br />
225 o:a..' of the Giallli;.Ider .atl btil Dc thi Sargry with<br />
Agre kh-, Ilsial 51<br />
226 1Ii:e,
C' .., MIX DEFINITION BY DRG<br />
Major Diagnosis Category<br />
53: Diseases of ~he<br />
Pancreas<br />
54: DcDiseases of thec<br />
Kidney muid Ureter<br />
55: Urinary Calculns<br />
56: Cystitis and Other<br />
Urinary Diseases<br />
57: Disease of the Prostate<br />
227<br />
228<br />
229<br />
- 84 -<br />
Diagnosis-Related Croiups<br />
Disease of the Gallbladder and Bile Duct with Surgery witlho1,<br />
Secondary Diagnosis<br />
Disease of the Callbladder and Bile Duct with Surgery with<br />
SecoMdary Diagnosis with Age less than 65<br />
Disease orfihe Callbladder and Bile Duct with Surgery with<br />
Secondary Diagnosis with Age greater than 64<br />
230 Disease of the Pancreas without Surgery<br />
231 Disease of the Pancreas with Surgery<br />
232<br />
233<br />
234<br />
235<br />
236<br />
237<br />
238<br />
239<br />
2.11<br />
241<br />
242<br />
¿MEDICAL C,,,M<br />
Disease of' the Kitdley aud Bladider witlhitit Surgery withi.ti Se
·. ¥XVIII. No. 2 Supplement<br />
)i, "'"<br />
, Major Diagnosis Category<br />
58: Disease of the Male<br />
" Reproductive System<br />
59: Disease of th.: Femiale<br />
Reproductive Systenm<br />
60: Diseases of<br />
the Breast<br />
61: Abortion<br />
62: Obstetricai Diseases<br />
of the Antpartilm and<br />
Puerperiuna<br />
63: Normal Delivery<br />
64: Delivery with<br />
Complications<br />
65: Diseases of the<br />
Skini anid Subel.lasiv ems<br />
'Tissue<br />
2,56 I)is¢i-se ol tih<br />
Prostate)<br />
Prostate with Surge
- 86 -<br />
CASE MIX DEFINITION BY DRG NMEDICAL CARE<br />
MIajor Diagnosis Category<br />
66: Arthritis<br />
67: Derangenment and<br />
Displacement of<br />
Intervertebral Disc<br />
68: Diseases of the<br />
Bone and Cartilage<br />
£9: Other Disease of the<br />
Mlusculo-Skeletal System<br />
70: Congenital Anonmalies<br />
287<br />
288<br />
289<br />
290<br />
291<br />
292<br />
293<br />
294<br />
Skin Inflammation, Abscess, Eczema. Reddened Skin with Sur.<br />
gery without Secondary Diagnosis<br />
Skin Inflammation. Abscess, Eczema. Reddened Skin with Suir.<br />
gery with Secondauy Diagnosis<br />
Psoriasis Eruptive Skin Lesions, Chronic Skin Ulcer<br />
Arthritis without Surgery with Age less than 65<br />
Arthritis without Surgery with Age greater than 64<br />
Arthritis with Surgery (Excision of Bone, Joint, Mlembrane Sur.<br />
gical Joint Fixation)<br />
Artha itis with Surgery (Juint Incision. Spinal Fusions, Excision of<br />
Tissue Between Vertebrae)<br />
Arthritis with Surgery (Repair and Restoration of Joint, Removal<br />
ol' Mitil>nllbm, Ixtwee.ii Vertelbrae)<br />
295 Disorder and Displacement of disc Between Vertebrae withouit<br />
Surgery<br />
296 Di:uorder and Displacement of Disc Between Vertebrae with<br />
Surgery<br />
297<br />
298<br />
299<br />
300<br />
301<br />
302<br />
303<br />
304<br />
305<br />
306<br />
307<br />
308<br />
I)iiuioisl~cl;I~tl Groitpn:<br />
Rheuimatism and Inflammaition Tissue Covering Bone, Other<br />
Minor Bone Disease without Surgery<br />
Disease of the Bone. Inflammation of Mlarrow (.Acite, Chronic).<br />
,'ungy Bone, Un.tided Fracture without Surgery<br />
Disease of the Bore. and Boine Tissue Lining. with Surgery (Excisioin<br />
Bolie Linitng, Repair ol' Other Joiunt)<br />
Disease of the Boae and Bone Tissue Lining witli Surgery)' (Jint<br />
Ihcision, Bone Excision, Bone Fusion)<br />
Disease of the Bone and Bone Tissue Lining with Surgery<br />
(Amputation, Hip Restoration. Other Major) '<br />
Inflammiaiition of the Component Parts of the Joints, Curvature of<br />
the Spine, Deformed Foot without Surgery<br />
Backache. Difluse Disease of Connective Tissue. Inflarnmation<br />
of Musele without Surgery without Secondary Diagnosis<br />
Backache. Difiuse Disease of Connective Tissue. Inflammation<br />
of Mlusele without Surgery with Secondary Diagnosis<br />
Inflanimnation of the Comipornent Parts of Joints with Detrmnity<br />
(Palm, Finger. 'oe) with Surgery<br />
Other Disease of the Muscle and Bone (Major) with Surgical<br />
Procedure<br />
()ther Disease of the' Muscle and Bone (lajor>:with Surgery<br />
(Removal, Repair of the Small Joint, Bone)<br />
Other Disease of the Muscle and Bone (Major) with Surger'<br />
(oining Vertebrae,. Other)<br />
309 Birth Defect (Bone. Stomnach, Testicle) without Surgery<br />
310 Birth Defect (Heart, Kidney. Other MSajor) without Surger>)<br />
311 Birth Defect (Testicle. Skin, Stomach. Other Minor) with Surgery<br />
312 Birth Defect (Heart Valve, Other Unspecified Heart Site) with<br />
Surgical Procedure (Cardiac Catheterization)<br />
313 Birth Defect (Palate, Lip. Hip or Other Extremity) with Surger>'<br />
(Repair of .Mouth. Fixatio of liip)<br />
314 Birth Detlct (Heart Valve, Other Unspecified Site) with Surgery<br />
(Heart Valve, Septal Repair)<br />
315 Congenital Diseases (Tetralogy of Fallot, Atrial Septal Deftect.<br />
Hypospadia, Other) with Surgical Procedure (Catheterization,<br />
Repair of Urethra)<br />
316 CoiCogenIitlil D)iscases (Tetralogy of Fallot, Atriil Septal Dei.ct.<br />
Other) with Surgery (Valve, Septum, Shunt)
- 87 -<br />
'i1. XVIII. No. -. Supplemnent APPENDIX<br />
Major Diagnosis Category Diagnosis-Related Grotips<br />
Normal blature<br />
Newbom<br />
1: Ccrtain Diseases aid<br />
Coulditiolns Peculiar<br />
to Nelhmxío Iniants<br />
13: Signis anMd SYnl)ptouns<br />
>Pertaiuing to the<br />
Nervous, Respiratory,<br />
and Circulatory Systemos<br />
74: Sign.s anud Synlptolms<br />
Pertainimng to the<br />
Castro-Intestinal<br />
and Urinary Systerms<br />
15: Miscellanelous Signs.<br />
Symptonms,i. und IlI-<br />
Defined Conditions<br />
?/6:' Fractures<br />
317 iirthil Deect (Spine. Cullet. Large Uowel) with Sturgery<br />
318 Normal Full Trmi Netvborn<br />
319<br />
320<br />
321<br />
322<br />
323<br />
32.1<br />
325<br />
326<br />
Wcll Baby Care (Preginanuy greater than 9 nmonths), Other Mlinor<br />
Disease or Condition nl' the Nevwhorni Inlifat<br />
Ihnmaturity). Hyaliit ne ite Disease. Other M;jor Disease<br />
or Co(dlition o the Ilnf.mt without Secondlarv Diagnosis<br />
Infiliatuirity. Hyaline Membrane Disease, Othler Major Disease<br />
or Conmdition of the Inilint witi Secondary Diagnosis<br />
mlicvatimit ifl' s Nervotis. Respiratory, Circulatory System Disease<br />
w itlihut Surgery witlihot Seconidary Diagnosis<br />
Convulsions. Fainting. Nosebleed, Chest Pain withoutt Surgery<br />
withl Secinidary Diagnosis<br />
lra iu I)iso rdlr ol' I)ixzin.ss. Shorti.ss (l' Brrea lth. (:ougiling u¡><br />
Bllasid \wtiout Sourgery switlh Secoindar. Diagnosis<br />
Indications of Nervous. Respiratory, Circulatorory Systen Disease<br />
with Surgical Procedure<br />
Indlications of Nervous, Respiratory. Circ'ulatory System Disease<br />
with lMajor Suirgery<br />
327 niudications ofCGastro-lntestinal. Urinary Systein Disease withouit<br />
Surgery withoit Seconuedary Diagnosis<br />
328 ludicíations of Gastro-lntestinal, Urinaiury System Disease withoiut<br />
Surgery with Seconclary Diagnosis<br />
329 Indications of Gastro-lisl.thnal. Urinary Systeia Dis.e¿ice wit1h<br />
Surgical Procedure (Visual laispection. Other)<br />
330 IIndications of C.astro-Intestinal. Urinary System Disease with<br />
Surgery (Abdonminal, Other. Major)<br />
331<br />
332<br />
333<br />
334<br />
335<br />
Sterility (Male, Female), Admission for Ohservation without<br />
Surgery<br />
Chemical Imnalance, Headache. Fever. Other ¡ll-Delined Indication<br />
of Disease without Surgery with Age less than 15<br />
Chemical Imbalance, Headache, Fever, Other Ill-Deflined Indication<br />
of Disease without Surgery with Age greater than 14<br />
Miscellaneous Indication of Disease with Surgical Procedure<br />
(Visual Inspection, Other)<br />
Miscellaneous Indication ol' Disease with Surgery (Abdominal<br />
Surgory, Removal of Uterus, Other Major)<br />
336 Fracture (Skull, Face, Forearm, Leg, Foot. Hand) witihout Surgery<br />
with Age less than 30<br />
337 Fracture (Skull, Face, Forearm, Leg. Foot, Hand) without Surgery<br />
with Age greater than 29<br />
338 Fracture (Spine. Rihbs. Bone of the Upper Arm) without Surgery<br />
with Age less than 65<br />
3.39 Fracture (Spine, Ribs, Bone of the Upper Arm) without Surgery<br />
with Age greater than 64<br />
340 Fracture (Thigh Bone, Pelvis, Multiple) without Surgery<br />
341 Fracture (Nose. Foreannm. Hand, Lower Leg, Foot) with Surgical<br />
Procedure (Closed Redluction) withouit Secondary Diagnosis<br />
342 Fracture (Nose, Forearm, Hand, Lower Leg, Font) with Surgical<br />
Procedure (Closed Reduction) with Secondary Diagnosis<br />
343 Fracture (Lower Jaw, Upper Ann, Ankle) with Surgical Procedure<br />
(Closed Reduction. Open Reduction of Face) without Secondary<br />
Diagnosis<br />
344 Fracture (Lower Jaw. Upper Armn, Ankle) with Surgical Proce-
ASE: MIX DEFIl'l'lTION BY DII(;<br />
,?: I)iant:atiouis ailL<br />
O)thler MIuscuIo-Skeletal<br />
Injuries<br />
78: Internal injurie..<br />
ofl thc Crailiiin. ('hest.<br />
aiad O()ther ()rgRan<br />
79: Ol)peln Vomim!.I -ind<br />
Supt>erlcial Injuries<br />
80: Bunms<br />
\ 1 ;it or 1 )i;tgs l »á ( :ai( -g§ 1 r<br />
81: Complications of<br />
Medicail and Surgical<br />
Care<br />
- 88 -<br />
I)iaR m~isis-l a·l;te¿tpe,,uI<br />
ReHductionl. External Fixationl. (ther)<br />
346 Fracture (Allkle. Leg Bones) %withi Suargery (Open Retudli.¡,<br />
External Fixation, Other)<br />
347 Fracture (Thiglih ioe. Pelvis) with Surgery> (O>pen HeduetFi.. I: E<br />
tenial Fixation. (Other)<br />
S148 'Fra.tur(, w¡ithi .\lijor Siurery (Aiiputation¡. Istoritiml ,,It 1h<br />
Joinit ()ther Major)<br />
349<br />
:.350<br />
:351<br />
352<br />
353<br />
3:54<br />
355<br />
357<br />
.358<br />
.359<br />
.360<br />
361<br />
362<br />
3i3<br />
364<br />
365<br />
366<br />
SF:I)L} AI. ( 'lti<br />
I)ishaati>íon (Shuliilder. Ell>ow. 'Wrist, Kiee). Spr.aits ,l<br />
Fuot. Hamnd) %w ithmt Surgery<br />
I)islo;atioi (Jaw. lil p). Sprain(s ( K Ceiw.. Sacrrouiiac. O)t lir t' r,;,.-,<br />
fitdl) \\ illthit Surii *-ry<br />
I)ishluÉllo u ( St itoulder. Elouw. I1hnl¡), Sl)riosi (El),w. `rti.-<br />
1la"ml) with Suiirger!<br />
Disliíhation (Ki(ve, Aukle). Sprains (Shioulder, Kinee. Anklce I Iu .<br />
Surgery<br />
I)isloeatiml (llip.. Multiplel. Spriains (liip. Saeroiliac. Othe.r 1')<br />
s¡isciiie
Vl. \'ll. No. 2. Sntiít'ult.uit<br />
M.l;ijr P)i;agntosis Caitvlgry<br />
'i1: Adversc EfSis et*1'<br />
:e.rtainí. Sl:st;]w. '<br />
$10 Special Admissimi.%<br />
itid Ei; sillIli¢11<br />
\\witllhot tlorte.d<br />
Diasguosst s<br />
Diagniosis-Reitlated (.:ropil.<br />
371 Comillic:ttioins of' IMedlicail or Surgiical Care with Surgical<br />
P o'( tt ed ll--- '<br />
372 (:Colpli;'t:lons 4,1' Sle i'Ial or Surgic;l (:.ir. withl Slrgtry n (Re.<br />
l hutu(tI t of' leart Devi¡e. Relpair of StoilaLh )<br />
.373 (.' :t)Ihiltinios of IMedival or Slurgicval Care with Sargerry (Ret<br />
sioi onf Slitint. O)thlir S;Ijor)<br />
37.1<br />
:375<br />
.376<br />
.77<br />
- 89 -<br />
APPENDIX<br />
A\dv. r% . I' l;;.tt ' .f I) >rug. 'l' .sxi Ell t. .t<br />
o
MANACGEIttI SC'IEN.'t<br />
Vol. 2Z. No. 4, F,-cemnhr. 197'<br />
Pr,*,t in C'.S.A.<br />
-90 -<br />
A COMPUTER SIMUILATION MODEL FOR THE<br />
CONTROL <strong>OF</strong> RABI31S IN AN UJ13AN AREA <strong>OF</strong><br />
COLOMBIA*t<br />
RAII'H R. FRI-tl CI¡S; AND JUAN PRAW §)A<br />
A siminulation itilItJl is develhq>ed Jcs.ribIing ihie itr:ai.llesiloll o ca ;iitic f;-lllsv: witvaill ;¿liJ<br />
between 116 spaiially distribuied barrios (ncighborhoods) in Calli Colombia. The discrete<br />
time. dynamic model considers both discrete randomni variables (incubation and infective<br />
periods. appearance and movemitent of rabid dogs through the city. ete.) and delerministic<br />
vatriables (Jc¡nogr:iphlic ouipuiluenis of harrio cainii¡ populalailions). V:hlties for tIh ilrnp<br />
variables were aequired throuigh field observalions, other Colombian sources. and a review of<br />
the literature. Vanriots caniine vaccinatlion slrategies were tested in the model over a Ien-vear<br />
planning horizon for liheir cost-cefeetiveness with regard to ihe prevention of canine rabies.<br />
The model is reommnended to ¡he l>an Amnerican Hlealth Organization lo he used a. an<br />
interactive gaminiug nilel to aid heali ll sysiClmli i;al:igers il (C'ali. C'thlolulia ¿aind inl otller l.;liiii<br />
American cities in seliedulilg I(he<br />
cost-effective mnanner.<br />
tine and locations of vaccination teams in a more<br />
1. hlilrOdtl¢mlion¡<br />
The problem of rabies has bcen with man for many years. Celsus. as far back as the<br />
first century A.D.. described the infection in man and observed that the disease is<br />
transmitted by the bite of a rabid animal. Since then. it has been shown that rabies is<br />
a viral infection of ¡he nervous systemi primirily of warm-bloolded aninials. anid is<br />
invatriably fatal once ¡ihe virus has infected the body 120]. 1331.<br />
In the last twenty years. the United States has rid its urban dog populations of this<br />
disease but the problem still lingers in wildlife. namely skunks and foxes [35]. Since<br />
man has his closcst conilct with urban animials. the climination of rabies fronm dogs<br />
has reduced human rabies in the United Sidtes lo one or two cases per ycar.<br />
Unfortunately. South anid Central American countries have not liad simiilar success<br />
[251. Since other diseases compete for allocations within the health budget, rabies<br />
control programis have not always rceeived ¡he funds necessary to climilnate the<br />
problem in urban areas (2].<br />
The World Health Organization feels that the vaccination of dogs is one of the most<br />
important methods for controlling rabies in cities and many immunization campaigns<br />
have proven thc efficacy of this approachi [41]. In addition. they recomnmend that stray<br />
dogs be euthanized in order lo decrease ihe canine density in the streets to such a<br />
point that there is little opportunity for rabies transmission. The collection and<br />
subsequent lilliidg of stray dogs. however, is highly unpopular as evidenced by the<br />
disdain shown throughout the world toward the neighborhood dog catcher. The<br />
assumption is made by the authors t. ,t in Colombia' a democracy with a history of<br />
internal violence, a caninc euthanasia campaign would be politically unacceptable.<br />
Therefore. the scope of our analytical effort'is liniited to a control program fcaturing<br />
different vaccination policies.<br />
Processed by Professor William W. Cooper, Departmental Editor for Public Aminiinstration and<br />
Associate Editor E. S. Savas: received Ociober 1974.<br />
t This research study was supported by the Tulane University Intlernational Center lor Medical Rcecarch<br />
and Training. Grant AI-10050 from the National Institute of Allergy and Infectious Diseases. National<br />
Institutes of Health, Unitei Siates Public llealth Scrvicc, Washington. D. C.<br />
: I.ouisiana Stale University Medical School.<br />
f Natiounal Company ol Basic ('omnoditicis (CONASUI>O). Mexico andt National Politemc lutie Institutc<br />
Mexico.<br />
. . Copyrtght £ 1975, The Institute of stani$;omcnt Sclencem
- 91 -<br />
R. FRIRICHIS AND J. PRAWDA<br />
When planning immunizíaiion programs for a given time period. the queslion arises<br />
as lo whlat percent of a population should he vaccinated and how often the immunization<br />
camplaiigns are to be repeated. Th'IelC rol ili of rabies transmission decreases<br />
when (ile number of inmmiunized dog.s in an area increases. lowever. if too few dogs<br />
are vaccinated. the risk of a rabies epidemlic will remnain higli. IEven afíer a successful<br />
vaccinalion prograi. tlile risk of a rabies epidemic will slowly starl to increase. since<br />
new susceptible puppies are boraI inIt> ile population and old immun e do.gs either Ldie<br />
or lose tieir immunity. Dogs in the poorer areas of a city have higher hirth and detahJ<br />
rales than dogs in wealthier sections. Consequenlly the rate of turnover fronm immuine<br />
lo susceptible varies fronm ncighlborlhod to neighlhorlhood, creating ovcr time a<br />
checkerboard erfect in wlúici<br />
outhreak.<br />
eacl arca hias a diferent probability of a rabies<br />
The problei facing tlhe heallh system manager is lo determine tile frequency andi<br />
intensity of vaccination campaignls which will maxiniize the cost-effectiveness of his<br />
control progr;ill in cvery section of a city throughlout hc pl;anii g hori,.ol. iII ordeil<br />
to do liis however, he musl hiave some idea as lo the number of rabid dogs which his<br />
policy prevents from occurring. The best policy is clearly tlhe one wic ni minimizes the<br />
cost per prevented rabid dog while mailtiining rabies helow a socially acceplable<br />
level.<br />
In the real world it is difficult and frequently impossible to estimate the exact<br />
outcome of a vaccination campaign. The inucidence of canine rabies is greatly<br />
under-reported, one reason being thail extensive laboratory tests are necessary lo<br />
confirnl or deny lie existence of tile discase. lI adidition. imalny people observe dogs<br />
suspected of having rabies but destroy them or allow them to die witlout reporting<br />
lie incident to the local health departmient.<br />
Maithematical discase modells are usually constructed in order to provide insight<br />
into ihle biological interactions necessary for tilr tra;nsmission of ille discase. Man) of<br />
the malhematical models reviewed by lhe authors (listed below) were found to be<br />
exceedingly coniplex witli no derived analytical solutions. Other miodels. altlhoughl<br />
elegan iii structure. may bc of very little use to health system managers who find<br />
themI diffiCulh Lto undersliand and, consequenlly. lo illolmplemeni.<br />
Among the literature reviewed. we list the following: historical review and state of<br />
lhe art [3). [41, [9], [101, {191. [29]: maihematical moudels of coinmunicable diseases [171.<br />
[22). [30:; recentc deterninistic disease models 161, 115], [21], 126]. [381-140]: stochastic<br />
disease moiodels 11 [31. [. [4. 11i11- 113: comiputer siniulation disease modells ¡61. 1I1. [121.<br />
[131, [211, [261, 321. [381-1401; anid disease control miodels [51. [181. 231. [271, [31[. 139j,<br />
140].<br />
It was felt tliat a simulation mlodel of urban rabies paiterned after real world<br />
processes would enable the manager tlo experiment with different policies and observe<br />
the resuliant outcomes. The knowledge derived from this approach should greatly aid<br />
him in making the quantitative and qualitative decisions necessary for controlling<br />
urban rabies.<br />
The purpose of Ilhis paper is first lo describe a simiulation nmodel for lIIe control of<br />
urban canine rabies lthat was developed for thc city ol' Cali, Colonbia. alan. secondl to<br />
conmpare 1ti cost-e'fectivetness of various simniulalted vaccination campaig!ns in order to<br />
recom nicnd )o the healtlll systlen manaitgers thill preferred policy which is the mos I<br />
efficient ani cffective amnong all policies tested using (ti model.<br />
In adeveloping the model. we first liad tlo define lile problemi and(l tIhn convert the<br />
¡;. blem into mathematical fornm. Estimates of tihe parameler value,- were derived<br />
from a review of the literatulre or from prior canine survevs co;: -c"ed ¡in Cali.<br />
Colonmbia. Crtatin v;alues. Ihowever were ,c'nobltaiable froai ilhese s ;t. tC.¢ id had lo<br />
be derived from field epc.rirnenis in Cait or estimated from exislitir IKowledge. The<br />
conimuter siniulation was tested cnl ihe IBM 7044 at Tulane Unive
- 92 -<br />
RAllIES CONI'ROL IN JURBAN COL.OMBIA<br />
One tic le odel was developed. two sets of vaccination policies were tested. The<br />
firns set consisted o`f ;iassive vaciinaltion campaligns at selected intervals whilh<br />
resilíted iii thie imuniiiizalion of 70 percent of lhe dog population inii a parts of ilhe<br />
city. T'ih second sel. which we refer to as lhe Preferred Vaccination Policies. invohled<br />
a SCies of exl erimn ¡s in whiclh dogs were vaccinated only in tllose areas of the city<br />
.tiat had l ile potlential to contributle Ilos (o tlle incidenlce .if rablies.<br />
In ilhe followin seclions we will describe the states and interactions of caniine<br />
rabies as defined ror the simulation model. The mathematical formulaltion will not be<br />
plresnteild here but can le fouiníd in the principa;l autior's doctoral dissertation 1141. In<br />
aidditioll. we will dliscuss ile differeLnt policies an¡ld dlhefcc effe lh polic! h;as on canillne<br />
rabies. At ¡he end wve will briefly meiluion ilc rabiíes control recommendallions which<br />
rwcre made lo ilhe Colombianl hCealh officiais and some of the problemis which arose<br />
wxlhcn ;tinlíptlini. ¡o deterlini e ¡lch valdliity of the nimodel.<br />
2. I)efinition of Ile IProblemi<br />
('ali is located iii soulhweslelrn Colombia and has a population of over 800.0R}0<br />
pecople :red al'lOiín;alely 84.000 dots. A sizeable portion of ile population is<br />
ilpoverished. wiilh oinly rfouLr prcentli of 1he i;aimilies having a Lotl co,hbil.ed ilicoí,ie.<br />
based on a 1969 survey. of more than the equivalent of 500 dollars per mon¡th. The<br />
poorer areas have dirt streets, and children and dogs are seen everywhere.<br />
I:or this model. tile city was divided into a spatial grid wiilh 116 neighborhoods or<br />
:.irrios. each harrio being arlproxinialely 50 lheetires iin size (one hectare = 10.000<br />
squarre meters). 1The assumnption is miade that; inieclious rabid dogs migrate stochlasticall<br />
hbetween harrios ani)d set off new epidemics in the barrios to which they hia\e<br />
iigr:led. TIhie susceplible and inillune dog-)s, as observed iii Cali. are assuiled to<br />
reinl:tin wilin tl heir specific barrios duringg lhe entire time period. Onlly a certaiin<br />
proportion of al! inl'ecld rabid doogs actually transinil the disease to oihers. If ilhe<br />
infectie dog develops the "furious' symptoms, he tends to wander aimilessly and bite<br />
al ;i lh;iteer crosses shis path. while if ilhe infection results in tlhe "paralytic" symiptonis.<br />
the dog beconies paralyzcd and is ineffective a dlisease transminssion 171. 1i ;addition.<br />
the rabid dog must lhave virus present in its saliva before ¡tie disease can be<br />
tranisinitied througlh a biie (361. It thce model. the number of rabid udogs exhibiting tihe<br />
furious symiptolis of lhe disease with virus ini their saliva is Lrelted as a discrete<br />
ra;ildoln variablc reseiliing from tiic encounter between wanídering-rabid dogs and ¡ile<br />
su.sce:ptillc do-gs living ill any giveni b;arrio. The sysleín is ;1 discrete time ímodel w\itll<br />
3.10ll) daily irllC¡ali(),ls 'eprcsenting rabies during a ten-year planning hori,.on.<br />
I'lc epideJioloLy ot f urban can;inlie rabies is dIascril)dl liagratini atically in I:igure I.<br />
Dogs in the rabies cycle cani he catcgorized into one of ile following. five. mutually<br />
;exclusive states: (I) Susceptible. (2) Immune.: (3) Incubatin- (4) Infective, or (5)<br />
.Dead. In order for rabies to exist in a city, changes must occur in the various states of<br />
dogs over tinmc.<br />
1 )ogs whicil iare in ic susceptible stale. .\. are thlose which have never been<br />
v;tccainlled C:iaillns rabies or those whlich have been vaccinaled bul hatve subsC.etiiul¡ly<br />
lost their iniii il.iv. ()nce a proportion, t. of thie susceptibic dogs are vaccinailed hley<br />
becom
- 93 -<br />
414 R. FRRKICkIS AND J. PRAWDA<br />
Birthrote<br />
Birthrate<br />
Population c b<br />
SG. uscept G bil / Tmm nu<br />
X Loss of Immunity Rote Z<br />
Contact /1 proportion vaccinated<br />
Incuboting<br />
Incubotion Incub0 ao<br />
Period persod<br />
Wildlife Infective<br />
Inmmigrating PeriodM<br />
Robid<br />
Dogs<br />
Death A<br />
F¢iouir I1. Epidicmiolo.ical model of inieractions and states of canine rabies.<br />
if an infective dog has adequate contact with a susceptible dog, the susceptible<br />
becomes infected with the rabies virus and is moved to the incubating statc. H.<br />
Adequate contacl means that a rabid dog with virus in its saliva has bitten a<br />
susceptible dog enough times to '-ansmit the discase. Therefore. tlhe probabiliiy of a<br />
new rabid dog is dependent on the number in the infective state. Y. Y the nlumber in lhe<br />
susceptible state, X. and the rate of contact, B, between tIem.<br />
Once a dog is infected with rabies, it goes through a variable length incubaUion<br />
period. The length of stay in the incubation state is determined by a number drawn<br />
randomly from a log-normal frequency distribution which has a mean and variance<br />
characteristic of the incubation period in the real world [7]. [281. [33]. Only the<br />
proportion of rabid dogs which are in the furious symptomatic stage with virus in<br />
their saliva are consídered infective. The other rabid dogs. either tliose in the paralytic<br />
stage or those with negative saliva. are assunied inol to be involved in the transmission<br />
of the disease. Instead, they move direcily to the dead sate, R.<br />
All rabies infected dogs cventually die, since the recovery rate is assumed to be<br />
zero. Once in the infective state, Y, the rabid dog remains infective for a variable<br />
length of time. The length of stay in the infective state is determined by drawing<br />
randomly a value from a log-normal frequency distribution which has a mean and<br />
variance characteristic of the infective period derived from clinical observations [20].<br />
1341. 1361.<br />
While in the infective state, Y. the rabid dogs may wandesr htiroughiout the city. The<br />
tendency to roain is a characteristic of the furious phasc of the disease. Everyday<br />
thiere is a certainl proba-hility thai rabid (logs will remain in the area where thev' are<br />
preselilly locatecd or Icave and imove to al.djacent barrios. Only one potential move is<br />
allowed per day. Figure 2 illustrates the movenicis of raibid dil ,s heweenl barrios.<br />
The probability. g. that infectives leave a barrio, is dependen¡ on swlhere they<br />
,ariíinated and whece they are going. For the simulation model. each day's movemients<br />
are hindled in au stochaestic m;iliner. l'i:tcl rabhid dog is given tlie (dily' oplion. if still<br />
alive, of remaining stationary or moving to one ol' I'ive neilhborig barhriios.,. After<br />
entering a r.-w barrio. ,he infective dog interacts with the susceptible dogs in thlat
- 94 -<br />
RABILES CONTIROL IN tURIAN COLOMBIA<br />
IMMIGRATING RABID DOGS<br />
ISNS SUS g<br />
sus sus RABID<br />
SU SUS SUS SUS--WLDLIFE<br />
SWILDLIFE<br />
sUS<br />
RABID . 'SUS S U s SUS<br />
WILDLIFE T<br />
4SUSSUS S US<br />
IMMIGRATING RABID DOGS<br />
FIoURE 2. Movement of inective rabid dogs and wildlife into and through a spatial grid representing<br />
an urban area. Abbrev.: INF - infeclive rabid dog. SUS - susceptible dog. g - probability of movemenl in a<br />
given direction.<br />
barrio and possibly, depending on the amount of contact, continues the transmission<br />
of the disease.<br />
A certain number, W, of rabid wildlife (see Figures I and 2) enter the peripheral<br />
barrios of the city and interact with the susceptible dog population. The wildlife are<br />
given the opportunity to make only one move since it appears likely that a wild<br />
antimal would be killed before it could roam very far in a city. Once in tihe urban area,<br />
the rabid wild animals are included in the infective state, Y.<br />
Urban canine population growth, G, in every barrio (see Figure 1) is assumed to be<br />
proportional to the human population growth in that barrio [37]. The assumption is<br />
also made that these entering dogs are not vaccinated and therefore increase the<br />
susceptible canine population in a specified barrio by G. per day. Some of the newly<br />
arriving dogs may have had contact with rabies outside the system and be currently<br />
incubating the disease. A certain number, M, would become part of the infective state,<br />
Y, during the year (see Figures I and 2). The probability that they will appear in any<br />
specific barrio is dependent on the proportion of the city's human population<br />
presently living in that barrio. The assumption is based on the idea that the more<br />
people there are in an area, the greater is the chance that their dogs will have had<br />
some interaction with other dogs in surrounding areas or cities where rabies currently<br />
exists.<br />
The model accepts as inputs the vaccination schedule. the number of vaccinating<br />
teamnis and trucks, and tlhe numher of rabid dogs anid rabid wildlife which enter ealch<br />
year fromi outside tihe system.<br />
3. Exsperiteicnts Usinsg itLe Model<br />
Since ti,e model is stochastic. numerous epidemic trails were run per experiment in<br />
order to determine thc mican numbcl cunmulative rabid dogs atl he end of o íevery<br />
year. All costs mentioned in the following sections are estimates. based on Colombian
- 95 -<br />
R. F'RERICItS'AND J. PRAWDA<br />
data, of what each vaccination campaign would cost if the experiment were done in<br />
the rcal world.<br />
Rather than presenting frequency distributions derived froni multiple epidemic<br />
trials per experiment, we will deal only with mean values. The policy of no vaccination<br />
and the policy of 70 percent initial vaccination were the only ones which<br />
consisited of 100 epideic trials per experiment. The results from all other tested<br />
policies are based on 10 epidemic trials per experiment.<br />
3a. A Single 70 Percent Vaccination Catmipaigtn<br />
Looking only at the niean nuiiber of ca;nilti rabies cases per year, Figure 3<br />
indicates that the policy of 70 percent initial vaccination was able to reduce the yearly<br />
incidence of rabies for approximately five years. Thereafter, the yearly incidence of<br />
rabies was greater than ii vwe had followed the policy of doing nothing at all (no<br />
vaccination). With rabies absent froni a barrio. the dcnsity of susceptible dogs and the<br />
concurrent likelihood of a rabies outbreak increased. All that was required was for an<br />
infectious rabid dog to wander by chance into the barrio and trigger a new epidemic.<br />
This same plhenomenon of a disease being kept out of an area and then suddJenly<br />
appearing in an epidemic fornm lhas bcen frequently tobserved iii the real world with<br />
rabies as well as with other infectious diseases [161, [24].<br />
Comparing after ten years the cumulative mean nuniber of rabid dogs in the<br />
absence of any control policy and the value with an initial 70 percent vaccination<br />
campaign, we see in Table I that thc immunization program prevented 2.985 rabid<br />
dogs (21.588 minus 18.603). The theoretical vaccination campaign, however. took 85<br />
daily iterations to complete and required the operator to assign 48 vaccinators<br />
traveling in 8 trucks to all barrios of the city. During tcse three months. 59.323 dogs<br />
were vaccinated. Taking into accounti the cost of wages. the use of the trucks. ihe<br />
4000 - 70% ni/h/v. va<br />
40001<br />
/70% initol'tl iac.<br />
o 3000- 70% revac. 5J<br />
No vaccinat/on<br />
2000- 1<br />
%I0 0 ,Preferred ¡<br />
vac.<br />
',~:~ _ .'opo/, y(V4-va-7O YJ<br />
I 2 3 4 5 6 7 8 9 10<br />
Year<br />
FiLGUR 3. Compuier Simulation Experiments: Comparison of the mean number of rabid dogs per yecar<br />
,t.ri;nc a ten-year period with policies of (I) no vaccination (mean, 100 epidemic triais). (2) initial 70 percent<br />
vacciration (mean, 100 epidemic trials), (3) two 70 percent vaccination campaigns. one a tihe beginning and<br />
the other after 5 years (mean, 10 epidemnic trials), and (4) the Preferred Vaccination Pulicy with VA sei al 70<br />
percent (mean, 10 epide.a.: irials).
- 96 -<br />
RABIES CONTROL IN URBAN COLOMBIA<br />
TABLE 1.<br />
C'onpuiter Sinudlaion Experiotnems: Comiparison of four wa¢cinaslion policies, orer a ten-.eur period.<br />
ita h rcgtrI tll s tllo' s¿ntil l l.¿tllt ti'¢' ,Ii lhl' r (If rlifld dogsx. th', flteel rct .luit*l' r of cci rsted dt>gs. oi¿d<br />
¡he cosi vj ¡he inditiduúal policies.<br />
Cost (dollars)<br />
Number oí Mcan<br />
Cl)idenilli toh l Iper ra.bid<br />
trials per rabid Total dogs per dog jdog<br />
Vaccinatiun policy experiment dogs vaccinated Total' vaccinated prevented<br />
No vaccinaitioi<br />
70%' initial vacciniation<br />
1¡00 21.588 O 0 0 0<br />
(entire city)"<br />
70% iniiíal vaccination<br />
70{P, ftvaccinatioin (yr. 5)<br />
100 18.603 59.323 22.157 0.37 7.42<br />
(;sir¢ ciíy)~'<br />
'referrcd Vaccin:aiun<br />
ISC 7.71 I 139,638 60.8 , 0.8.,1 .1.3.1<br />
Policy (VA- 70%')'** 10 3,197 100.282 64.982 0.65 3.53<br />
'lic os( of vacciniation is annually increased by an inflation factor of 5 percent<br />
·* Thie simuliated camupaign took 85 days and required thlc use of 8 trucks and 48 vacem-lt;ors.<br />
*'· The initial simulated campaign took 85 days and the second simulated campaign. due to<br />
the canine population growth, took 112 days. Both campaigns required the use of 8 trucks and<br />
4S vaccinators.<br />
'' The policy ;cquired the continuous usc of I truck and 2 vaccinalors.<br />
Rabies Control Center, and the unit cost of the vaccine, the 70 percent vaccination<br />
campaign theoretically cost the administration 22,157 dollars. The cost per prevented<br />
rabid dog is calculated for the len-ycar time period as 22,157 dollars divided by 2.985<br />
prevented rabid dogs or 7.42 dollars per prevented rabid dog. The question lhen<br />
arises, '"Can the health system manager do better with a different vaccination policy?"<br />
3b. Two 70 Percent Vaccination Camnpaigns<br />
It appears obvious that a second 70 percent vaccination campaign at year 5 would<br />
be very beneficial. Figure 3 compares a policy of one initial 70 percent campaign<br />
versus a policy of two 70 percent campaigns, one initial and one at year 5. The double<br />
campaign reduces rabies for about nine years before there is an epidemic.<br />
The cuos of the double camrpaign. as seen in Table 1, is almost triple the cost of the<br />
single campaign due to the increase in both the city's canine population and thc cost<br />
of labor, supplics, etc. associated with 'a five percení' annual inflation rate. The<br />
cost-per-rabid dog prevented. however, is greatly decreased due to the sizable reduction<br />
in the mean cumulative number of rabid dogs.<br />
3c. Preferred Vaccinaoion Policy<br />
In order to reduce further the incidence of rabies, we developed an alternative<br />
policy which continuously employs throughout the planning horizon two vaccinators<br />
traveling in one truck to various selected barrios. We refer to this control policy as the<br />
Preferred Vaccination Policy since wc felt i. was the hest among all tested policies. A<br />
formitiil for the Prefcrred Vaccination Policy was developed which ranks each barrio<br />
accorditng Lo thc potenti[il conuilibution it would miake to ¡Ihe inicidence of c;nine<br />
rabies. The risk of contributing to new rabies cases is calculated for each barrio as<br />
follows:<br />
j-_
- 97 -<br />
R. F'RRICHS AND J. PRAWDA<br />
where<br />
R,.,= thc index of rabies risk for a barrio i at time i,<br />
C, = hc relative proportion of barrio i dogs typically found in ihe streets.<br />
X , ,=the number of susceptible dogs in barrio i at time t, and<br />
i(j)=a subscript denoting neighboring barrios j,j= I ... 5 which surround<br />
barrio i.<br />
Since a rabid dog moves fromi barrio to barrio. the assu miiinIon is miade tlha tlhe sull<br />
of the values of Cq(,)X,(), in each of the five neighboring barrios is equally as<br />
important to the subsequent generation of rabies as the value of C,X, 1, ini barrio i<br />
itself.<br />
All values of R,., are ranked froni highest Lo lowest. A vaccinaling teaim aild truck<br />
are sent to thi highliest ranked barrio. II tiher are numerous trucks, each one goes to a<br />
separate high ranked barrio and remains there until the required proportion of<br />
susceplible dcogs is vaccinated. Thereafcíer the trucks return at diffrcent timc periods<br />
to the rabies center for reassignmieni to tle next highest raniked barrio. Tlhe most<br />
important factor is that the vaccinators go house-to-house in the selected barrios and<br />
vaccinate all susceptible dogs they encounter. Since the necessary informnation for the<br />
formitula can be continuiously updated hy tile vaccinators with limited data collected<br />
during their visit to the various barrios, we feel thlat the policy will be easy to operaite<br />
and will require little supervision. Further details of this barrio ranking procedure are<br />
published elsewhere (14].<br />
Thc Preferred Vaccinaltion Policy is co*mpared in Figure 3 with a policy of no<br />
vaccination. The term "VA" refeis Lo the fact that 70 percent of tihe susceptible cdogs<br />
in the selected barrios were immunizei durIn; each visit by the vaccinators. Or<br />
restated, it means that 30 percent of the barrio dog owners were either not home or<br />
were urnwilling to cooperate with tl - rabies prevention prograni. As can be seen in<br />
Figure 3 the Preferred Vaccination Policy greatly reduced the incidence of canine<br />
rabies throughout tihe planning horizon. But al wiiat cost?<br />
Comparing the three vaccination policies which we have shown so far. Table 1<br />
in¡dicates that thc Preferred Vaccination Policy with 70 percent public cooperation<br />
cost more than either of the otlher two policies. However, the cuniulative meanll<br />
number of rabid dogs over the ten-year planning horizon is also reduced to a lower<br />
level than either of the other two policies.<br />
PREFERRED VACCINATION POLICY PROBLEM<br />
80- n<br />
70 1 - MEAN<br />
60- Ki .95 confidence interval<br />
50- 1<br />
4 40-<br />
30<br />
20O<br />
Q. 10 __....._______ _-<br />
2 4 6 8 10 12<br />
COST(USAdollars) per PREVENTED RABID DOGS<br />
FIGURI: .1 ('omlpuler Simulalitn Experitmcnls: Cost ¡..r prevented rabi do<br />
dd Juring a ten-ycar rc,<br />
with the '-ilerred Vaccination Policy sel at diffcrcnt i.:vels of VA (percent vaccim;ted in ach .lv,<br />
barrio) (m,':;;. 0.95 ?cfidence interval, 10 epidemic tr!:is per experiment).
-98 -<br />
RABIES CONTROL IN URBAN COLOMBIA 419<br />
The usual indicator of a programn\'s success is the cost-per-dog vaccinated. We feel<br />
that this is a poor indicator since the objective of a rabies control program is not to<br />
vaccinate dogs but rather to Jecrease the incidence of canine rabies. Consequently the<br />
cost-per-rabid dog prevented should be the correct indicator. As is seen in ]'able 1. the<br />
Preferred Vaccination Policy with 70 percent public cooperation cost the niost per<br />
vaccinated dog but it cost the least per prevented rabid dog.<br />
An additional feature of the Preferred Vaccination Policy is that it is fairly<br />
insensitive to the percentage of barrio residents being home or cooperating. We<br />
selected VA (the percent of the susceptible dogs in a barrio that are available for<br />
vaccination) to equal 70 percent based on prior knowledge of participation rates for<br />
immunization campaigns. However. even if the estimate is in error. when VA is<br />
decreased in multiple experinients from 80 to 10 percent (see Figure 4), the theoretical<br />
cost-per-prevented-rabid dog for the Preferred Policy does not go up dramaticallv<br />
until less than 30 percent of the susceptible dogs in a barrio are available for<br />
vaccination.<br />
4. Validity of tile Model<br />
Before concluding. a brief niention should he made concerning the valiJity of ihe<br />
model. The problem of determining the validity can be analzed i in to wta)s. The<br />
first deals with iniernal validiti. Does ihe simulation model perforn iii the manner it<br />
was intended? We feel that the internal validity of the model should be very high since<br />
the compuier program was repeatedly tested and "debugged" during the initial<br />
construction of the moJel.<br />
The problem is with the external validiity. The question. "Does Ihe modell tell what<br />
i. occurring in the real world?". is more lifficult to answer. What we wuuld liike to do<br />
is he able to predict future happenings. lowever. since tlis is a new simul:a model ion<br />
which has never heen tested for predictive accuracy, all we can do is subjectively<br />
evaluate it to see if the results appear logical. Therefore, instead of external validity,.<br />
we will consider only if the model is or is not reasonable.<br />
Based oun our knowledge of rabies in general antd canine rabies in ('ali. lhe model<br />
Joes appear to be reasonable. An opportunity to compare the computer model o(utput<br />
wilh results in the real world occurred in the summer of 1971, wlien more than 80<br />
percent of the known dog lopulaUion ií' Cali was immunited by ¡he l:an Anierican<br />
ilealth Organization. The reported monthly incidence of canine rabies quickly<br />
dropped from more than 20 to less than 5 cases per month and remained at this level<br />
'or at leasl one year thereafter in spite of the fact that there was increrased rabies<br />
surveillance. This finding is in accord ¡itih the observations made using the simila:;on<br />
mnoel. A further discussion ot this point can be found elsewhere 114).<br />
S. Concluniuon<br />
l'le resulis of the simul;ation experiments indicate that a single vaccination<br />
campaign which immunizes 70 percent of all dogs in each hbarrio of ('Cali will maintai<br />
rabie:: :, a minimal level for five years. During the ten-year planuiing horizon. a policy<br />
involving two 70 percent vaccination campaigns (one *every five years) is more<br />
effective per unit cosí in reducing the cumulalive number of simnulated rabiid dogs<br />
than a single campaign during the same time period. The Preferred Vaccination<br />
Policy. utilizing information about the dog population in the city in order to identify<br />
high risk barrios for selective immunization, resulis in the lowest cost--per-prevented<br />
rabid dog.
- 99 -<br />
420 R. MFRIlC}IS AND J. PRAW)A<br />
The comnputer silmulation nmodel is recomimended lo the Pan American Hcalihi<br />
Orgain/,aliomi ciilich tIo lelp formult;icte va;icci;iollimn strategies for C;ali. oi r lo<br />
serve ats ati illt;iactlie teaclimll or' 1.ítiili$ míodel lo be Lused dlturin (lcil antitia; l c;lass<br />
on rabies control. As ;L llil .of1 experimenlaion wilh tile mn'odel. hcJlh svslemn<br />
mna;ll'agcrs shliu:ld learn to ;tppieciate the onlplcxity í)f tle systeim and derive grealer<br />
im.iiIhl t111> tle ecvenllt; ctntrol of til':til rahcles.<br />
Ríc;creces<br />
1. AaI:Y. Ilil.l:N, "An Examiiianon of ihe Reed-Frost Theory of Eplidrnies," litann BiGlaog.. Vol. 3<br />
(1952). Pp. 201-233.<br />
2. Al.BA, Il. As AcI Ai. 1>., "1TheC Stalus of Rabiehs in the Amriclas." 'S¥tol Ucri¢'l/t Ihler-.Il .lteting oit<br />
IWcoot-gal-nMaluh D.t,
- 100 -<br />
26. RLVEL.LE. C. S., LY\'N. W. R. AN;I F£L.DlIAS%. F., "Mathematical Models for ihe Economic Allocation<br />
of Tuherculosis Control Activities i<br />
89>3 909.<br />
e)cvcloping Nations." Am. Rcy. Resp. Dis.. Vol. 96 (1967). pp.<br />
27. - , I. I)MAN, 1:. ANí> 1.Ys. W V,. "Al l ()ltialiioIaI. Moledl al ílmcl'c ulm mñs I.pld¢llllmol:.m"<br />
/%Imt¡l'114'1{ ,S('i('11' Vol. 16 (Y(1')>. pp. 190 21 1.<br />
28. ailll, ( C'lARI.E. (.'., "l{mle.." il ('1úilt' Al4diclu . AIe¢isc.i.T Vetcrtsiary i'uTll . ¡hilg 1 . a..1ta<br />
Blarhar;a. ('al.. 19(2.<br />
29. ......... .I(ul:K I-I ;ohS<br />
145-166.<br />
"`h rt,.cl K{ cImw mnl p'pldmm c i'm'l'hc.i y* JI laum fIh.l, .I, Vo ?4 -1 (1 '.2>. pp.<br />
30. - , "Methods for Current Statistical Analysis of Excess Pneumonia-Influenza Deaths," Public<br />
Health Reporis. Vol. 78 (1963). pp. 494-506.<br />
31. TAYIOR,. I-lowAII<br />
pp. 383-398.<br />
M. .. Somie fmlcdls i¡n Epidemic Control," AMtrlmenlical /iu.c¡ieie. Vol. 3 (1965).<br />
32. TAY.Oit. WIL.LA,' F.,. "Some Monte Carlo Metlhods Applied lo an Epidemic of Acute Respiratory<br />
Disease." Iltunr Bialogr. Vol. 30 (1958). pp. 185-200.<br />
33. TiERKiE.. ERNEST S., "R.abies,"<br />
Springficld. II1.. 1'93.<br />
in Discases Tralsmitted from Animals iu Mun. Charles C. Thomas.<br />
34. - . "'Rabies." in (urreost Veeriurp, 'liherapl. 1966-67, W. U. iauijcrs Co.. I'lmilicl¡phai. 19d6.<br />
35. U.S. DEPAR'rMEN'I <strong>OF</strong> HIALT'Iit. EDUCATION, AND WEILIARLk, Morbidi, anid Muronilitr Aaittl Suple.<br />
ment, 1971, Center for Disease Control, Atlanta. Ga., 1971.<br />
36. VA'uIIN. J. B.. Gllzr^%Rnr. P. ^AN) NlaeI:I.. K. W., "Excretion of Street Rabies Virus in the Saliva of<br />
)Dos.". J. Am,:. MAI. Assm... Vol. 193 )(65), P).. 363 .368.<br />
37. VILLA)II:.Oo, FRANCIS(O. "A Two Percent -lousehold Survey Sample of Cali.," Universidad del Valle.<br />
38.<br />
Cali, Colombia. 1968-1970 (unpublished data).<br />
WAALER, H. T., "A Dynamic Model for the Epidemiology of Tuberculosis," Am. Rec. Resp. Dis., Vol.<br />
98 (1968), pp. 591-600.<br />
39. -- as I¡'o'r. M. A.. "Thc Use of an Epidemiological Model lor L.stimatini the EffecLivcness of<br />
Tuberculosis Control Mcasures," Biulletin Worhl lhealth Orgauni-:acion, Vol. 41 (1969). pp. 75-93.<br />
40. - - .AI' , "Use of an Epidemiological Model lor Estimating the Effectiveness of Tuberculosis<br />
Control Measures," Bullesin World Health Organization, Vo!. 43 (1970), pp. 1-16.<br />
41. WOKi.L IIFAI.TII ORGrANIZATION, I¡Y. I. OO. Expert Comnmitee on Rabies. Fifth Report. Technical Report<br />
Series 321, 19')66.
V<br />
- 101 -<br />
McUCi. (:Au<br />
AWuu IMI. VoL XIX Na. o<br />
The Case-Control Method in<br />
Medical Care Evaluation<br />
SA&n~ GCEeW.N.u M.S.. Da.P.H.,. EuCA, WáTmúON, M.D., M.P.H..t<br />
ND iLtrYOND R Naurm, M.D., DaP.H.<br />
Th. s~ meod esl belnu aplied euemively to he study .ocbomeic<br />
d~ lly be.sus éilts s¿dvm
VoL XIX. N. a<br />
- 102 -<br />
f tdie outeonie of interest delries two<br />
distinct categories (lfor exunple, death versus<br />
surival). outcome rates in different<br />
groups can, in theory, be compared by the<br />
case-ontrol ("retrospective") method." ' & '<br />
This method inivolves the election of a<br />
series of earso (btho~ persons experiencing<br />
the outo«me event) and the selection of a<br />
reference series ofnoncases ("onrols" or<br />
"referents") for comiparison to the case<br />
series. Vasious itaitica4l techniques allow<br />
estimion of differences in outiom occurrence<br />
between groups based on the<br />
cae-onatwl data'-provided the casecontrol<br />
study satisfies certain conditions<br />
requised for the validity of results. A primary<br />
advantage of the case-control method<br />
is that the number of subjects necessary is<br />
usually much les tan that required for a<br />
prospective comparison.' In the monitorlng<br />
exnple, a cas~o ntrol study would<br />
require fewer than 400 deliveries (200<br />
cases and 200 controls) to detect a 50 per<br />
cent reduction in the neonatal death rute<br />
due to monitoring with 90 per cent probability<br />
(power), at a 0.05 significance level t<br />
(assuming a 50 per cent monitoring rto in<br />
the target population).<br />
More than 20 yean ago. Cornfield and<br />
Haenszel' summrized the two critical<br />
represmntativeness' conditions that were<br />
thought necessary for the validity of a<br />
cse-control study: 1) it should be "possible<br />
to enumerate all new cases of a disease.<br />
or a representative sample of them, without<br />
haviig to doserve all the isdlviduals ¡i<br />
the population"; and 2) "the sample of individuals<br />
not developing the dierse ithe<br />
contrulsl Ishould supplyl an unbiased estimrte<br />
of the prevalence of the chtraceristic<br />
under study among the entire nondiseased<br />
population of interest. The authors<br />
then went un tu lamuint that most retrospective<br />
studies of dtit day had dificulty<br />
assuring the saislacwtion of the seond reqOtler authors of<br />
that period put forth simnilar criteria.u'<br />
More recent writers have cxpressed related<br />
criteria lor the validity oícal-cmotrol<br />
CASEV-COXNlTOL MTHOD<br />
resultl in a samplinig theory fraunework,?<br />
while other authors have rejected representativeness<br />
criteria and ilnstead have<br />
empha>sized the importance ofcompanbility<br />
ofcases and controls." A conimon feature<br />
of all these points of view. however. is<br />
un emphasis on the importance of "section<br />
validity" in casfcontrol studies, in<br />
that subject selection should be unbiased<br />
in order to achieve valid results.<br />
aIn the time since the early commentaries,<br />
genend resevatioa s onceming the<br />
utility of the caa.control method have<br />
been put forth, largely o the grouds that<br />
representativeness or selection validity<br />
conditions ar difficult to fulfll or auure in<br />
ordinary practice." Thbe purpose of our<br />
commentary is to offer an appreciation of<br />
the particular suitability of the case-control<br />
approach for many problems in medical<br />
cae evaluation. We will discuss why the<br />
clasic problems of selection validity are<br />
frequently absent in medical care evaluation<br />
settinr. and how odither common problemns<br />
ofordinary case-control resarch will<br />
often be miimizod as well.<br />
Coalidera~ Favorina the<br />
CaM-Cotil Method in .<br />
Evaluadon Sem~is<br />
bepresenaatveanrs ad Se~oo<br />
Co.sldodnlooe<br />
A menlioned above, problem of selection<br />
bias and subject nonrepresentativeness<br />
haive loed o a curin degree of dinstrus<br />
ofl s-control methods among many clinical<br />
researchers. Yet it is precisely in the<br />
realm of preliminary comparisons or<br />
evaluations of medical care or medicld<br />
teehnology tht the -control metdihod is<br />
most often immune to such problems.<br />
This is because many evaluation setting<br />
involve amall, well-defined turget populabions,<br />
such as a hospital inpatient population<br />
or several co¡nbsied hospital pupulations.<br />
In such settings it is usually possible<br />
to enuumeraite the entire target population.<br />
selecL representative wmlples froinm hud<br />
a
GREENLAND ET AL<br />
- 103 -<br />
the case (pa>tient experiencing Olutcom)ii<br />
mid noncase (p;tients without oitotaíole)<br />
groups, and thus avoid tdihe problemis of<br />
nonrepresentativeness and classical selection<br />
bias. Often, the target population will<br />
be enumerated in advance.<br />
Aallyssi C4oUdersiion<br />
Because of the lrequent paucity of infonnation<br />
regarding the absolute disease<br />
rates in the target or source population,<br />
classical (etiologie) applicationis of the<br />
c;se-control method have placed strong<br />
emphasis on the odds ratio (or fu¡ ;ons of<br />
it) in the analysis of case-control data." - '<br />
Many (if not most) problems in medical<br />
care or tecínology evaluation. however.<br />
require assessment of ellects in terrms of<br />
differences in exposure-specific rates,<br />
especially if risk-benefit analysis is required.<br />
s Furthermre, the use cf ratio<br />
mneasure without reoerence to uniderlying<br />
rates is inadequate isn most evaluaticn settings.<br />
For example, to say that a treatmnent<br />
reduces the odds of death by a factor of 20<br />
(an odds ratio of 1120) would be equally<br />
true if it reduced death risk from 90 per<br />
cent to 31 per cent or lrom 0.1 per cent to<br />
0.005 per cent; yet a high risk of senous<br />
side effects from the treatment would yield<br />
vastly different implications in each instance.<br />
Thus, the emp!hasis on odds-ratio<br />
analysis may be seen as another drawback<br />
of the case-control method. Fortunately,<br />
when enumerations of the target popula-<br />
',i ation and die cases are available (as is frequently<br />
tdie case in evaluation settilngs). the<br />
absolute exposure-specific rates can be estimated<br />
using Bayes' theorem,' and classical<br />
case-ontrol uanalysis methods can be<br />
deremphasized. Thus, the existence 'of<br />
soiil, well-delined target populations in<br />
evaullatiol settings provides analytic bene-,<br />
fits in additioín to validity assurancii s.<br />
Ajl Exiamiple: A Comparison of Neoiautl<br />
intestuive (Care Unilt<br />
Wae will ll hlustralte tile ailtve aud latL r<br />
p)ilmiNs withi aU exaip>le riolll Osir (OwiI ex-<br />
MWruCA CU<br />
perientce, a study recently carried out to<br />
4cmilpamre tle perlimniuiace of two diíilrent<br />
neonaatal intensive care units (NICUs).<br />
This study was an investigation of preliminary<br />
statistics indicatinLg an elevated death<br />
rate .amollg infant admintted to one of the<br />
usits (herealter designated unit A). A seeornd<br />
unit (lereather designamted unit B) serving<br />
a difierenit geographic region within<br />
the same health camre system was choseli as<br />
the comparison unit. Both units served<br />
low il5ciin, populaltio s ii tihe samle t¡ietropolitan<br />
urea, with no special referral jplan<br />
between the units. A randomized trial was<br />
clearly impractical. Ofprimary interest was<br />
whether the elevated death rate at unit A<br />
ciuld be explaisaed solely as; a restult of<br />
chalice, or as being due toi ana elevated proportion<br />
of high-risl infants being adminted<br />
to unit A. Ifeitherexplanation turned iat to<br />
be correct, a costly investigative comparison<br />
of quality of cure in the unit coulil be<br />
avoided.<br />
Civen various practical considerations,<br />
total samile size was limited to approximately<br />
200 intfants. Based on an initial estinate<br />
of the death rates in the units. only<br />
25-30 cases (neonatal deaiths) would have<br />
been expected in a prospective study<br />
based en a simple random sample of 200<br />
admissions t tthe NICUs. This was judged<br />
to be an insuflicient number of caseá to<br />
accurately assess the role of vanaous risk<br />
factors in die units. Furthermore, the admissions<br />
to the NICUs (tlte target population)<br />
were conmpletely and continuously<br />
enuminierated, anl thie status of admittees at<br />
28 days Rlier birth (aliveldead) was always<br />
determined. Given these consideratiois, it<br />
was decided that a case-control stuldy<br />
wouid be conducted íimom medical recotrds.<br />
(>ver a specified period of time, all NICU<br />
adUilissions that eunded in a neoinatal death<br />
woild be entered in the stiidy, along with a<br />
50 per cent randomn sumple of tie neoiaital<br />
sxlrvivors fiom the same target population<br />
(mliít A + asmit B). (Muiltiple births, i intsn<br />
uiader 800 gt mris hirtiiwt!ilght or wnill coug'alitall<br />
lUll()rlnath)ns illcalkinafihle with
Vol XIX. No. o<br />
- 104 -<br />
Iil'e or tntislkrred into our out of the NICUs<br />
were excluded in>)m the study. Very lew<br />
inLaits Iruom either NICU were translerred<br />
out.)Tlhere were 361 eligible iadniisi¡us to<br />
uits A and I over dithe study peridl ( IY9J (u<br />
unit A ¡id 162 to unit Bi). Of diese. 61<br />
suflered neonatal death and thus became<br />
the study cases, while 150 of the 300<br />
suarvivors were selected fir the eointrol<br />
(relcrenue) group.<br />
The initial results are sunmarized in<br />
Table 1. The crude ratio of the rUtes between<br />
the units, 1.9, was signifiant at t the<br />
0.(. level, faiirdy well ruling out chance<br />
aloune as an explanation of the diflference<br />
(Table I). Thle m¡ethoad uf rte computation<br />
is brietly described in the appendix. Using<br />
both univariate and multivariate statistical<br />
techniques, ' 4 more than 30 risk fatours<br />
were exwrnined as possible contributurs to<br />
die ditierence. These are listed in Table 2.<br />
Few tumed out tu be of any inmportanuce,<br />
mtot Lbecuse of being similarly distributed<br />
between the units. and sume because of<br />
their very weak ctontribution to risk of<br />
death. Ethnicity (race) was distributed<br />
quite differently between the unm and<br />
nearly all of dhe interunit differenee in<br />
death rates was concentriated in the premature<br />
infants (les dthan 1500 grnams birthweight).<br />
After adjusting for race, the rate in<br />
unit A was nmore tdiu three times die rate in<br />
unit B among prematures, and the absolute<br />
rate differences were quite high in this<br />
group (more than 35 p>er ceit). Table 3<br />
sulniaurizes thiese details. Further i nvestigatiln<br />
of the elev::.'ed rutes in unit A will<br />
benetit by this initial elimination ofseveral<br />
ix>ssil)le explanations (such as ethnie diflerences)<br />
aiad will be able to lcus ou. risk<br />
iLwtors and aspects of care that primllrily<br />
alieSt premature inlants.<br />
Olher Conideraiiiau<br />
A majior claas orflrolhletis in cas-cuaultnol<br />
statli
CREENLAND iT AL<br />
- 105 -<br />
TABLE 2. Fiacturs Exuri.iwed i r<br />
ColtlribltiHn tul h ilri teielit<br />
Death Raite Dillcsruic'<br />
Maternmal ae (yeAr1)<br />
Raie/ (Black; Hipanic; other)<br />
Cnavidity<br />
Numli.r of dpl ,umneous abor.ltís (20 weeLk<br />
Prenatal cue (yes; no)<br />
Hydramiios (yes; no)*<br />
Abnoeroll presentation (yes; no)<br />
Cord prolepie (yes; no)<br />
PlMaenta abnormalties (bruptio, previa, etc.)<br />
(yes; no)<br />
Oiyutoin (no; augimetaiuun; ieduciuil)*<br />
Vaginal delivery (no; ueouplica(ed;<br />
complicated-braech, moldfocepa. vacuu¡m, faled<br />
forcepa or vauuim. etc.)<br />
C-sectiou (no; repeat or pnriauy elective;<br />
nonelective)<br />
Abnormal dugnton ofaibor(no; 20 hn<br />
Seu<br />
Birthweight (grais)<br />
Cesattional age (Dubowitz) (weeks)<br />
Apar I iian. (by pediasticui)<br />
ApSar 5 inio. (by pedimcri¢ia)<br />
eauscattion al deolvery tendotra(chei<br />
intubatlon; no)<br />
VMor consenital abormality. ch(uroounie/genetic<br />
defect. etc. (no; yes, potentially viebl)<br />
slteliratory dintrins syndrumaneresiriatory miilure<br />
(uaswtlated with tmmiuunty andlur pernna)<br />
ap.ipyua) ('es; no)<br />
Meuniunm/biluduasnintic fluid spiratioia (ye; no)<br />
Provel iel(e.tiun (no; cougeni il or neonalal. Ro<<br />
horsiital.acluired) (infctiuns frli bo' .e of<br />
nouuuomiial oriyin-e.la. buterial sepuis with<br />
unire >3 dary pu)dielivery-were cuded "no"e<br />
ls;oi uiiiioíiiítiofsi4ther ígyoKeniral hernmlytic<br />
disorder req lirings exlchanl tria slusoiu)(yes; no)<br />
Signifiiclat iirth trautuilitjury s c; no)<br />
iirJtl oof hospital (home. iln raiulit. etc.) (yes; no)<br />
Nuiber ol' da»y in hospital (0-24. hr> . I day)<br />
'l'. ltac, tBiis silflred Irdsn ¥ ib levecls f r eímrdilag<br />
iluacuracy iii dte recirds esauIalUleLd<br />
Discussion<br />
MiDICtAL Ci<br />
Plrolpr applicatio of tlihe cUse.uitrol<br />
approach requires consideratiou of and<br />
concerted efforts tou meet a number of<br />
criteria for study (internal) validity. These<br />
criteria have been extensively discussed<br />
asid systemiiatzed li¡ tihe recent epi-<br />
- "<br />
demiologic literature.. Chief amolg<br />
the criteria have been selection validity<br />
criteria (concerning bias in selection),<br />
inlormation validity criteria (concerning<br />
dite quality of the inilfianatíio on the risk<br />
factora under study) and couiparnson validity<br />
criteria (concemrning the control of confounding).<br />
Efforts should be made to meet<br />
these criteria as far as possible in any area<br />
ofapplication ofthe case-control method. A<br />
researcher considering a case-control appnrach<br />
should carefully evaluate whetlser<br />
his study setting would allow fulfiliment of<br />
the various validity criteria. If selection.<br />
informnation arid comnparison valility<br />
criteria cannot be met. the study will be<br />
unsound. These criteria apply to recordbased<br />
cohort ("historical prospective")<br />
studies as well.<br />
Special caution is required in the use of<br />
routine medical records for case-control<br />
'and historical prospective studies, sinee<br />
biased recording of information on the<br />
study subjects will produce corresponding<br />
biases in tdie study results. Investigatnrs<br />
must be alert to the possibility tthat the use<br />
of a particular treatment regimen led to a<br />
more frequent recording of the outcoimte<br />
under study or thbat the treatement under<br />
study was recorded more freqmaently<br />
mutiong tbose experiencilig the outconle.<br />
These were clearly not possibilities in our<br />
NICU study (where the "treatment" was<br />
the NICU). but such problenms are frequent<br />
in nonexperimental drug evaluations."<br />
Impoortant in any mionexperinientil shady<br />
of mnedical treatments or technology will<br />
be txontrol of l'cnfounding.a Conflmntditlg<br />
warrants special attention in nonexperilmelntal<br />
ttclisuolohgy eva;ltl;itioi lIi.calibt' o<br />
tdie possiility ,l "cbu¡llouldinig by itídli.tioín"i";<br />
this (otic'rs whenever prognostic
1<br />
- 106 -<br />
vol. xix N. 8 CA.E.CONTItOL METHOD<br />
TALLE 3. Finael Comptison vi' Neonatal Intensive Care Units<br />
¥lbior's Estiisntud<br />
iirtlh N>. No. EEILctulcd Eiá. Hice<br />
¡tlm. Weight Unit uses Controlss ea~lh ise* Test Iaio<br />
stlck Under<br />
1500<br />
Crmanm<br />
A<br />
B<br />
16<br />
2<br />
8<br />
7<br />
50^.L<br />
12.5<br />
p < 0.05 4.0<br />
ai"ck t)Over<br />
150t)<br />
Grams<br />
A<br />
is<br />
4<br />
2<br />
31<br />
8<br />
6.1<br />
11.1<br />
NS 0.5<br />
Oiheri Under<br />
1500<br />
CGiunw<br />
A t<br />
5 S<br />
2<br />
U<br />
73.3<br />
1.7<br />
p < .02 3.4<br />
Odbrl Over<br />
1500O<br />
Crun~<br />
A<br />
1<br />
12<br />
9<br />
37<br />
48<br />
14.0<br />
8.6<br />
NS 1.<br />
* Comrputed using Blyes' Lhcurm (ee appendu).<br />
t Prinuaily tisplpaic.<br />
NS - n signifirúant 0.05 level.<br />
fators for the outcome under study served<br />
as indications or contraindicatf, s for the<br />
application of tie treatmnent under study.<br />
Analytic control of confounding will require<br />
that accurate information be available<br />
for all subjects on important potential<br />
confounders (e.g., in the NICU study. it<br />
was necessary tou have accurate iniornation<br />
on ethnicity, birthweight and other determinants<br />
of neonahill mortality).<br />
Control of coniounding can only be<br />
evaluated re!jtive to subject-matter<br />
knowledge and judgment regarding die<br />
study sitauation. Even when "hidden" (uncontrolled)<br />
confounding is believed to<br />
exist in the study results, however, the resuilts<br />
may still provide useful information.<br />
For example., in our NICU study, it is still<br />
possible that same unrecorded risk factors<br />
(perhaps with dillkrential implications for<br />
admiission to units A and B) rather than<br />
GREENLAND ET AL.<br />
3. Cornfleld J, Haenszel WH. Some aspects of retrospective<br />
studies. J Chron Dis 1960;11:523.<br />
4. Mantel N, Haenszel WH. Statistical aspects of<br />
the analysis of data from retrospective studies of disease.<br />
Natl Cancer lnst Monogr 1959;22:719.<br />
5. Neutra RR, Drolette ME. Estimating exposurespecific<br />
rates from case-control studies using Bayes'<br />
theorem. Am J Epidemiol 1978;108:214.<br />
6. Prentice RL, Pyke R. Logistie disease incidence<br />
models and case-control studies. Biometrika<br />
1979;66:403.<br />
7. Schlesselman JJ. Samnle size requirements in<br />
cohort and case-control studies of disease. Am J<br />
Epidemiol 1974;99:381.<br />
8. Dom HF. Some problems arising in prospective<br />
and retrospecti ve studies of the etiology of disease. N<br />
Engl J Med 1959;261:571.<br />
Appendix<br />
MEDIcL CARE<br />
9. Kleinbaum DG, Morgenstern H, Kupper LL.<br />
Selection bias in epidemiologic studies. Am J<br />
Epidemiol (in preas).<br />
10. Sackett DL. Bias in analytic research. J Chron<br />
Dis 1979;32:51.<br />
11. Cole P. The evolving case-control study. J<br />
Chron Dis 1979;32:15.<br />
12. Feinstein AR. Clinical biostatistics. St. Louis:<br />
Mosby, 1977.<br />
13. Greenland S, Neutra RR. Control of confound.<br />
ing in technology assessment. Int J Epidemiol (in<br />
press).<br />
14. Miettinen OS. Efficacy of therapeutic<br />
practice-will epidemiology provide the answers?<br />
In: Melmon KL, ed. Drug therapeutics. Elsevier:<br />
New York, 1980.<br />
The rates given in Tables 1 and 2 were computed from the casecontrol<br />
data using Bayes' theorem. A detailed and general discussion of<br />
this method is given in reference 5. Briefly, suppose we know the<br />
overall rate of the outcome, P(D), the probability of exposure among<br />
cases, P(E/D), and the probability of exposure among noncases, P(E I<br />
D). Letting P(D) = 1 - P(D), Bayes' theorem states that the outcome<br />
rate among exposed persons, P(D/E), is given by<br />
P(D 1 E) = P(E I D)P(D)<br />
P(E 1 D)P(D) + P(E D)PD)<br />
In our NICU study, the total size of the target population (unit A + unit<br />
B) was equal to the number of cases (61) plus twice the number of<br />
controls (2 x 150)or 361; the ital number ofcases over the study period<br />
was 61; and so P(D) = 61/361 = 0.169 and P(OD) = 0.831. To illustrate<br />
Bayes' theorem, consider computation of the rate in the first row of<br />
Table 1. Here the exposure is "unit A," P(E 1 D) = 43/61 = 0.705, and<br />
P(E [D) is estimated as 78/150 = 0.520. Thus, using Bayes' theorem<br />
P(D 1 E), the rate in unit A, is estimated as<br />
or 21.6 per cent.<br />
- 107 -<br />
P(D | E) = 0.705(0.169) = .216<br />
0.705 (0.169) + 0.520 (0.831)
.oó'io..o. M..:an. V1it. Vol, 0, PP. {5g-lb6. lerogsrlm Pies., 1976. Printed in GfetI Bilnain<br />
PATIENT _LOW ANALYSIS AND THE<br />
l)FlIVFI,¡Y <strong>OF</strong> RADIOLOGY SERVICEt<br />
BENJAMI N L¿E;, GEORGE REVESZ§, FRANCIS SHEA§<br />
aind ROBERT CALTAGIRONE§<br />
Temíple Universily, Plhiladelphia, PA 19122, U.S.A.<br />
(Received 5 February 1976)<br />
- 108 -<br />
Abstract-in recent years there has been an increased awareness regarding the cost of radiologic health care, and the<br />
patient delays encountered in the delivery to the consumer. The purpose of this paper is to demonstrate that, at least<br />
in one case in the Diagnostic Radiology Departinent al Temple University, the assumplion that better service can be<br />
given to patients provided more technicians and orderlies are available, is not valid. The facts tend to indicate that the<br />
real problem lies in scheduling techniques, and improved utilizalion of available equipment. Therefore, it is safle to<br />
conclude that for improved radiologic services, the emphasis should be directed iowards the design of the management<br />
systems and scheduling techniques, and not the staff andior facilities.<br />
INTRKOU;C'LION<br />
At a time, when there is a continued increase in demand<br />
for health care service,it is assumed that a reason for<br />
inclfrclivc scrvie lo pafients is the shortage of manpower<br />
and facilities. An analysis of Ihe I)i>gnostic Radiology<br />
Department (DRD) at Temple University Hospitai was<br />
organized, searching for reasons associated with the long<br />
waiting times of patients in the DRD and the low<br />
utilization of ecuipment. It has been previously assumed<br />
that betrer service could be presented to the consumers if<br />
more technicians, orderlies and examination rooms were<br />
available at the hospital. However, such a move would<br />
have a tendency to increase the costs of radiologic<br />
services al a time when costs are increasing at an alarming<br />
rate. In many instances, managers suspect reasons for<br />
their inefficient systems performance, but it is only after<br />
an in-depth study is made that the basic causes of the<br />
inefficiency are evident. Moreover, the suspected reasons<br />
appear to be of secondary importance.<br />
In this particular case, the long periods of patient<br />
waiting time cannot be decreased by adding more<br />
technicians or orderlies as some had surmised, but that<br />
patient waiting time can be reduced by improving<br />
scheduling techniques. Better management methods; such<br />
as more sophisticated scheduling algorithms, automated<br />
systems and computer control can be utilized with the<br />
present staff and equipment. The effects will contribute to<br />
decreased patient waiting time, and the total time spent in<br />
the DRD. At the same time, patient service capacity<br />
shouid be increased in the DRD with the present number<br />
of rooms, technicians, orderlies and staff. This increased<br />
cpacity will then enable administrators to accommodate<br />
the expected increase in demand for radiographic services<br />
as predicted in Knowles II, Morgan[2] and National<br />
Advisory Committee on Radiation[3].<br />
Recently, there have been several reports alluding to a<br />
potential shortage of radiologists in thc United States in<br />
the near future. This potenlial shortage is predicted since<br />
the demand for radiologistís' time is increasing al a more<br />
tl'his work w;s supportedl in p;rit hy (¡;tl;' ;M 1454S8-0(.<br />
National Institute of General Medical Scienet,, United States<br />
Public Health Service. All correspondence shoul) be direcled lo<br />
the first author.<br />
tSchool of Business Administration.<br />
§Department of Diagnostic Radiology.<br />
1Table I lists and explains all symbols.<br />
rapid rale than is the supply of radiulogists. Any new<br />
national health insurance program, if enacted, would<br />
presumably cause an even greater inbalance between the<br />
demand for radiological services, and the supply of<br />
radiologisis.<br />
Improvements in DRD can be categorized in three<br />
areas. The first is increased utilization in personnel and<br />
facilities which has been reported by Lindhein[4] and<br />
Revesz et a1.(5,6]. The second area is improvements<br />
attempted by simulation technique. See studies by Covert<br />
et al.[7], Jean et al.[8], Kenny and Murrayl9] and<br />
Lodwick[10]. The third area emphasizing Computer<br />
Scheduling and Control is reported in Donald and<br />
Waxman[Ill, Hansen and Sniderll[2 or Hsish(13].<br />
Computerization of manual methods has demonstrated<br />
that scheduling can also be applied to large departments.<br />
To date, however, no mention has been made of an on-line<br />
scheduling system, which can be dynamically updated as<br />
the patients are processed. In addition, limited research<br />
has been conducted concerning the development of<br />
scheduling rules which have general applicability.<br />
In view of the many possible policies that can be<br />
considered for improving the delivery of radiologic care,<br />
it is necessary to present the data quantitatively for<br />
analytical purposes. Consequently, this paper will investigate<br />
some of the effects of these policies on the DRD. In<br />
most instances DRDs at hospitals are confronted with<br />
similar problems. The methods of providing radiological<br />
services is apparently identical at all departments. The<br />
patient arrives at the department and immediately enters a<br />
sequence of service facilities, which culminates with an<br />
X-ray examination. It should be recognized, however, that<br />
departments may differ in the number of examination<br />
rooms, the procedure used andother non-major facilities. In<br />
most DRDs, however, the patient flow is basically the same.<br />
It appears to be more logical and convincing to analyze the<br />
DRD at Temple University Hospital, using its specific data<br />
and not discuss a hypothetical DRD. Moreover, the<br />
generalized model developed in this study is of sufficient<br />
generality to be associated with the DRDs in most hospitals<br />
with no more than minor modifications.<br />
SYSTEM DESCRIP'lION<br />
The system under study is the Temple University DRD<br />
which has an annual volume of 72,000 X-ray examinations.<br />
The service is provided both for inpatients (IP) and<br />
outpatients (OP), and the ratio of IP/OP is 55145. Figure
160<br />
I indicates the flow of patients through the department.<br />
Many of the patients are scheduled. Experience<br />
has shown that the scheduled paticrts will either arrive<br />
and enter the department too early, or will arrive too late.<br />
Scheduled inpalients are assisted by orderlies to arrive at<br />
I)RD in 20 min, depending on lile ivailability of clevators.<br />
Due to these random elements, it is assumcd l:al the<br />
patients enter the DRD with an interarrival distribution<br />
time of f(t); with probability P, of being an outpatient,<br />
and wilh prohahility I - P, of hcing an inpatient. The<br />
inpatients will wait for ocie of I¡le ¡enl orderlies (Ot : 1(1)<br />
for assistance to be taken to the control desk by one of<br />
three means of transportation; walking, wheelchair and<br />
stretcher with probabilities P2, P 1, P,, respectively. An<br />
oulpalient reporis to thc reception Jcsk itt which inme the<br />
individual is serviced for time r,. A fraction P5 of the<br />
outpatients will change to a hospital gown which takes time<br />
r2 if one of the dressing rooms (DR = 16) is ava!lNble. The<br />
outputient then reports lo the control desk and sNpends time<br />
,t. Each patient using thc dressing rooms will lock ¡he<br />
room for the entire period of the examination and therefore<br />
prevent others from utilizing the room until the individual<br />
is released.<br />
At a typical DRD, Ihere are over 200 different types of<br />
examinations which can be grouped into 13 major<br />
categories with minor variations within a category.<br />
For the most part, however, the demand for the<br />
different radiographic examination will vary over the day.<br />
Gl. BE and IVPt are performed during the morning hours<br />
before the patient has eaten; while a Myelogram is usually<br />
scheduled for the afternoon.<br />
Table 2 presents a list of the 13 examinations with the<br />
corresponding mean examination time 74, and the range<br />
for cach category. Pi(j) is the probability of having<br />
examination type j at period i = (8-10 a.m.), i=2<br />
(10 a.m.-12 p.m.), i = 3 (12-2 p.m.), i =4 (2-4.30 p.m.).<br />
The patient is then assigned an Examination Room<br />
(ER= 14), at the control desk. This assignment is an<br />
important one since it determines the length of stay for<br />
that patient in the queue. The DRD at Temple is one<br />
where not all examination rooms are equipped with the<br />
tExp'anations of category names are given in Table 2.<br />
R u. IrV orr<br />
,, nl<br />
Table 1. List and explanation of variables<br />
inpalient, l Ool...n.I<br />
.- 109 -<br />
1d,--. v 1 C-l'eI - ( ,*<br />
Th Wpellntait lo o r n po Dcesng it r<br />
Fi1. nrow. Maeporflol owharl tpatien<br />
Tjma<br />
sam facilities, and oy cenain rooms can prformrly<br />
specific examinations. Most of the examinations require<br />
one of the Technicians (TE= 10), while other rooms<br />
require radiologists. When the examination is completed.<br />
the patient waits time as for film processing with the<br />
probability P6 that the individual may need additional<br />
films to complete the study. If supplementary films are<br />
necessary, the patient then returns ¡o the control desk<br />
with high priority. If the study is adequate, the outpatient<br />
is released, and the inpatient will wait for an orderly to be<br />
returned ¡o the room which takes time Te.<br />
EVALiJAiON <strong>OF</strong> SUCH A SYSTEM<br />
It is important to recognize that in most large systems,<br />
there is mnore than one measure of performance. Thus, it is<br />
not surprising that in this case there are several, some<br />
Vt..' i.lMl, ' -xp i .na11It'on DI i lelstill ¡nll<br />
f (t)<br />
Inter Arrival Time letween Two Patienta<br />
rl Service Time At Reception Desk<br />
,t 2 . eDressing Time<br />
r3 Servicr Time At Control Desk<br />
T'1 Examination Time<br />
y5 Iíilm Process Timne<br />
(Walk<br />
T1 t ~Trau.,lorlotion<br />
Time To or rroma ~ ielechair<br />
1'.- IhgUinrlmelll r<br />
iStretcl.lr<br />
P1'<br />
k' S<br />
I''rceintoge Of Outpatients<br />
Ierentage Of Walk/ Wichelehair/ Stretcher<br />
l'ercentage Or Outputients Needing Dressing Room<br />
p; PGl'.ce'tag Of' I etrlntu N ti.dilg Adlitinoial tilm<br />
ER í ,,I:xtnll Jtoll NoOmS<br />
OR Orderlier<br />
TE Technicians<br />
DR Dressing Rooms<br />
Un 1 unm<br />
Uniform<br />
Uniform<br />
Constant (t1 lin.)<br />
See TabLc 2<br />
Constant (10 Hill.)<br />
Unfarorn<br />
Uniform<br />
Uli fornm<br />
45X (55% lnpatlent)<br />
5/20/7W%<br />
803<br />
llI<br />
10<br />
16
latient iow analysis and the delivery of radiology service 161 -110-<br />
Table 2. Data concerning various examinations: probability of having the examination (as function of time in the day).<br />
times(mean.range).roomequipped toperform theexaminations(before í I a.m. and afier 1 a.m.)<br />
, 1 2 3 4 S 6 7 8 9 10 LI 1: 1)<br />
NlAl.' f El.,,Il;il.ll... "<br />
SLik,. SIi'1.i" Cl..t .. n Ny..lo Abd. GI BE IvP tojo Fluor., PEt; :II<br />
Pi (J) 8-10 A.M. 0 0 32 0 0 0 20 20 20 0 0 0 u<br />
f 2 (J) 10-12 A.M. 13 17 42 20 0 0 0 0 0 2 2 2<br />
P 3 1 () 12-2 P.H. 13 17 42 20 4 0 0 0 0 1 1 I<br />
r'. (J> ¿-:30 P.M., U1 I 8l 20 0 12 0 0 0 0 0 U 0<br />
"an Exao. Time (HIn.) 12 t16 6 10 60 10 100 45 60 40 20 YU i5<br />
Rane Ex~.. TI~ (
162<br />
CONGESTION POINTS ANU CONTROL.ABLE<br />
VARIL'.LES<br />
It should be recognized however, that such a complex<br />
system has several congestion points. Specifically, some<br />
of the more important ones are:<br />
Q, In front of the reception desk;<br />
Q2 In front of the dressing room;<br />
Q, Inpatients waiting for an orderly to be assisted to<br />
the department;<br />
Q4 In front of the control dcsk:<br />
Q, In front of each examination room;<br />
Q" Inpatients waiting for an orderly to be returned lo<br />
the room.<br />
In addition to the queues, there is the problem of<br />
technician flow and orderly flow. In many instances.<br />
Iechnician and orderly flows are delayed because of the<br />
congestions in the system which are beyond their personal<br />
control.<br />
Before evaluating the behavior of the system as results<br />
from changes in the input, it is necessary lo determine<br />
what parameters can be changed. The capacity of the<br />
facility is greater than the volume of patients and,<br />
therefore, it does not seem reasonable to reject patíents.<br />
Thcrc is a limil to Ihe numbor of patients in somc<br />
caUegories, but, in general, more patients can be seen than<br />
at the present level. The scheduling procedure determines<br />
the time of arrivals but the number of patients is under<br />
limited control.<br />
There is some control regarding the patient's arrival<br />
time, but in many cases this situation is limited. As noted<br />
previously, some of the examinations may require an<br />
empty stomach, and therefore must be completed early in<br />
the moming. Another problematic area is that patients will<br />
arrive two hours before or after the scheduled time, and<br />
must be accepted for treatment. In other words, there is<br />
some control on the arrival but it is often limited by<br />
extraneous circumstances.<br />
Certainly, the parameters of the system can be<br />
changed; i.e. number of technicians, the number o'<br />
orderlies and the increase rate of service at the reception<br />
desk. But most important, the decision that is made at the<br />
control desk regarding the room assignment appears to be<br />
one of the key factors for the efficiency of such systems.<br />
In this sense, one way to improve the performance of the<br />
system would be through changes in the room assignmenlt<br />
decision. This decision is not easy since it must take into<br />
consideration the rooms that have the :uipment to<br />
perform Ihe examination, as well as the lines in front of<br />
each room. At present, this decision is performed by a<br />
clerk. An example of the decision tree for the room<br />
assignment of a patient requiring a chest examination is<br />
presented in Fig. 2. It should also be pointed out that<br />
Rooms 4 and 7 are available for chest X-rays before<br />
II a.m., and Room 4 does not have the equipment to<br />
handle stretcher cases. Decision trees for other examinations<br />
are even more complicated when requiring multiple<br />
phasc examinations, and more than one room as for cases<br />
concerning upper gastrointestinal studies (GI), and barium<br />
enemas (BE). Table 2 clearly indicates the rooms that can<br />
perform the various examinations before 11 a.m. an " -<br />
II a.m. (before 11 a.m. some of the rooms are used tor<br />
special studies).<br />
MTHOWDOLOGY<br />
The department described above is a large and complex<br />
facility. The behavior of one part of the system is<br />
dependent on the output of another. Therefore, the<br />
B. LEY et al.<br />
Fig. 2. Chcsl palient lecision trec for nrim assignment.<br />
- 111 -<br />
arrivais to one service station represents the departures<br />
from another service station. Consequently, variables are<br />
interrelated and there are numerous system parameters.<br />
Since the matter is complex, it will be impossible to<br />
analytically optimize the operation of the department, and<br />
to develop compact results in closed forms. Therefore, a<br />
decision was made to utilize simulation techniques which<br />
have been proven useful in similar applications. A<br />
simulation program was then written for the patient flow<br />
in DRD. More specifically, GPSS (General Purpose<br />
Simulation System V) is combined with Fortrar IV, and<br />
the program has been implemented on an IBM 0/165.<br />
For each experiment, the following sample siz, vas<br />
taken. Four vectors were generated: P(i) = (P,, P, ....<br />
":.; = 1, 2, 3, 4. All four vectors have a similar patient<br />
mix ¡( -me percentage of the 13 categories). For each<br />
one of t. - %k tors P(i), 10 repetitions were simulated<br />
with rando,,,._í. '-r the stochastic variables. In certain<br />
cases, a larger nu,. ' r of runs were performed in order to<br />
test convergence. T' - randomness was in the service<br />
time, method of patí..i, transportatinn (walking, wheelchair,<br />
stretcher) and oth,. ctochast's i,.ameters. Thus,<br />
cach experiment included 4 uu, x 160 aticnll/day x 10<br />
repetitions, which resulted in 6400 patients. To observe<br />
changes over vanrious number of technicians, ;..y 4, 6, 8,<br />
10, the sample size was 4 x 6400 = 25,600 patients.<br />
VAUDATION<br />
One of the important phases of any simulation is to<br />
verify its performance as to whether or not it replicates<br />
the actual system. In order to satisfy the requirements of<br />
thc study, statistical information w:as derivcd from DRD<br />
over a two year period, includin? Jata on performance,<br />
and corpp.-zd with the results from the simulation model.<br />
The results which include a X 2 test for goodness of fit at a<br />
level of significance, a = 0.05, c' ,níy indicates a good<br />
agreement between -tu; jRD and the simulation<br />
model. The res" ,.resented in Table 3.<br />
Tests wer .,ipleted in the simulation model to<br />
measure t' ..rtormances; under a typical daytime load<br />
of 1i · .ents, under a heavy load of patients (220<br />
pat:. ..s) and under a light load of patients (135 patients).
¥aticnt flow analysis and the delivery of radiology service 163 112 -<br />
Tablc 3. Comparisonbetweensimulationandactual syslem<br />
135 P a i e n ts ay b60 P a t i e t s I a y<br />
waiting Time Before StuJy (Min) 'leasured Sinmulation X2(x2) *<br />
(easuread Simulation , ( ')<br />
Al Done,<br />
NI ,:e 1 1 uncou,<br />
All. Patients<br />
Toitl 1imr in lepartnrnlt (Flii)<br />
Al I lli, ..<br />
Mlajor Fluoros<br />
tliscellaneous<br />
All Patients<br />
Techltni.í:w Utslizationl ;<br />
Orderly Utiltzatilo :<br />
Room Utili:ation :<br />
1 7 (31)<br />
1 2 (58)<br />
r,~ (.'n<br />
i1 (1 ,1<br />
,' ((35)<br />
.1 I .1.1<br />
102 (i5)<br />
63 (155)<br />
3.><br />
42<br />
5!<br />
IB (35)<br />
Iih (G2)<br />
.It (2.11<br />
1i (II,)<br />
23 ( 35)<br />
.1<br />
(i.s)<br />
(,7<br />
(l' IS<br />
90<br />
70 (( 35)<br />
31-31 ranlgL<br />
I-433 rangc<br />
34-41 range<br />
\otc : 135 ,liatencs. * H II deiliciai*. 10 orderlics. 12 cxaJinJtiOfl rooms<br />
li(o patiOlVcts. IO 10 %cdalll, llai 10 o;'dei.l.s. . I14 ;unttiittio i l roums<br />
6. 78 (.93)<br />
7.t (.9JU)<br />
( · ) nae numbers in parentlhce.se aro the number of patients that lthe times are based upon<br />
21<br />
21<br />
25<br />
(bl )<br />
(69)<br />
(18)<br />
1 (¡16)<br />
58 (61)<br />
121 ( 1)<br />
81 (18)<br />
69 (166)<br />
The measured data and thle simulated data are froa the same population at the leyel of a * .05<br />
The results disclosed that the model behaved as expected.<br />
(See Shea el ul. t14].) Having ascertained the aceuracy of<br />
the model with respect to the real life situation, sensitivity<br />
analysis would then be pcrformed with respect to the<br />
parameters, and the measure of performances at various<br />
conditions. The cxperiments concerning the simulation<br />
can be described as follows.<br />
A. The effect of changing the number of technicians<br />
Presently, there are 10 technicians in the core<br />
department consisting of 14 rooms. Several "runs" were<br />
made with the simulation model, varying the number of<br />
technicians from 4 to 10. As anticipated, the system is<br />
overloaded with 4 technicians, and the waiting times and<br />
total times are very high-50 min and 110 min-as seen in<br />
Fig. 3. When the number of technicians increases, the<br />
measure decreases but only to a certain level when the<br />
times reach a threshold. One implication is then clear;<br />
waiting time and total time cannot be decreased below a<br />
.1-<br />
E<br />
S.<br />
.r4<br />
1oo0<br />
ots<br />
60<br />
40<br />
20<br />
'I<br />
%x<br />
:<br />
4 6 a<br />
-<br />
19<br />
Number ot tectinicians<br />
Orderly util.<br />
Total time<br />
\ Technicion util.<br />
--Room u(til.<br />
' Dressing rm. ulil.<br />
Waiting time<br />
No. potients ct<br />
4:30p.m.<br />
Fig. 3. 'Me effect of changing the number of techiricianís.<br />
So<br />
54<br />
38<br />
17 (40)<br />
16 (70)<br />
20 (.J(<br />
1: (1:tl<br />
t*J (ctX)<br />
50 ( l(><br />
87 (20)<br />
65 (t60)<br />
51-55 range<br />
50-7L rangii<br />
$g-44 range<br />
2.01 (.. 35)<br />
certain leve¡ by adding more techíticians. This fact can be<br />
explained by nu>ting thart the problem is nol with (he<br />
technicians, buz with a combination of the number of<br />
orderlies, rooms and ¡he scheduling procedure. The DRD<br />
operates efficiently with 8 technicians, but an additional<br />
technician is necessary for absenteeism.<br />
Similarly, the: number of patíenis in the: department al<br />
4:30 p.m. decreases, with the number of technicians, but<br />
the residual number stabilizes with 8 teáhnicians, and<br />
does not decrease further with additional technicians.<br />
Technician utílization decreases as the number of<br />
technicians increases due lo the faelt that the amount of<br />
work for afi technicians remains constant. Therefore,<br />
increasing the number of teclínicians results in a lower<br />
utilization for cach technician.<br />
The utilization of other service stations is stabilized and<br />
constant when the number of technicians rises above (I.<br />
Orderly utilization is about 0.70, recoption desk utifization<br />
is about 0.55, room utilization 0,43, and control desk<br />
utilization is, about 0.30. lt is important lo point out that<br />
none is affected by the change in the number of<br />
technicians.<br />
B. The effect of changing the number oj orderfies<br />
The next pararneter lo be varied is the number of<br />
orderlies in the system. At present, there are 10 orderties<br />
and Fig. 4 demonstrates the effect of changing the numbor<br />
of orderfies from 6 lo 12. Figure 4 clearly ¡radicales that<br />
the number of orderlies has ¡¡ttle affect on the plotted<br />
measures of performance. The most aflected is the<br />
utilízation of orderlies which decreases as the number of<br />
orderlies increases sínce the same amount of work is<br />
shared among more orderlies. lt also has an effect on the<br />
number of patients in the department at 4:30 p.m. This<br />
number decreases from about 25 for 6 ordlerties lo 10<br />
patients for 10 orderlies. Other than the two changes, the<br />
measures of performance are almost unaff ected and reach<br />
some constant value for 8 or more orderties.<br />
C. The effect of decreasing the nuniber of examnination<br />
rooms<br />
The succeeding experiment involves the possibility of<br />
reducing the number of examinatíon rooms from 14 at the<br />
present time to, 12 rooms. Table 4 ¡radicales the changes in
164<br />
c 8o<br />
Table 4. The cffect of chaing the number of examination rooms (at 135 patients/day, 10 technicians. 10 orderlies)<br />
Toltl Tiwe<br />
,l the S¥ysttr *(' 1 patients)<br />
h'a ting TiJmne<br />
( J.,pal jont I)<br />
(Ohtpnttents)<br />
i;. Ils. ,%y l.l.. JAl 1 . :.<br />
(Inp.ati:nts)<br />
(Outpatientc)<br />
Nwu.bLr or P'atient at t 4:30<br />
Teclmbilc:n Utiti.xaioii<br />
Ordlerly<br />
12 KRar 11i Room. (AL I-rvs.irt)<br />
79 Mi,,utes 58 Mlinutes<br />
99<br />
F,4<br />
17<br />
lO<br />
9<br />
.110<br />
·3lO<br />
I)rl.-Ksl- g Ro ' .58 .31<br />
60. - Totcl time<br />
ci Orderly util.<br />
40 - -0- - . Room util.<br />
20<br />
20 '________ __ _" _ " _-. W oitingtlm e<br />
No. ptients at<br />
4:30pm<br />
6 8 10 12<br />
Number of orderlies<br />
Fig. 4. Thc ellecl of changing the number of orderlics.<br />
the performance parameters and illustrates that total<br />
times and waiting times are going to increase significantly.<br />
As a consequence, total time for outpatients increases<br />
from 69 to 99 min, and waiting time increases for all<br />
patients from 12 to 28 min; for inpatients it increases from<br />
8 to 17 min, and for outpatients from 20 to 40 min. Thus, it<br />
is safe to generalize that system performance is obviously<br />
affected to varying degrees depending on which rooms are<br />
closed and this factor is now being investigated. The<br />
addition of examination rooms was not considered as a<br />
measure to decrease waiting time becausc of thc hb;ih cosi<br />
of each examination room ($100,000-$200,00,,. h<br />
surplus existing in the departments' capacity to handie<br />
more patients, the hospital administrators will not invest<br />
vast sums to decrease patient waiting time and total time.<br />
D. Changing the scheduling method<br />
An experiment was designed to observe the system<br />
performance for a change in scheduling methods. Se:v..<br />
different scheduling procedures were considered:<br />
1. PS-Present Scheduling. At present, the room<br />
B. Lev et al. - 113 -<br />
.31<br />
1Z<br />
20<br />
.61<br />
.37<br />
assignment is based on the smallest number of patients in<br />
front of each examination room, regardless of the amount<br />
of work each patient requires. Once a patient is assigned<br />
to a room, the individual will not be changed to another<br />
room and no switching is permitted.<br />
2. MWL-Minimal Work Load. This scheduling procedure<br />
assigns the patient to the examination room<br />
according to the minimal work load in front of each<br />
examination room. The work load is defined as the total<br />
expected time that the patient will use the examination<br />
room, including the one in process.<br />
3. MMWL-Modified Minimal Work Load. This process<br />
is a modification of MWL which considers the time a<br />
patient enters an examination room and t: ime a<br />
decision of the present room assignment is i,. le. It is<br />
evident that this concept is more accurate and beu,,r than<br />
MWL. In this technique, an examination room is assigned<br />
*.- 4 on the smallest load in front of each examination<br />
roo-.., - .. ibtracting the process time that the patient has<br />
alreads .. - in the room.<br />
4. CQ-Cc- m' Queue. This algorithm' assigns the<br />
patients in one &,u.e queue. As one of the examination<br />
rooms is availabi -e first patient in the common queue<br />
from those who can ta- e the exami.i` ns in that room, is<br />
assigned to the room.<br />
5. MCQ-Modified Common Queue. This process is a<br />
modification of CQ. While in CQ, the natients were<br />
ordered according to the time available to lake the<br />
examination, MCQ orders the patients according to the<br />
arrival time at the radiology department.<br />
6. SPT-Shortest Process Time. As pointed out earlier,<br />
the decision by which patients enter the assigned room in<br />
PS is "First Come, First Served". In SPT, the decision is<br />
made according to the shortest examination of all patients<br />
waiting for this particular examination room. Consequently,<br />
patients with short oxamination times have<br />
priority over thosc with long examinalion times.<br />
7. TSPT-Truncated SPT. T'' -i is a mudification of<br />
SPT scheduling by acsignir - ' on priority to patients who<br />
have been waP:: .Éer beyond a certain time. The<br />
disadvantar ,..' i is that patients with long examination<br />
tim :., get low priority and stay in the system for<br />
a lonp .0e. Truncation was done lo guarantee that<br />
onr , patient waited over a certain amount of time, the<br />
.nuividual would enter the room regardless of the length<br />
of the examination time.<br />
Four different simulation days were performed consist-
ing of the same patient mix and arrival times. Each day<br />
was repeated 10 times for random service time, with the<br />
same expectations concening random personnel characteristics<br />
(dressing time, transportation time, etc.). Thus,<br />
for cach one of the seven scheduling procedures, there<br />
were:<br />
4 days x 160 dPai'y x 10 repetitions = 6400 patients.<br />
day<br />
Table 5 summarizes the data in relation to this experiment.<br />
It is clear to see that MMWL is superior for all<br />
measures of performance with the exception of two cases.<br />
One case is where the number of patients in the system at<br />
4:30p.m. is 15, while the best (MWL) is 14. The second<br />
case is when the total time for which 95% of patients<br />
complete their service is accomplished in 165 min, while<br />
the best (PS) is 163 min.<br />
Therc is a significant differcncc between CQ, MCQ and<br />
the uther five scheduling methods. In all five procedures,<br />
the examinalion room is assigned to the patient at the time<br />
the person leaves the control desk. The patient moves<br />
physically, and waits at the front of the examination<br />
room. Howcvcr, in rega.rd lo CQ and MCQ, this is not thc<br />
case. The patient has to wait in a common waiting room<br />
until an examination room becomes available. At that<br />
time, the technician returns to the control desk and<br />
determines which patient is next in line and can be<br />
examined in this room. The technician has to identify the<br />
patient and direct the individual to the examination room.<br />
In some instances, the distance may be as great as 50<br />
yards, and the patient may be on a stretcher. It is then safe<br />
to assume that extra activities may take about 5 min which<br />
was incorporated into the model. This fact may explain<br />
the reason that CQ and MCQ did not perform as weil as<br />
theoretical results previously indicated. Once again, this<br />
study demonstrates the possible conflict between queueing<br />
theory and scheduling theory. In scheduling theory,<br />
there is more control on the patients (jobs) in terms of the<br />
arrivais, and service times. In queueing theory, as in the<br />
department described above, there is more randomness.<br />
Waiting time before study<br />
OP<br />
IP<br />
Both<br />
Total time in thce system<br />
OP<br />
IP<br />
Both<br />
No. of patients in system<br />
at 4:30<br />
No. of patients waiting<br />
over 60 min for scrvice<br />
Patient flow analysis and the delivery of radiology service<br />
SPT and TSPT were clearly the most unsuccessful<br />
techniques among the seven procedures. SPT in theory<br />
should produce the best mean waiting time, however, this<br />
result tends to diminish as the flexibility of machine<br />
(rooms) selection increases (see Waysont15]). This<br />
appcars to be the case in the radiology department where<br />
examinations can be performed in several different<br />
examination rooms.<br />
When evaluating the various procedures, attention has<br />
to be given to the feasibility and to the cost of<br />
implementation. The CQ and MCQ procedures can be<br />
implemented manually but would require a considerable<br />
amount of bookkeeping, and a means of scanning the<br />
entire queue to determine which types of examinations<br />
are waiting. In addition, the SPT and TSPT procedures<br />
could also be implemented manually. However, it is<br />
anticipated that certain difficulties would arise in attempting<br />
to implement TSPT manually. Moreover, the MWL<br />
and MMWL procedures will require a computer to<br />
constantly update the expected luad.<br />
SUMMARY AND CONCLUSION<br />
This culmination of observations had desirable results<br />
and a model of the DRD has been developed. The model<br />
has been tested and verified for replication of the<br />
performance of the department at a satisfactory level of<br />
accuracy. In addition, any changes in the department are<br />
tested and verified first on the simulation model.<br />
The model used for the study indicates that increasing<br />
the number of technicians or orderlies will not decrease<br />
patient waiting times, and total time in the department.<br />
Increasing examination rooms, which may be promising,<br />
was considered and rejected because of high costs. It<br />
should be pointed out that decreasing the number of<br />
examination rooms is costly in terms of higher waiting time<br />
and total time. A recommendation was then made that<br />
there is no need for additional technician and orderly staff<br />
to improve service, and that a reduction of the number of<br />
technicians by one will not affect the department's<br />
performance. This is based on the fact that there is no<br />
Table 5. Comparison of 7 scheduling procedures for various measures of performances<br />
Waiting time within which 95% of<br />
palienis reccive scrvice<br />
Total time within which 95% of<br />
patients left the system<br />
'Best value.<br />
'Off by I patient.<br />
'Off by 2 min.<br />
PS MWL MMWL CQ MCO SPT TPST<br />
33<br />
18<br />
23<br />
79<br />
62<br />
68<br />
28<br />
12*<br />
18<br />
75<br />
57<br />
64<br />
26<br />
12'<br />
17*<br />
72*<br />
56'<br />
62'<br />
32<br />
19<br />
23<br />
78<br />
67<br />
71<br />
30<br />
19<br />
23<br />
77<br />
65<br />
69<br />
35<br />
19<br />
24<br />
81<br />
63<br />
70<br />
31<br />
19<br />
29<br />
77<br />
66<br />
70<br />
20 14* 15' 18 18 18 18<br />
16 12 II1' 25 22 20 20<br />
69 64 62* ' 99 93 101 88<br />
163' 172 1652 177 174 188 183<br />
165 -14 -
166 B. LEV etal.<br />
significant difference between the performance when there<br />
are 9or 10 technicians and 10 orderlies (see Fips. 3 and 4).<br />
As a result of the study, a decision was thn issued to<br />
change the scheduling procedure to MMWL. In order to<br />
implement (he procedure, a PDP-II Mini-Computer was<br />
purchased and the operation of the DRD is now<br />
computerized. In particular, the room assignments which<br />
were performed manually are now completed by MMWL,<br />
taking into consideration the anticipated load on the<br />
rooms, and updatcd feedback from the rooms conccrning<br />
the amount of remaining work. This is accomplished by<br />
the technicians who report to the control desk aftter<br />
completing the last patient, and the control desk then<br />
notifies the technician of the next patient. However, it is<br />
too early to report on the efficiency of this dynamic<br />
on-line scheduling system. Moreover, the staff is currently<br />
involved in the phase of adding options and functions. In<br />
any event, the first reaction indicates promising results<br />
which are al Icasi as good as thc previous performance.<br />
REFERENCI<br />
1. J. H. Knowles, Radiology-a case study in technology and<br />
manlipwcr-II. New Eilg. J. Med. 280. 1326 (1969).<br />
2. R. H. Morgan, The emergence of radíology as a major<br />
influence in Anmerican medicine, Am. J. Roentgenology 11l,<br />
449 (1971).<br />
3. National Advisory Committee on Radiation, Protecting and<br />
Inproving Health through the Radiological Sciences-Report<br />
to the Surgeon General, Public Health Service, p. 9. U.S.<br />
Department of Health, Education, and Welfare, Washington,<br />
D.C. (1966).<br />
4. R. Lindheim, Uncoupling the Radiology System, pp. 55, 150.<br />
University of California Center for Planning and Developnwnl<br />
Rescarch, Berkeley. Calif. (1967).<br />
5. G. Revesz, F. J. Shea and M. C. Ziskin, Patient flow and<br />
utilization of resources in a diagnostic radiology department,<br />
Radiology 104, 21-26 (1972).<br />
6. G. Revesz, F. J. Shea, 8. Lev and M. S. Lapayowker,<br />
Computer aided design for improving the delivery of<br />
radiological services, In Planining o/ Radiological Depuartents<br />
(Edited by M. Kormano and F. E. Stieve), pp. 10-106. George<br />
Thiemc, Stuttgart (1974).<br />
7. R. P. Covert, G. S. Lodwick and E. W. Wilkinson, Simulation<br />
modeling of a diagnostic radiology department, Proc. Conf. on<br />
t140n)<br />
(No, .. '\<br />
McCreadie, . .' . Radiology departmenr planning. Hospi¡al<br />
Health and! aarai ?lenA (London) 26, 26 tJulb 1963i.<br />
Nuffield Provinciaí nos, ', Trust. Towards a Ctlarer Vi.'. : Ti,<br />
Organization of DL,. tic X-Ray Departnmitnls. Oxford<br />
University Press. Lond- '962).<br />
Schaefer, J. E.. Temple L...vtrsity Hospital Adminitration.<br />
Personal communication (197;'<br />
Shuman, L. T. and Wolfe, H., A Gen. ....i Model for Hospital<br />
Micro-Costing. University of Pittsburg Press (19702.<br />
Theusen, G. J. and Sullivan, W. G., Cost sensitivity analvsis for a<br />
radiology planning problem. Proc. 39th Naot'. ORSA Meeting,<br />
Dallas, Texas, May 1971.<br />
Trecate, A. and Zoboli, C., Elements in planning a radiology<br />
department for a general hospital, Cliniche Moderne (Milan J I.<br />
I17 (Jily/Aug. IX11I).<br />
Warner, T. N., Use of simulation to generate sheduling heuristics<br />
in a diagnostic radiology deplrirnent, Master's 'hcsis. MIT<br />
(1968).<br />
Welch, J. D. and Noble, D., Functional stud;ies in hospitals and<br />
particularly in X-ray departments, Riidi;,,kgy ILondon ) 27. 131<br />
(May 1961).<br />
l"' stm;n. C. E., Planning of new ,iiagnostic d,' irtnients, Brit. J.<br />
Radiol. 35, 265 (April 1962).<br />
Widegren, G. B., Georgia ' 'utJe ,' i'echnology, Personal<br />
communication (1971'<br />
- 115 -
1,#<br />
- 116 -<br />
Program Evaluation Techniques in the Health Services<br />
Abstract: This article addresses the issue of program<br />
evaluation in the area of heaith services; examples<br />
are drawn from the field of mental health. Current<br />
arguments concerning the goals, characterisiics. ;iad<br />
methodologies of prograni evaluatlion are discusscd<br />
Introdtc'tlio1<br />
Program evaluation is currently a subject of major attention<br />
in the health services field. Much of this attention has<br />
centered around the definition of "evaluation" itsell'. Simply<br />
stated. the purpose of evaluation is to lind ouit what worked,<br />
what did not work. and why.' However. the proper use of<br />
the evaluation restilts is frcquently a source of disagreement.<br />
Levey and Loomba 2 distinguish bctwcen on-going evaluation<br />
and rctrospectivc evaluation as follows: The purpose of<br />
on-going evalualion is uo iiieasttre prugre'ss lowrd prograni<br />
goais so as to direct control over a programn. In contras.t, relrospective<br />
evalutlallio is coniidteled lt detler't ille Ilc elYleccl of<br />
a prograni so as to facililile program IplRlnintg.<br />
If. as is generally accepted. prograim valuation is the determination<br />
of the degree of progress in achieving program<br />
objectives. then cvaluiation is a tool for control. However.<br />
there also exists the opposite view-that tihe consideration<br />
and evaluation of predetermined gouals is nol only unnecessary<br />
but also possibly contaminating." Thc concern here is<br />
thai the evaluator will develop tunnel vision hy accepting Ihe<br />
validity of tlhe prograni goals and Iiis overlook olhlir. per'haps<br />
more importalnti. cll'ects ol' hc pl'gl'ln. 'IThis viewpoiii<br />
of evaluatioun as an uinbiased (iii itermis oi Ihe progrilla's<br />
Address reprint requesis to Dr. Jack Meredith. Associate Professor<br />
of Management. Florida In.rnational University. Tamiami<br />
Trail. Miami. FL 33199. Tlhis paper~ias submitied lo Ihe Journal November<br />
17. 1975. revised. and accep!ed for putblicatlion June 1. 1976.<br />
AJPH November. 1976, Vol. 66, No. 11<br />
JACK MEREDITH, PHD<br />
and two generally useful quantiative evaluatlion models<br />
are.presented. The models are compared and their<br />
advantages for clinicians and administrators are detailcd.<br />
(Am. J. Public Health 66:1069-1073, 1976)<br />
goals) analysis thus appe;ars to place evaaliuaion a;is ;ilIpttin,,R<br />
a<br />
tool .<br />
There is no need to make a choice heíween these t%-o<br />
viewpoints. Evaluation can. and should. be used for both<br />
planning and control aund thus serve as an all-important feedback<br />
link bctweei tliese cruciail 'unctions.<br />
This paper compares two general-purpose programn evaluation<br />
models that can be used for both planning and control.<br />
The models are ilhistrated with applications in the complex.<br />
ill-defined area of mental health. To ililstrate the models<br />
i¡ is asstimed llh;i psychiatric ciaes can be specified<br />
objectively. outcome criteria can be designated anid agreed<br />
iupon. Irealment progranis remain silable. anmd patient selectiol.<br />
e¢tlr C lllen selccjtioll, ;antd (lll tside ilnllCll¡cce ;ar'e controlled<br />
or accounted for. Clearly. Ifew situations will satisty<br />
all these assumptions and ltius the models' outputs must hbe<br />
tempered with experience. judgment. intuition. and other<br />
quailitautivc flactors hefore a linal decision is reached. If so<br />
tempered. such models can provide important information<br />
tor the clinician or administrator.<br />
All Index Model<br />
The first model. adapted fromn Haipern ;aed B3iner.' is<br />
;ain indlx Inotlcl th;it cximfilles prog;lan's l cllectiveiess<br />
(how W,1. it tachieves its goa;s) and its eliciencs resuils per<br />
unit coD. Sulmmalry ralios lor these two meal ;' are developed<br />
!p program value and prograni co ,ta. Mental<br />
hcalth lograms may result in changed Jindi ftinctioning,<br />
in irvention. and protection of the indi 1ufI.! andior so-
MEREDITH<br />
- 117 -<br />
ciety. However. change in the functioning of the individual is<br />
pcrhaíps thc le osl impoirtant restilt.<br />
A sturroga.e ncaistl' c of thie v;alue of individu: d func'iolling<br />
is suggested hy Ha;lpcrn and i3inner. hbased on the individual's<br />
primuary nicanis ol'contíihuting io society: his economic<br />
productivity. Since the pitieni's niost recent economic piodutctivity<br />
ima;y ac¡¡irel lynol reillclct tii polcntlial duc Io his<br />
current mental handiciap. his ecoioinic píodiuclivily is bcased<br />
instead on (he average of his previotus 12 months' earnings<br />
and the expected annual earnings of iin average member of<br />
his cducaiional and *cctipatioinal peer groip. Annmilal earnings<br />
is used, rather thaln lotael expecel d fulur earnings. ¡o aidknowledge<br />
the general impermainencc of the improved level<br />
of functioning due to the program. A lower hound on earnings.<br />
the mininitim annuail wagc. is impossed to reflecl society's<br />
intplied mniniial worilh of ill iiitdividlis. 'I'his ohviales<br />
the dillictiltics of infl'cring a wage loi' housewives. students.<br />
the severely retarded, children. tile retired. and other<br />
such groups.<br />
'l'hc thought of usiFng ;.ll individutil's lirsonllal cuolioiice<br />
productivity as a surrogate for progrant value may be anathema<br />
to some because this suggests accepting only the rich or<br />
the working male into trealment programs in order to obtain<br />
the niost cos(-ctl'ccivc prograrms. Thius. a miore desirable allernative<br />
may be to utilize tile mcan national (or regional) income<br />
so as to equally value all patients. Another alternative<br />
would be to develop monetary values based on broader oncepts<br />
than wagcs. For simpliciíy's sake. however. we will illustrate<br />
the example here with individual economic productivity.<br />
The surrogate measure of improved functioning is then<br />
the product of'the patient's average annual productivity and<br />
an index of cltige. * TIhc index of change is a rough meastire<br />
of the effect of the program on the individual. Table I lis-<br />
TABLE 1-Specification of Indices of Change (A Model Input)<br />
Discharge Level of Impairment<br />
Admission Level<br />
ol Impairment None Siight Moderate Severe<br />
Slight +404 0 -30%/ -70%<br />
Moderate + 70%" +40% 0 -30%<br />
Severe +100'/o +70% +40% 0<br />
NOTE: 100 per cent or 1.0 represents progression trom severe impairment<br />
to no impairment. 70 per cent or .7 trom moderate to none. etc. Level of<br />
impairment calegorizaion is pro orabty detormined by place on a standardized<br />
acate whose reliability and validity have been eslablished.<br />
some exaniples ol' itndices olf change. n a gross scale. a;s a<br />
function ol inmpaimitinent ;il aldission imand disclihige.<br />
Table 2 presents hypothetical data t'or an Incarceration<br />
programni serving thrce individuals to illustrate the decter,<br />
tion of program value. The index of change is based on columns<br />
(4) and (5). The program value is then based oin this<br />
index of actual change in column (6) and ihe av erage productivily<br />
in columnn (3). 'I'e overall progr;IIt vathle index coinputed<br />
in (he table. 477. is conimputed on aier patienri hasis so<br />
as to be comparabhle with other progranms. The m;iximnunl programni<br />
valie possible in colmnin (9) is fotund in the sante manncir<br />
;is the I'ptgraii valiue ill colun>lniii () il li ( i nti¡e\ .or Io1sible<br />
change is used instead of the actual. Thus. the index of<br />
possible chalinge for Individual I whose admission level was<br />
moderatie is. from Table 1. 70 per cent (discharge level of<br />
nonc). I:or Indlividuail 2. ihe ntmtsinium is 10'1 per cent. and<br />
for Individual 3. it is ihe same value as before. 40 per cent.<br />
Program cosis are more straíightforward. The only difficulty<br />
here is the decision of whether ¡o charge the program<br />
with onily dliec¡ cosis or whelher ¡oi inchide indirecc costs a'S<br />
well. 'f the patient spent díill'centi ;inl1lts ol' tilme ill dil'erent<br />
cosl sialuses (hospital. Ifamily care. ouipalient) within a<br />
program. a total cost figure may be obtained by multiplying<br />
thie days spent in each stlilus hy lhe dalily cost of the sltitus<br />
and then summing over all staluses.<br />
Table 3 presents the hypothetical summary program<br />
evaluation indices for an agency with t'our drug treatment<br />
programs. The incarceration program's values. columns (2) &<br />
(3), were derived from Table 2: the values for the remaining<br />
programs would be derived in the same manner. These numbers<br />
are interpreted in relation to annual wages-the treatment<br />
home saves three times the per patient wages as incarceration<br />
(1,510 vs 477). Thie maxinmum possible value per<br />
program is shown in column (3 fIor comparison with coluimn<br />
(2). Thus, incarceration saved 477 out of a possible 4.480<br />
while methadone maintenance saved les 450. but out of a<br />
much smaller possible. 1.753. Thus. melhau 'e maintenance<br />
is less efl'ective than incarcerajion in ternis uf ';iblohlt vailue<br />
more n: effective in relation to its potential. as shc wn by Ihe<br />
efft ---ss index in column (6).<br />
C '
- 118 -<br />
TABLE 2-Example of the Determination of Program Value for Incarceration<br />
EVALUATION TECHNIQUES IN HEALTH SERVICE<br />
(1) (2) (3) (4) (5) ((?5 (6<br />
(6) (9)<br />
Index ol<br />
Poss. Change Pgm. Value<br />
Previous 12 Group Ave. Avg. ol Admission Discharge Index od (Discharge Pgm. Value Pos»sab<br />
Month's Earn. Annual Earn. (1) & (2) Level Level Change Level od None) (3) x (6> (3) x (7)<br />
Individual 1. 7.400 11 000 9.200 Mod. Severe - 30% a 70% -2.760 6.440<br />
Individual 2 4,680' 4,680 4,680 Sev. Mod. +40% + 100% 1,872 4,680<br />
Individual 3 5,100 6,500 5,800 Slight None +400% + 40% 2,320 2,320<br />
Total (T) 1,432 13,440<br />
Avg. = T/3 477 4,480<br />
*Based on a minimum wage dl $2.00 per hour.<br />
ioxili;calioln. ;lilhough lnot exremenly cllictivc iii tcl's oí' ils<br />
potential. is ani exlrmnicly elliciien prograin. Wc mighl thercfore<br />
mniove o cxpand t'realment hoeilos al Ihe expense of' incarceralion<br />
aínd try to improve the etlectiveness o ni mehadoane<br />
deloxilicaiion.<br />
1' ablc 3 c.an also givc overall ellicicnlcyaiid cll'clivenccss<br />
indices for the agency's four programs. These are lound by<br />
multiplying each program index by the number of patients in<br />
that program (column 1) und then dividing by the tolal group<br />
sizc:<br />
Overall<br />
Agency<br />
Elliciency<br />
.82x3 + 1.16x57 + I.28X81 + .76x 163<br />
3 + 57 + 81 + 163<br />
= .97<br />
Overall .11 x3 + .6X x57 + .34x81 + .26x 163<br />
Agency 3 + 57 + 81 + 163<br />
Effectiveness<br />
= .36<br />
The poor performance of incarceration is minimized in the<br />
overall indices due to the small number of patients in that<br />
program. In terrns of efficiency. the agency is saving almost<br />
as much. in terms of patient productivity. as the program<br />
cost. The cellectiveness ol' .36 indicales Ihail they are achieving<br />
about onc-third of the maximum possible achievablenot<br />
necessarily a poor showing.<br />
'I'his cxaimple has comparetd Jill'cent progrants hbu Ihe<br />
same model can also be applied to the same program al dillerent<br />
time periods or lo grouLps of patients categorized by<br />
means other Ihan treatment programs: e.g.. by sex. age. or<br />
diagnosis.<br />
Ha;lper'n and Binner 4 point out une of' the inevitable argu-<br />
AJPH November, 1976, Vol. 66, No. 11<br />
mcnis agauinst the index evailiaition model when they) stite<br />
1hil; "... .. ileao ;tlllilI liillof ¡ . a f it iieieil1 Ihe;illih proglra;il mi;ly<br />
not he able to mnax;inmize his 'relurn oni investment. In fiac. he<br />
maiy have lo follow s;ctleics thhail lower hi. reliurn. if he is lo<br />
serve those who need his hclp most." IThis. of course. raises<br />
a tlinidamclal;l quelilon: WVlo hlhold 'cl ccive tihe hem:fit of<br />
¡he program's limited res'ui'ccs For exaimple. bhould ¡he<br />
patient who can utilize them the niost receive the resources<br />
or the patient who needs them the most? There are no meth-<br />
Mlological or technical answers to such moral and ethical<br />
quest ions.<br />
Tlie M'ra'kov Ciin MoIdel<br />
TABLE 3-Drug Treatment Program Evaluation índices (Hypothetical)<br />
'<br />
Eyman's' 1 siatistical evaluation model. the lMarkov<br />
Chain. differs significantly fiom that of H:alpcrn and Binner<br />
in that it focuses exclusively on the functional level of ¡he<br />
patient. using it as the measure of chainge and ihe basis lor<br />
cvallation. T'he Markov model delineates. via contingeicy<br />
tables. the movement of the patient (or groups of patients)<br />
along a scale in terms of the patient's initial position on the<br />
scale.<br />
Eyman used the Marlkov model io evaluaate the efl:ctiveness<br />
of a school progranm antd ain inteinsive treatment program"<br />
in a hospital for the mentally retarded. I-owever. the<br />
Markov modcl is much more powerl'ul than these limited applicalions<br />
suggest. FoI example. as ,¡ill be shown. program<br />
costs can be included in the model so that it has the potential<br />
of being combined with the index model advanced by Halpern<br />
and Binner. In addition. under very general condilions<br />
the model has been used' s<br />
to predict the probable time-<br />
(1) (2) (3) (4) (5) (6)<br />
No. ol Pgm. Program Pgm. Eliciency Ellectiveness<br />
Program Palienis Value Value Poss. Cost Index = {2)/(4) Index = (2)/(3)<br />
Incarceration 3 477 4.480 583 .82 .11<br />
Treatment Home 57 1.510 2,205 1,300 1.16 .68<br />
Methadone<br />
Detroaification 81 975 2,870 760 1.28 .34<br />
Methadone<br />
Maintenance 163' 450 1,753 590 .76 .26
I<br />
MEREDITH<br />
- 119 -<br />
varying oulcome of a trealment program on a patient. Furthermorc.<br />
the modcl can handie more than one treatment<br />
progralm ll a lime so as sequential varia
TABLE 6-Expected Change In Cohort Distribution from 1970<br />
to 1974 with Varying Treatment Programs<br />
1974 Ablily Gfoup<br />
I 1I IMI tV V VI D<br />
1970 .- --<br />
Athlly 1 oliil<br />
Group Pahlenis 89 72 95 133 1 18 .I- bO<br />
í 221 73 46 46 27 11 0 18<br />
II 112 12 16 26 27 19 3 9<br />
111 114 4 9 18 34 32 8 9<br />
IV 96 0 1 3 30 36 18 8<br />
V 52 0 0 2 14 18 14 4<br />
Vl 20 0 0 0 1 y 15 2<br />
O 0 0 0 0 0 0 0 0<br />
tion he will have in any future year he desires frtom which he<br />
1may dctcrminuie whal resotirces he will neeccl to service those<br />
patientis ofl' ourse. distaiit protjeclions haive .ess reilialbilily<br />
than near projections.<br />
Table 6 was generated. specifically for the 197(1 cohort<br />
shown. fronm ai fiur-yeair probability matrix sintilar- o tilhat of<br />
'I';ablc 5. Th'le next tIluce sets of' s .lupplcntli y inl'ornillion<br />
are all shown in Tahblc 7. This table lisls the nimlber ol' years<br />
a patient is expected to spend in each of the groips belfore<br />
either dying or being placed in a community loster home (limited<br />
to Grotip VI as per T'l'ihe 5) li'r the firsl time. 'The total<br />
cost the patient is expecled to incur lip to itis eveni is also<br />
shown and was derived hy multiplying the yeairs spent in<br />
each group by the Unnual cost ol' the prograin selecied lfor<br />
that group (from Table 5). L.;istly. the table gives the probability<br />
of each of the outcomnes occurriíng lirsl.<br />
Table 7 shows. for example. that a patient in the lowest<br />
ability group (I) is expected to spend 4.4 years in thai group.<br />
including time spent there due to regressing from higher<br />
groups. abhot two and one-hall' year.s in Groups II aund 111<br />
each, and about lfoutr and one-half yeai;s il Grotups IV ;and V<br />
each before he either dies or is placed in a l'oster home. for a<br />
total of 18.3 years spent in the hospital at a total cost of alnmost<br />
$18)0.Wf. 'T'he likceilhood is ;ianlosl Iwicc as gilc;al ilitla Iic<br />
will be placed in a foster home ralther than dying first. a very<br />
positive prognosis for a patient in this group.<br />
TABLE 7-Expected Stay Times in Years with Varying Treatment<br />
Programs Until Either First Placement or<br />
Death<br />
Outcome<br />
Abilily Group Total Probability<br />
1970 . .........-<br />
Ability Place-<br />
Group 11 il IV V Years Cost (S/Pat) ment Death<br />
I 4.4 2.2 2.8 4.6 4.5 18.3 179.500 .64 .36<br />
II 1.1 2.8 2.6 4.9 4.8 16.2 166,400 .68 .32<br />
111 0.4 0.9 3.2 5.1 5.1 14.6 155,400 .71 .29<br />
IV 0.1 0.2 0.6 5.6 5.4 11.9 130,900 .76 .24<br />
V 0.1 0.2 0.6 3.9 5.8 10.5 113,000 .79 .21<br />
AJPH November, 1976, Vol. 66, No. 11<br />
- 120 -<br />
EVALUATION TECHNIQUES IN HEALTH SERVICES<br />
Lastly. the Maitkova molel is not limit to ti ealinlgíed e'aitli;iiing only<br />
Ihose progranms ' ith which ain ;igenc\ h;, erperience. For<br />
insl;ince. il' ; ne%' moule ' opel';ran c'onditioning hecome%<br />
av:d"l;¿lt oruh ;t a llotili;ítiil lo ;ill e\ ninI lllg pr'gra;l i' con-<br />
Ceílípliatcd. stlbjcctivc etli; iate', ofl the t'rlnmsition probahililíes<br />
coulltd CqUlly %%t l ¡le ued' iii l tihe lI';tií,i¿ito prolablilty<br />
m;itrix. 'i'hc eiffect otl'tlihe neA o modiied i prog'ailln coild ihen<br />
I, lc .' i '.itiiii c t ill at iil tllf Nilli ;it i ¡'la';,I es I ;ia ld 7. ''hli,<br />
woutld also give thc eIl'eet oin the total coNt t ttihe hospilal antl<br />
tiltis asclrie ;an equivllentl wsorth to the progra;in.<br />
Disc'..ss.ion<br />
Although the Markov model and the Halpern and BIin-<br />
¡ner nilldel Irc.ilirel ;, Cnllsidetrail;ae aimnilUSt of' ell'aortl io Ise.<br />
evenl more el'ort is requictd Ilo provide aleculrlic. Inc;lninigltll<br />
iiiput daia l'for t¡le niodels. Clc'ily. the st;tirticmal ni:;miptil.'tion<br />
of inacctirate daita¡ is % 'orse thani useleC -il may veil he<br />
mi:slalding. Tlhus. to ¡ise these imotels for tile pu'pose they<br />
were intended ieqtii'¢cs ami ciis.II'mots O ;illl¡tiilt tf sstmk re'l'tll<br />
ascertaining the reliability andt validity ol'f the rawv dtta. In ¡tddition.<br />
an appropriate scoring aníd recoe'ding sy>stem must be<br />
designed. monitore(d. and properiy titilized. And finally. the<br />
rcstulis of ithe ilodel ;,, ;ailyacs i¡lil Isc iierprei.ted ;antd very<br />
carel'tilly expl;ined IeNs ineoire.1le inl'eirences he dtirir n.<br />
Ftl'hernmore. l*iy ev;.ll;ion model is onlly one lootl in<br />
the total program evaitiation process. ''hc M;uiinko mnudel<br />
;aiid tlíe Il;pilcpiin ;and li inlsicr modeili l ;icl'cr;l' It' e es¡pci;allv<br />
useli.l inii this regai'd. U nodouitedly . moex ;ilitíivíon ilmdetJls<br />
for the hcalilh services swill he dcv eloped and i.come ;v;,ilable<br />
as time progr'esses buit hliing lihc interinm the [v.t nmodels<br />
described here appear' to prose,,,, the moni genieral applicaibility<br />
Cfor qua;italivic plrogratil xi uatltioi. \\'hen ti.ed in<br />
conjunction with additionail quatli;iltiye intirmnaition and real<br />
world constraints these models should prove ecxtremely helpful<br />
to Ihe cliniciains and health atdlminiNitratir'n lced wJith the<br />
task'ol' progri'am evaltition.<br />
REFERENCES<br />
1. Weikel. K. Evatliuation of naiional hellh progranis. Am. J. Public<br />
Health 61:1801. 1971.<br />
2. Levey. S. and Loonmh;a. N. P. Healih Care Admninisilalion. p.<br />
421. I.ippincoll Co.. 1973.<br />
3. Scriven. M. Goal-iree evaluation. Evaui;atlio 1:b62. 1973.<br />
4. Halpern. J, and Binner. P. R. A model for a¡n ouipUt valuc anatlysis<br />
of inmenlul health programs. Administra;tion in Mental Health<br />
1:40-51. 1972.<br />
5. I:yniain. R. K.. T;arj;iil. G.. and McGlmnige. I). The Mitrktov<br />
Ch.i¡in as ;, Ilctilhod kt, eví.Islitiíg s.hotols ¡for ihe mlenal;lily re.<br />
atl. edAm. A . Menial I)cliciicny 72:435-144. 1967.<br />
6. LEyrií;ma. 1. iK.. Iaiij;an. C;.. ialnd CaIsady l. NI. N;ailurail hIisitary fl<br />
aícquisition of basic skills bh hospila;lize reitrided palienls. Am.<br />
J. Mental Deficiency 75: 120-129. 1970.<br />
7. Meredith. J. A M:ikwia .il5na'!is i ot ai ge;.Jitiic %ya;rd. M;anagenient<br />
Science 19:(1( 4-612. 1973.<br />
8. Meredilh. J. Prograni evalualtioun in a htopit;ll for ¡ihe ment;all relarded.<br />
Am. J. Menitl Deficiencv 781:471-48I1. 1974.<br />
9. Kemeny. J. C. and Snell. J. 1.. Finile Miarkov Chaiins. D. Van<br />
Noslitrnd. 1960.
MEDICAL CARE<br />
,arch 1981, Vol. XIX, No. 3<br />
- 121 -<br />
Assessing the Performance of Medical Care Systems:<br />
A Method and Its Application<br />
PAUL A. NUTING, M.D.,* GREGORY 1. SHORR, M.D.,t<br />
AND BARTON R. BURKHALTER, PH.D.S<br />
As health care becomes more differentiated, fewer people receive the majority<br />
of their care from a single source. Yet, most methods for assessing health care<br />
focus on the care provided by a single facility or group of practitioners. A<br />
method is described which tracks individuals through the diffuse medical care<br />
"system" and examines the process of care received for complete episodes of<br />
care. Through the use of tracer conditions the individual's pathwAay through the<br />
system is followed and the contribution of the various system components (e.g.,<br />
facilities and providers) is assessed for various funetions of care (e.g.. sereening,<br />
diagnosis, treatmnent), thus pinpointing deficiencies in the process of care. The<br />
method is designed to sample systematically from the entire provider and consumer<br />
system. Use of this methodology in a variety of settings, including<br />
American Indian communities, has proved to be feasible and has uncovered<br />
deficiencies in the delivery of health services which might have been overlooked<br />
by other approaches. This article describes the assessment method and<br />
presents selected results which demrnstrate the assessment outputs.<br />
AS TECHNOLOGY and specialization increase,<br />
consumers of health services are<br />
faced with a bewildering array of different<br />
individual and institutional provide -<br />
with ever fewer receiving their care frorm a<br />
single source. Solutions to the problem are<br />
' Associate Director for Research, Office of Research<br />
and Development, Indian Health Service,<br />
Deparbntment of Health and Human Ss. ices.<br />
f Director, San Xavier Ambulatory Care Project, Office<br />
of Research and Development, Indian Health<br />
Service.<br />
t Senior Scientist,' Community Systems Foundation<br />
and Professor (Adjunct), Departnent of Family<br />
and Community Medicine, University of Arizona.<br />
All opinions expressed herein are the authors' and<br />
do not necessarily represent the policy of either the<br />
Indian Health Service or the Department of Health<br />
and t!uman Services.<br />
Address for reprints: Paul A. Nutting, M.D., Associate<br />
Director for Research, Office of Rescarclh and<br />
Development, Indian Health Service, P.O. Box<br />
11340, Tuicson. AZ 85734.<br />
0025-70791811030010281/$01.30 O J. B. Lippincott Co.<br />
offered from at least tv'o philosophical<br />
viewpoints. Some argue that tect, logy<br />
and specialization should be decrit ed<br />
and the goals of the health care system<br />
- 'ised to give more control to consumers<br />
an . -- attention to the environment and<br />
style: c 'iving,'-5 while others find<br />
evidence i the high degree of specialization<br />
shou!-' be maintained and better<br />
management auc ed to it. 6<br />
Methods of qua;'' -- 'essment and assurance<br />
may eventually contribute to better<br />
management of health care rystems.<br />
However, quality assessment and assurance<br />
have yet to demonstrate their worth.<br />
Most assessments ofthe quality of care address<br />
only narrow segments of the complex<br />
array of services. Some focus only on the<br />
care provided by single facilities or groups<br />
of providers. Others focus only on care<br />
proviaed to those patients who have
NUTTING ET AL.<br />
sought care for specific health problems.<br />
Most emphasize only diagnostic and<br />
treatment functions.<br />
More comprehensive methods are<br />
needed. This article presents an approach<br />
to quality assessment 'which tralcks members<br />
of the community into and through<br />
episodes of care provided by various parts<br />
of the medical care system.<br />
Requirements for Quality Assessment<br />
in the Indian Health Service<br />
The Indian Health Service (Department<br />
of Health and Human Services) has<br />
evolved a complex system of health services<br />
delivery. Charged by Congress to assure<br />
comprehensive health services to<br />
more than 600,000 American Indians and<br />
Alaskan Natives, the Indian Health Service<br />
(IHS) has developed and is operating<br />
more than 85 local comprehensive health<br />
care systems, called Service Units. The<br />
typical Service Unit serves a dispersed<br />
population, often scattered over severaithousand<br />
square miles. It usually consists<br />
of a 30-50 bed hospital and outpatient department<br />
staffed by a variety of health professionals<br />
and administrative staff. The<br />
main Service Unit facility serves as a referral<br />
center and administrative base for<br />
one or more full or part-time field clinics,<br />
public health nurses, environmental engineers,<br />
health educators, and a variety of<br />
problem-specific health programs (nutrition,<br />
mental health, maternal and child<br />
health, alcoholism, etc.) operated by the<br />
tribal government. Each Service Unit can<br />
also refer patients to secondary and tertiary<br />
care centers, either operated by the Indian<br />
Health Service or through contract within<br />
the private sector.<br />
As Service Units have grown more complex<br />
and Indian communities have become<br />
more mobile and more active in health delivery<br />
programs, the methods traditionally<br />
used by IHS to assess and assure the<br />
quality of care have become i. adequate.<br />
Therefore, the Indian Health Service has<br />
- 122 - MEDICAL CARE<br />
undertaken a long-term research and development<br />
effort in the assessment and<br />
assurance of quality.<br />
In an earlier study in one Service Unit,<br />
patients were tracked through episodes of<br />
ambulatory care for several prevalent<br />
health problems. 7 The study demonstrated<br />
that 1) explicit criteria for minimal care<br />
could be defined by the Service Unit<br />
physicians; 2) reliable data could be collected<br />
retrospectively from medical records<br />
by nonphysicians; 3) failures in the<br />
process of care could be identified; 4) the<br />
failures tended to occur at the same places<br />
in the process of care for different health<br />
problems; and 5) this information caused<br />
the Service Unit to take action aimed at<br />
correcting the problems.<br />
As a result of this experience, eight requirements<br />
were defined which, it was<br />
felt, would make the assessment method<br />
applicable throughout Indian Health<br />
Service.<br />
First, the assessment must examine the<br />
performnance of the total health system.§<br />
All facilities, organizational subunits, and<br />
programs providing health services within<br />
the community should be included<br />
whether or not the individual components<br />
consider themselves as a part of a "system."<br />
The contribution of physician extenders,<br />
pharmacists, public health nurses and<br />
community health personnel as well as<br />
phSysicians should be included. The combined<br />
effect of consumer and provider on<br />
system performance should be measured.<br />
Second, the assessment must examine<br />
the care received by all members of the<br />
community, both patients and nonpa-<br />
4 The total health system contains the consumer<br />
subsystem and the provider subsystem. Much of our<br />
attention focuses on the medical care system, which<br />
we define as that part of the provider subsystem providing<br />
medical care. Components refer to the varinous<br />
parts of the two subsystems. For example, the assessment<br />
examines three types of components in the medical<br />
system. including facilities, organizational subunits<br />
and professional disciplines, although other<br />
components could also be identified.
%,I. XIX, No. 3<br />
iclnts. It should determine :i .Yrta±.n<br />
groups, especially those at high risk, ,tijv<br />
lower quality of care than others.<br />
Third, the assessment must examine, it '<br />
,erformance of the'system across .. broad<br />
rangec of functions." In addition to diagníosis<br />
and treatment, system performance<br />
fr,. other functions such as prevention and<br />
u.rcening should be examined also. Altlia
NUTTING ET AL.<br />
- 124 -<br />
for the tracers as a group is similar to all<br />
care, and assumes that efforts that improve<br />
deficient care in the tracers will also improve<br />
care for other similar conditions, although<br />
these assumptions are not yet supported<br />
by experimental evidence.<br />
Consistent with Kessners use of tracers<br />
in sets, rather than singly, the assessment<br />
aggregates data by function across the tracers,<br />
in order to focus corrective action on<br />
function rather than disease.** The funetions<br />
we have used-prevention, screening,<br />
health status monitoring, diagnostic<br />
evaluation, treatment planning, follow-up<br />
and ongoing management-can be recombined<br />
to fit the needs of a particular<br />
analysis. Other functions, such as patient<br />
education or rehabilitation, can be defined<br />
if desired.<br />
Most functions can be separated into<br />
three sequential events, namely, contact<br />
between a consumer and a provider, recognition<br />
of the need for service once contact<br />
is made and provision of service after<br />
contact and recognition. Th ' particular'<br />
classification of functions and sequential<br />
events was chosen because it is generally<br />
familiar, because the adaptive processes<br />
required to correct deficiencies would appear<br />
to differ by funetion and event, and<br />
because the Indian Health Service may be<br />
in a position to influence these categories<br />
'* The data for a particular function are aggregated<br />
by 1) summing the number of consumers found to be<br />
in need of care in the study cohort of each one of the<br />
tracers; 2) summing the number found to be receiving<br />
adequate care in all tracer cohorts; and 3) dividing the<br />
second sum by the first to obtain the fraction of consumers<br />
for all tracers who are receiving adequate care<br />
for that function. This procedure weights the tracers in<br />
proportion to the size of their cohorts. Usuallyfthe size<br />
of the cohorts have been in proportion to the prevalence<br />
of the tracers, that is, the number of consumers<br />
in need ofcare for each function of atracer, although in<br />
some cases cohort sizes for all tracers have been equal.<br />
The aggregating procedure assumes that when the<br />
racers are weighted in proportion to cohort size, the<br />
care received for the tracers is representative of the<br />
care received for all health conditions. However, our<br />
experience indicates that this assumption is not always<br />
justified and that care should be taken in interpreting<br />
aggregated results.<br />
,1 3<br />
MEDICAL CARE<br />
of activities. This classification may be altered<br />
as more experience is gained with<br />
pattems of homogeneity across tracers and<br />
with their usefulness in improving care.<br />
When carrying out a particular assessment,<br />
we define an assessment spacet<br />
that is delineated by the functions, tracers,<br />
systemn components and populations to be<br />
studied. By defining the assessment space<br />
and measures of performance first, the assessment<br />
focuses only on issues of interest.<br />
Table 1 shows the functions and tracers<br />
that we used in early applications of the<br />
assessment method. Every function is<br />
examined using at least two tracers, by aggregating<br />
the data across the tracers for<br />
each function. This particular assessment<br />
space was constructed to examine common<br />
issues in ambulatory care, and did not address<br />
care for mental health problems,<br />
medical or surgical problems requiring<br />
specialized care, or rehabilitation. Since<br />
many of the functions are further broken<br />
down into the three sequential events of<br />
contact, recognition and provision of required<br />
service, the assessment space permits<br />
analysis of patient utilization, system<br />
outreach and problem recognition. However,<br />
this assessment space does not allow<br />
for analysis of inappropriate utilization of<br />
inpatient or outpatient services, surgical<br />
procedures or inappropriate drug therapy.<br />
For each tracer, minimal criteria for the<br />
process of care are established for each<br />
function which the tracer examines. In no<br />
case was a tracer used to examine a function<br />
for which "valid" criteria were unavailable<br />
or for which the criteria originally<br />
proposed were questioned by the local<br />
providers of care. Only criteria considered<br />
essential for basic health care are included.<br />
Criteria that may apply to a relatively small<br />
percentage of instances are useful in de-<br />
tt The assessment space for a particular assessment<br />
is defined by specifying 1) the functions tobe studied;<br />
2) a set of tracers for each function; 3) the components<br />
of the health system for each finmction; and 4)a population<br />
of consumers (from which an appropriate sample<br />
is selected) for each function of each tracer.
n'ol. XIX, No. 3<br />
- 125 -<br />
tailed examination of specific issues in<br />
health care, but are of less value in attempts<br />
to examine generic system performance.<br />
Since the assessment involves abstracting<br />
data from the medical record, criteria that<br />
are likely to be documented in the record<br />
are more often incorporated into the assessment<br />
design. In general, prescription<br />
data, measurements, lab results and diagnoses<br />
are reliably documented, while historical<br />
data, physical findings (especially<br />
ne gative findings)and education treatment<br />
plans are not.<br />
The assessment method produces three<br />
different types of indicators of health system<br />
performance: population -based indicators,<br />
encounter-based indicators, and<br />
healtlh-status indicators. Poptulation-based<br />
indicators$ I are computed from a sample<br />
of the coninmunity or a patient subset of the<br />
community and express the percentage of<br />
individuals in need of a specific health service<br />
who receive that service within a<br />
specified period of time. They track<br />
specific cohorts of the consumer popul.<br />
tion through the system of health care and<br />
examine the adequacy of the process of<br />
care and how it is distributed in the population.<br />
Encounter-based indicators are<br />
computed from consumer contacts with a<br />
particular component of the provider subsystem<br />
and express the percentage of<br />
consumcr encounters in which a specific<br />
need for service is satisfied. These indit<br />
I For many issues in health care it is not practical<br />
to employ a true population-based indicator, however<br />
desirable this may be. For example, an instructive<br />
Indicator might describe the percentage cl eople in<br />
the community with a urinary tract infection who received<br />
an appropriate aritibiotic withirnan appropriate<br />
time frame. However, short of a special survey to<br />
identify all people in the community with a urinary<br />
tract infection, this subset of the population i[ -arlv<br />
impossible to define. Consequently, the i.....<br />
would more likely express the.percentage of people in<br />
the community secreened positive for a urinary tract<br />
infection who received an appropriate antibiotic<br />
within three weeks. In t.is case the indicator more<br />
accurately might be called patient-based rather than<br />
population-based, although for simplicity we use<br />
population.based to refer to all indicators with<br />
number of individualb in the denominator.<br />
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NUTTING ET AL.<br />
- liE6 -<br />
cators focus on the components of the provider<br />
system such as discipline or facility<br />
in order that their contribution to total system<br />
performance can be appraised.<br />
Finally, health status indica tors express<br />
the percentage of patients f:r whom a<br />
change in health status has been<br />
docunmented. -le.dlth status itidiciltors<br />
should not be equated with rneasures of<br />
incidence or prevalance since the latter requires<br />
a random sampling of the population.<br />
Health staitus indicators, on the other<br />
hand, often reflect change in health status<br />
of selected patient groups, e.g., only those<br />
who were followed up. Since health status<br />
indicators do not distinguish changes in<br />
health status that are the result of health<br />
care from changes related to behavioral or<br />
environmental variables, they should not<br />
be considered measures of the Guteomes of<br />
medical care unless the appropriate causal<br />
relationships linking process measures to<br />
health status have been demonstrated.<br />
Population-based indicators can be constructed<br />
in a sequence in order to examie<br />
the continuity of the process of care,§§<br />
which reflects the extent to 'which<br />
consumers pass successfully through sequential<br />
steps in a defined process of care.<br />
Figure 1 illustrates a sequence of<br />
§§ The continuity of the process of care is defined<br />
as the likelihood that consumers dill receive needed<br />
heaith senrvices, in a proper sequence and within an<br />
appropriate interval of time, and is expressed as a<br />
sequence of conditional probabilities based on empirical<br />
data. This definition derives from Shortell, i " who<br />
conceptualized continuity as the extent to which medical<br />
services are received as a coordinated and uninterrupted<br />
succession of events consistent with the<br />
medical needs of the patients. The term "continuity"<br />
has been used differently. Some authors prefer a focus<br />
on continuity of process such we have done. ' .U L'<br />
while many others focus on continuity of provider by<br />
measuring the extent to which care is received from a<br />
single source or by referral. i " - » Although it appears<br />
that greater continuity of provider results in greater<br />
continuity of process,." Indian Health Service has<br />
often found it difficult to achieve continuity of provider<br />
and therefore has focused its attention on continuityofprocess.<br />
Here. the term"continuity-of-process"<br />
is used todistinguish our usage from other usages<br />
of the term "continuity."<br />
MtIC.d. CARE<br />
population-based indicators for urinary<br />
tract infection from which the continuity-ofprocess<br />
can be obtained for the treatment<br />
and follow-up finctions. The functions are<br />
divided into contact, recognition and provision<br />
of service, and indicators at each of<br />
these sequential events show the flow of<br />
patients throlugh the treatment and<br />
follow-up functions. Patient flow from one<br />
event to the next can be expressed as the<br />
transition rate Pu, where P is the proportion<br />
of patients at event i moving to eventj<br />
during a specified period of time.<br />
Likewise, tle transition rate of patients<br />
through multiple successive events in the<br />
process of care can be expressed as the<br />
product of the intervening rates, and the<br />
dropout rate between any two events, i and<br />
j, is 1 - Pu.I'I By examining care in this way,<br />
the assessnme nt can identify deficiencies in<br />
health systems performance and distinguish<br />
between problems related to provider<br />
performance, those related to patient<br />
utilization of service and those related to<br />
the system itself.<br />
Selection of the study cohorts and their<br />
health records largely determines the extent<br />
to which the assessment examines the<br />
entire community of consumers rather than<br />
those receiving care. As nearly as is prac<br />
tical, the study cohorts are generatec<br />
randomly from the entire community of po<br />
tential consumers. This is especially impor<br />
"" Care must be taken in multiplying together P,,'<br />
obtained from different tracer conditions and differet<br />
cohorts, because patients receiving adequate car<br />
early in the process of care may not be independent t<br />
those receiving adequate care later on. Specificall;<br />
patients receiving adequate care at one stage may al:<br />
be more likely to receive adequate care at another. I<br />
fact, such nonindependence is illustrated in the da<br />
reported by Novick, I ' although it was not explicit<br />
pointed out by him. We have avoided this problem I<br />
calculating continuity-of-process scores only for fun<br />
tions or sequences of functions where we were able<br />
observe the passage of the cohort throughout the se<br />
quence. Thus, our continuity-of-process scores as<br />
observed, not calculated. When greater knowledge<br />
obtained about the interdependence of functions %s<br />
may be able to combine continuity-of-process score<br />
obtained from different cohorts.
1<br />
Vol. XIX. No. 3<br />
- 127 -<br />
tant for prevention, scree¡inxg and health<br />
status monitoring. As an example, a cohort<br />
of women may be selected for examination<br />
of prenatal care by generating a master list<br />
from delivery room logs, birth certificates,<br />
operating room logs and laboratory logs<br />
(searching for prenatal lab work ordered).<br />
W)hen the redundancies are removed from<br />
the master list, a standard sampling<br />
technique is used to select the study<br />
.,e-,. For r any tracers a single document<br />
!¡zly b'e lusctd t.. gt'ler.ltte' age- andaor<br />
sex-specific study cohort. - g., birth certificates<br />
alone may suffice for the generation<br />
of a cohort for examination of infant care.<br />
It also is important to sample from the<br />
most basic source docunient available. For<br />
example, in generating a cohort of patients<br />
with urinary tract infections, it is better to<br />
sample the líaboratory log for patients with<br />
a positive urine culture than to generate a<br />
sample of medical records for patients who<br />
were diagnosed with a urinary tract infection.<br />
The latter technique biases the sam- _<br />
ple in favor of patients who have made<br />
contact and for whom the system has recognized<br />
the problem.<br />
Patients are eliminated from the study<br />
cohort when they do not contribute to the<br />
objectives of the study. For example, when<br />
examining uncomplicated urinary tract in-<br />
.fections, it might be preferable to eliminate<br />
patients with chronic urinary tract infections,<br />
chronic renal disease, urinary tract<br />
anomalies, etc. These characteristics become<br />
apparent in the record review and<br />
patients thus eliminated from the study<br />
cohort may be replaced from the master<br />
list.<br />
Selection of the health records to be<br />
examined largely defines the scope of the<br />
medical care system to be examined. Since<br />
medical care systems usually are not<br />
clearly delineated, judgment is required to<br />
define the system in a way that will produce<br />
useful assessment results. Most assessments<br />
of IHS Service Units' must<br />
examine medical records at the main<br />
PERFORMA.NCE ASSESSMESNT<br />
FIG. 1. A sequence of population-based indicators<br />
for urinary aert infections constructed to examine<br />
the continuity of the process of care.<br />
hospital-outpatient facility and at one or<br />
more field clinics, public health nursing<br />
records, medical records at one or more<br />
referral centers and sometimes health records<br />
from tribal health programs (e.g., nutrition,<br />
mental health or alcoholism). In<br />
applications of the method outside the Indian<br />
Health Service, a similar set of record<br />
types have been included in the assessment<br />
procedure. In an assessment of one<br />
rural private practice, records were<br />
examined from two private practices, the<br />
community hospital, the county health<br />
clinic and the county public health nursing<br />
program.<br />
Audit instruments are designed for each<br />
tracer to extract data from each record for<br />
each individual in the study cohort. The
NUTTING ET AL.<br />
audit instrument documents each contact<br />
between the consumerand any component<br />
of the provider system and captures the<br />
date, location of contact, pro. ider of scrvices<br />
and any of a predeterrined list of<br />
services required to compute the indicator<br />
results for that tracer. Whcn completed, the<br />
audit instrument contains a complete profile<br />
for that consumer of each contact with<br />
every component of the provider system<br />
and each of the relevant services provided.<br />
The results for each of the indicators and<br />
continuity-of-process scores for each function<br />
or sequence of functions can be computed<br />
from the completed audit.<br />
Application of the Assessment Method<br />
The assessment method has been<br />
applied in 20 Service Units of the Indian<br />
Health Service, three rural private practices<br />
and two closed-panel health maintenance<br />
organizations. Selected data is<br />
presented from these appli itions to<br />
demonstrate the major characteristics<br />
of the method and some of the results<br />
achieved.'<br />
The first step in an analysis is to examine<br />
the performance of each function. In one<br />
- 128 - MEDICAL CARE<br />
Service Unit of the Indian Health Service,<br />
both population-based and encounterbased<br />
indicators were employed to<br />
examline the follow-up fimetion, using as<br />
tracers iron-deficiency anemia, urinary<br />
tract infection, laceration of the scalp and<br />
extremities and prenatal care. Table 2<br />
presents the follow-up criteria for each<br />
tracer and the results aggregated across the<br />
tracers. The consumer-provider contact<br />
rate is population based and expresses the<br />
percentage of patients due for follow-up<br />
who made contact with the medical care<br />
system during the time interval appropriate<br />
for follow-up. The encounter-based<br />
follow-up rate expresses the percentage of<br />
patient encounters due for follow-up, in<br />
which the follow-up criteria were. met.<br />
Finally, the population-based follow-up<br />
rate expresses the percentage of patients<br />
due for follow-up who contacted the system<br />
and received the follow-up services within<br />
the appropriate time. The aggregate data<br />
indicate that 71 per cent of patients make<br />
contact with some component of the medical<br />
care system when due, resulting in only<br />
44 per cent of patients receiving follow-up<br />
services. These results suggest that the relative<br />
weakness in follow--up care is the sys-<br />
TABLE 2. Examination of the Follow-up Function With Aggregate and<br />
Tracer-Specific Data<br />
Iron Urinary<br />
Aggregate Deficiency Tract Prenatal<br />
Follow-Up Funetion Results Anemia Infection Lacerations Care<br />
Contact rate<br />
(population-based) 71(921129) 58% (15/26) 63% (19/30) 65% (15/23) 86% (43/50f<br />
Provision of<br />
service rate<br />
(encounter-based) 51% (57/112) 44% ( 7/16) 52% (12/23) 80% (12/15) 45% (26/58<br />
Provision of<br />
service rate<br />
(population-based) 44% (57/129) 27% ( 7/26) 40% (12/30) 52% (12/23) 52% (26/50<br />
Follow-up critena include:<br />
Anemia-All patients placed on therapy should have a hematocrit or hemoglobin or reticulocyte coun<br />
between three and six weeks of the initiation of therapy.<br />
Urinary Tract Infection-All patients placed on antibiotic therapy should have a urine culture or micrc<br />
scopic urinalysis within four weeks after therapy is completed.<br />
Lacerations-All patients with a laceration requiring sutures should have an examination and documente.<br />
statement of wound healing between 5 and 21 days after the sutures were applied.<br />
Prenatal Care-All women delivering should have their blood pressiure documented and an examination o<br />
the uterus between 2 and 10 weeks after delivery.
Vi. .XIX, No. 3<br />
- 129 -<br />
tom' s recognition of and response to patients<br />
presenting when due for follow-up<br />
services, rather than the utilization behIavior<br />
of the patient population. Table 2<br />
illustrUtes lhow data for several tracers can<br />
¡)e aggregated for a single function, and for<br />
sequential events within that function. It<br />
also il>lustrates that the results are not alwuays<br />
similar across tracers. For cxamplc,<br />
the fact that lacerations, with sutures acting<br />
as an apparent clinical sign calling for attention,<br />
produced higher recognition and a<br />
ver)' different pattern than the other tracers,<br />
suggests that it may be possible to devise<br />
more efficient ways of aggregating<br />
across tracers or to categorize health conditions<br />
in a way that allows for more representative<br />
sets of tracers to be selected.<br />
In order to examine the performance of<br />
Ciflerent system components by funetion,<br />
the assessment often employs a<br />
population-based indicator in conjunetion<br />
with an encounter-based indicator that is<br />
disaggregated by relevant system components<br />
as well as by function. Table 3 shows<br />
the data examining infant immunization in<br />
a rural private practice setting, two Service<br />
Units of the IHS and a large closed-panel<br />
PERFOR.\MANCE ASSESSMENT<br />
health maintenance organization. The<br />
population-based immunization rate expresses<br />
the percentage of infants who had<br />
received three DPT and two polio immunizations<br />
by 12 months of age. The<br />
encounter-based immunization rate expresses<br />
the percentage of visits by infants<br />
due for an imniunization in which the immunization<br />
was provided. The DPT immunization<br />
was considered to be due at 2<br />
months of age and to be repeated monthly<br />
until three doses had been given. If, at the<br />
time of a visit, the infant had a rectal temperature<br />
greater than 100.5 ° , then an immunization<br />
was not considered due on that<br />
visit.<br />
Among the infant population served by<br />
the private practict, only 32 per cent had<br />
received three DPT and tho OPV' immunizations<br />
by age 12 months and the<br />
encounter-based indicator revealed that<br />
immunizations were provided on only 22<br />
per cent of the visits for which they were<br />
due. This private practice had assumed<br />
-.. hat infants were receiving their immunizations<br />
from the nearby county health<br />
clinic. But when the encounter-based indicator<br />
was sorted by the physician's office<br />
TABLE 3. Data for Infant Immunization From a Rural Private Practice,<br />
Two IHS Service Units, and One Health Maintenance Organization (HMO)<br />
llustrating the Performance Patterns Resulting From the Assessment Method<br />
Private<br />
Practice IHS-A IHS-B HMO<br />
Immunization rate<br />
(population-based) '2% (26150) 86% (43/50, 56% (28/50) 58% (29!50)<br />
Immunization rate<br />
(encounter-based) 22% (63/285) 46% (179/387) 38% (119/316) 86% (127/147)<br />
Sorted by facility<br />
Medical officer 19% (211112)<br />
County clinic 24% (42/173)<br />
MCH clinic 85% (103/121)<br />
General clinic 34% (70/208)<br />
2 fild clinics 11% (6/53)<br />
Inpatient service 0% (015)<br />
Sorted by provider<br />
discipline<br />
Physician 34% (64/189)<br />
Physician extender 75% (36/48)<br />
Clinic nurse 50% (6/12)<br />
Public health nurse 87% (13/15)<br />
Pharmacist 0% (0/52)
NUTTING ET AL.<br />
- 130 -<br />
and the county clinic, it revealed that<br />
neither location was taking advantage of its<br />
opportunities to provide inmmunizations.<br />
In discussing the results, both sites agreed<br />
that it had assumed the other was responsible<br />
for immunization, and both agreed to<br />
begin immuniizing niore vigorously. An informal<br />
follow-up study by one of the private<br />
practitioners several months later<br />
indicated that the encounter-based immunization<br />
rate had increased three fold at<br />
both locations.<br />
One Service Unit (IHS-A) had a<br />
population-based immunization rate of 86<br />
per cent and an encounter-based rate of 46<br />
per cent. When the encounter-based rate<br />
was sorted by clinic, it was noted that the<br />
MCH Clinic was performing well at85 per<br />
cent, while the general clinic (34 per cent)<br />
and the two field clinics (11 per cent) were<br />
missing many opportunities to provide<br />
immunization. Since most of the missed<br />
opportunities occurred at the general<br />
clinic, the Service Unit instituted a stalding<br />
order for immunizations in the general<br />
clinic.<br />
In the second Service Unit (IHS-B), 56<br />
per cent of the infant population was immunized<br />
by 1 year of age. When the<br />
encounter-based rate of 38 per cent was<br />
sorted by provider discipline, it was noted<br />
that the physicians werte providing immunizations<br />
only 34 per cent of the time<br />
and were commonly referring infants to the<br />
physician extender for well baby care.<br />
Also, 52 of the 316 infant visits made when<br />
an immunization was due had been to the<br />
pharmacist, who had recently begun a<br />
program providing nonprescription medication<br />
directly from the clinic pharmacy.<br />
This result and the pattern apparent for<br />
other functions led to the development of a<br />
checklist of potential service needs for<br />
prevention and chronic disease surveillance<br />
for use by the pharmacist while dispensing<br />
over-the-counter medications.<br />
A contrasting pattern wa. seen in the<br />
immunization indicators for the health<br />
maintenance organization. Although the<br />
providers were immunizing infants on 86<br />
per cent of the visits when an immuniza-<br />
NIEDICAL CARE<br />
tion was due, only 58 per cent of the population<br />
was being immunized. This pattern<br />
suggested that patient contact was the<br />
limiting factor in achieving higher immunization<br />
rates in the infant community.<br />
This was later confirmed by a study of the<br />
utilization pattenl of the infants, which indicated<br />
that many of the infants contacted<br />
the provider system only when they were<br />
ill.<br />
The above experiences with immunization<br />
illustrate several benefits of the assessment<br />
method. It can focus attention on<br />
a particular site or discipline; it can point to<br />
areas where deficiencies are greatest; and<br />
feedback of the results may, in some cases,<br />
generate action. Several limitations are<br />
also illustrated. The method does not identify<br />
the causes of the deficiencies; it does<br />
not uncover and analyze the many possible<br />
remedial actions; nor does it evaluate remedial<br />
actions during and after implementation<br />
unless a separate study is<br />
undertaken.<br />
In several applications, treatment and<br />
follow-up were examined by obtaining the<br />
study cohorts from the laboratory logs of<br />
each laboratory at every study site. For<br />
iron-deficiency anemia the study cohort<br />
included individuals with laboratory records<br />
showing a hematocrit less than 33 vol<br />
% and a hemoglobin less than 11 gm %. For<br />
urinary tract infections the study cohort included<br />
individuals with a urine culture resulting<br />
in greater than 105 colonies per milliliter.<br />
In order to examine the care for<br />
routine and uncomplicated conditions<br />
only, patients whose charts showed a noninutritional<br />
cause for their anemia, or that<br />
had a chronic urinary tract infection, urinary<br />
tract anomaly or chronic pyelonephritis,<br />
were eliminated from the studY<br />
cohort.<br />
Table 4 illustrates varying patterns of<br />
performance in treatment and follow-up in<br />
three IHS service units. The numbers in<br />
the table are population-based indicators<br />
that express the probability based on emipirical<br />
data that a patient at a given point in<br />
the process of care will pass successfully to<br />
the next. Likewise, the probability that a;
- 131 -<br />
A \ ,,1. XIX, No. 3 PEHFOHRMANCE ASSESS. iE.' l<br />
con"sumer %will pass successfully through<br />
multiple successive elemnents of care can<br />
be obtained directly from the number of<br />
individuals in the study cohort who suc-<br />
.essfully completed the sequence, but also<br />
can be calculated as the product of the intervening<br />
probabilities."a Thus the<br />
"continuity-of-process index" of Table 4<br />
expresses the probability that a paitient<br />
screened positive (in this case for either<br />
anemia or a urinary tract infection) will<br />
achieve contact with the system, have the<br />
problem recognized, receive tre' Rnent,<br />
make contact for follow-up, have the need<br />
for followv-up recognized, and receíive the<br />
followv-up servnice. As shown in Table 4,<br />
this probability ranges ftomr 0.55 in Service<br />
Unit C to 0.09 in Service Unit E. The<br />
aggregated results suggest that the three<br />
Sc'rvice Units have three distinct pattems<br />
of care. Service Unit C, with a continuityof-process<br />
index of 0.55 for treatmnent and<br />
follow-up, appears to have no particular<br />
step in the process of care which stands out<br />
as a relative deficiency. Service Unit D,vwith<br />
a continuity-of-process index of 0.36,<br />
is similar to Service Unit C except for recognition<br />
(indicators 2 and 5), which appears<br />
as the relative impediment. Service<br />
Unit E, with a continuity-of-process index<br />
of only 0.09, appears to have substantial<br />
deficiencies in both contact (indicators 1<br />
and 4) and recognition (indicators 2 and 5).<br />
The next step in the analysis would be to<br />
determine if these distinctions continue<br />
1when the results are disaggregated and<br />
examined by1<br />
tracer.<br />
" Care must be taken in multiplying together PU's<br />
olt.iii< .d fromn different tracer conditions and different<br />
cohorts, because patients recciving adequatet cwrt<br />
early in the process of care may not be independent of<br />
those receiving adequate care later on. Specifically,<br />
patients receiving adequate care at one stage may also<br />
he more likely to receive adequate care at another. In<br />
fact, such nonindependence is illustrated in the data<br />
reported by Novick,'° although it was not explicily<br />
pointed out by him. We have avoided this problem by<br />
calculating continuity-of-process scores only for functicns<br />
or sequences offiunctions where we were able to<br />
ob.serve the passage of the cohort throughout the sequence.<br />
Thus, our continuity-of-process scores are<br />
observed, not calculated. When greater knowledge is<br />
obttaiued about the interdependence of functions we<br />
may be able to combine continuity-of-process scores<br />
ohbtained from different cohorts.<br />
The assessment method can also<br />
examine the distribution of care among<br />
various types of consumers, with one ofthe<br />
most useful distinctions being consumers<br />
at different risk to particular health problems.<br />
In a study of prenatal care at one IHS<br />
service unit, 22 of 50 pregnant women in<br />
the study cohort were classified as high risk<br />
becaus(e they were under the age of 18<br />
years, over the age of 35 years, primigravida,<br />
with parity equal to or greater than<br />
5, or with a history of miscarriage or spontaneous<br />
abortion, while the other 28<br />
women were classified as average risk.<br />
Table 5 shows results for three indicators<br />
(of the 25 employed in the study) which<br />
constitute a simple se(luence to examine<br />
the continuity of process of gonorrhea<br />
screening. Respectively, the indicators<br />
examine the proportion of women achiesing<br />
contact itl the systemni by the 20th<br />
gestational week, the proportion of those<br />
with pregñiancy recognized by the 20th<br />
week, and the proportion of those having a<br />
= cervical culture by the 20th gestational<br />
week.<br />
As is apparent from the indicator results<br />
and continuity-of-process index of Table 5,<br />
system performance favors the average risk<br />
group at each step of the process. The reasons<br />
for the disparity are suggested by the<br />
encounter-based indicators for pregnancy<br />
recognition and gonorrhea screening disaggregated<br />
by site of contact as shown in<br />
Table 6. Unlike population-based indicators,<br />
encounter-based indicators are<br />
computed in units of patient encounters<br />
with the system. Thus, only 43 per cent of<br />
encounters by high-risk patients compared<br />
with 67 per cent of encounters by averagerisk<br />
patients due for recognition of pregnancy<br />
resulted in pregnancy recognition.<br />
Similarly, only 33 per cent of encounters<br />
by high-risk patients compared with 71 per<br />
cent of encounters by average-risk patients<br />
with pregnancy recognized and due for<br />
gonorrhea screening received a cervical<br />
culture. When disaggregated by site of contact,<br />
the results suggest that the prenatal<br />
clinic performs well in both the recognition<br />
and screening function, the public
NUTTING ET AL.<br />
TABLE 4. Results From Three Service Units of the Indicator Sequence<br />
Designed to Examine the Continuity of Process for Treatment and Follow-Up<br />
1. Contact for The proportiotn of patients with<br />
evaluation a positive screening result who<br />
made contact with the health<br />
cate system within an<br />
appropriate time frame<br />
(within 3 weeks for anemia and<br />
within 2 weeks for urinary<br />
tract infection).<br />
2. Recognition of The proportion of patients making<br />
problem contact for whom there was any<br />
evidence that the problem<br />
was recognized.<br />
3. Provision of The proportion of patients with<br />
treatment the problem recognized who<br />
received appropriate treatment<br />
within 2 weeks afer<br />
recognition.<br />
4. Contact for The proportion of patients<br />
follow-up achieving contact with the health<br />
care system within a<br />
time frame appropriate<br />
for follow-up (within 3-6 weeks<br />
afier treatment initiated for<br />
anemia and %w ! in 4 weeks aftcr<br />
~t..i;.~.q.~; :."i.s;Ne or-omp}eretefor<br />
unnary dtra'cC iiiLi.~c2i/,.<br />
5. Recognition of The proportion of patients making<br />
need for contact for whom there is any *<br />
follow-up evidence that the problem<br />
andlor the need for follow-up<br />
was recognized.<br />
6. Provision of The proportion of patients with<br />
follow-up recognition of problem<br />
and/or the need for follow-up,<br />
who received an appropriate<br />
follow.up (hemotocrit, hemoglobin,<br />
or reticulocyte count for anemia;<br />
urine culture or microscopic<br />
urinalysis for urinary<br />
tract infection).<br />
Continuity-of- The proportion of patients with<br />
process index a positive screening result who<br />
completed the entire health<br />
care sequence. (The continuityof-process<br />
index may also be<br />
computed as the product of the<br />
proportions for each of the<br />
indicators 1 through 6).<br />
Service Service Service<br />
Unit C Unit D Unit E<br />
0.92 (62/67) 0.93 (931100) 0.73 (73/100)<br />
0.90 (56;62) 0.76(71,93) 0.62 (45173)<br />
0.95 (53/56) 0.,99 (70/7, ) 0,93 (42/45)<br />
0.83 (441/53) 0.89 (62/70) 0.52 (22/42)<br />
0.69 (39'44) 0.61 ,i,. .6',<br />
'.<br />
0.95 (37/39) 0.95(36/38) 1.0 (9;9)<br />
0.55 (37/67) 0.36 (36/100) 0.09 (9/100)<br />
The results shown are an aggregate ofdata derived from nutritional anemia and urinarytractinfections.The study<br />
cohorts for Service Units D and E are random samples of 50 patients foreach tracer. The study cohorts from Senive<br />
Unit C consist of a total sample of 36 patients with anemia and 31 patients with urinarv tract infection.<br />
health nurses performn well in recognition,<br />
but the hospital outpatient department and<br />
the field clinics contribute substantially<br />
less to the perfornnance.<br />
- 132 - .MEDICAL CARE<br />
The data in Table 6 show that the<br />
average-risk women who were due for ca;re<br />
made a higher proportion of their encouln<br />
ters with the prenatal clinic than did the
V Xl. IX, No. 3<br />
- 133 -<br />
PERFORMANCE ASSESS.MENT<br />
TABLE 5. Results From> a Stervirt, Unit Showing Population-Based Indicators<br />
for Prenatal Care<br />
Total Cohort High Risk Average Risk<br />
(n - 50) (N' - 22) (N - 28)<br />
Contact The proportion of pregnant women who 0.64 (32150) 0.54 (12122) 0.71 (20!2/)<br />
made contact with the health care systemr<br />
by the 20th week of gestation.<br />
1H¢-c ignitionn Thl proportion of pregnant uomen making 0.69 (22/32) 0.50 (6112) 0.80 (16;20)<br />
contact who laJad tIeir pregnaiUncy rtcosgnized<br />
by the 20th week of gestation.<br />
Screening The proportion of pregnant women with 0.82 (18/22) 0.50 (3/6) 0.94 (15'16)<br />
pregnancy recognized uho had a cervical<br />
culture by the 20th week of gestation.<br />
Continuity-of- The proportion of pregnant women who 0.36 (18,'50) 0.14 (3/22) 0.54 (15:28)<br />
process index had a cervical culture<br />
by the O20th week of gestation.<br />
A patient asi considered high risk if she was less than 18 years ofage, over 35 years of age, primigra'ida, had<br />
parit. equal to or greater than 5, or liad a histuor) of miscarriage or spontaneous abortion.<br />
high-risk woomen. Specifically, for<br />
average-risk women 42 per cent (10 of 24)<br />
of all encounters when due for recognition<br />
were with the prenatal clinic and 67 per<br />
cent (14 of 21) of all encounters when due<br />
for screening were with the prenatal clinic,<br />
while for high-risk women only 7 per cent<br />
(1 of 14) and 33 per cent (3 of 9) of all<br />
encounters when due for recognition and<br />
screening, respectively, were with the<br />
prenatal clinic. Consequently, the superior<br />
perforrnance of the prenatal clinic favors<br />
the average-risk group by virtue of the different<br />
utilization pattems of the two risk<br />
groups. A similar pattern at another Service<br />
Unit has been studied in detail and is<br />
reported elsewhere. 2 '<br />
The above examples illustrate how the<br />
assessment method operates, and how it<br />
can point to areas where there are de-<br />
TABLE 6. Results for Encounter-Based Indicators of Pregnancy Recognition<br />
and Screening for Gonorrhea, Disaggregated by System Component<br />
High Risk Average Risk<br />
Cohort Total Patients Patients<br />
Recognition rate: The proportion of<br />
visits by) the 20th w eek of gestation<br />
by patients not prev iously<br />
recognized as pregnant, in which<br />
recognition of pregnancy oc-urred.<br />
Hospital outpatient department 0.35 (6/17) 0.25 (218) 0.44 (4/9)<br />
Prenatal clinic 1.00(11/11) 1.00 (1/11) 1.00(10/10)<br />
Field clinic 0.00 (015) 0.00 (012) 0.00 (013)<br />
Home visit by public health nurse 1.00 (5/5) 1.00 (3/3) 1.00 (212)<br />
Total visits 0.58 (22/38) 0.43 (6/14) 0.67 (16/24)<br />
Screening rate: The proportion of<br />
visits by the 20th week of gestation<br />
by patients with pregnancy<br />
recognized and due for a cervical<br />
culture, in which a cervical culture<br />
was taken.<br />
HIospital outpatient department 0.11 (1/9) 0.00 (013) 0.17 (1/6)<br />
Prenatal clinic 1.00 (17/17) 1.00 (3/3) 1.00 (14114)<br />
Field clinic 0.00 (0/11) 0.00(1) - (0)<br />
Home visits by public health nurse 0.00 (013) 0.00 (012) 0.00 (0/1)<br />
Total visits 0.60 (18/30) 0.33 (3/9) 0.71 (15)21)
NUTTING ET AL.<br />
- 134 -<br />
ficiencies. The anecdotal data presented<br />
on corrective actions suggests that in some<br />
cases the method may enhance the assurance<br />
tfunction, although we do not yet Ihave<br />
systematic evidence.<br />
Discussion<br />
Requirements for a method to assess the<br />
quality of care in Indian Health Service<br />
service units were defined. A method was<br />
developed to try to fulfill these requirements<br />
and was applied in 25 health systems<br />
to test whether the requirements had<br />
been met. Some of the requirements were<br />
fulfilled while others were not.<br />
The first requirement calls for examining<br />
the performance of the entire health<br />
system and is based on the assumption that<br />
the performance of the total health system<br />
cannot be inferred from the performance of<br />
individual components, which is especially<br />
important in Indian Health Service,<br />
where consumers are often scattered geographically<br />
and highly mobile. Rather thia<br />
being limited to specific facilities or provider<br />
groups, the assessment begins with a<br />
sample of the community with specific<br />
needs for health service and tracks them<br />
through their encounters with all system<br />
components, including components that<br />
do not necessarily view themselves as part<br />
of the system, thus fulfilling the<br />
requirement.<br />
The second requirement calls for the<br />
examination of care for all members of the<br />
community, not just patients, and for differentiation<br />
among subgroups. By selecting<br />
study cohorts from the entire known<br />
community ofconsumers, as demonstrated<br />
in the immunization and prenatal care<br />
tracers, and using original source documents,<br />
as demonstrated in the anemia and<br />
urinary tract infection tracers, the second<br />
requirement is largely met. However,<br />
more work must be done to determine the<br />
extent to which the entire com-nunity of<br />
consumers has been identified in [HS service<br />
units.<br />
MEDICAL CARE<br />
The distribution of care by risk group<br />
was successfully examined, with the finding<br />
that two materna! and child health<br />
clinies provide d better care to avsrage-rinsk<br />
mothers than to high-risk mothers because<br />
ofdifferent utilization patterns. Although it<br />
appears that the method could also<br />
examine the distribution of care across<br />
other subgroups of the population, this has<br />
not yet been demonstrated. *o<br />
The assessment focuses on the performance<br />
of a broad range of functions, including<br />
especially those most important for<br />
ambulatory care, rather than on particular<br />
health conditions, as called for in the third<br />
requirement. However, the usefulness of<br />
the resulting information depends on the<br />
assumption that the care received for the<br />
tracers is representative of all care. The<br />
original application of this method found<br />
that the functions had similar relative performances<br />
for all the tracers used,' which<br />
was supportive of this assumption. More<br />
recent applications of the method also<br />
found similar pattems for most tracers, but<br />
with some notable exceptions, for example<br />
the high recognition rate for suture<br />
follow-up care compared with much lower<br />
recognition rates in follow-up care for other<br />
tracers. Such variation across tracers indicates<br />
that a'thorough investigation is<br />
needed on whether and how to aggregate<br />
across tracers. For example, classes of tracers<br />
might be found that have similar patterns<br />
of care within classes but different<br />
patterns across classes. Although current<br />
aggregates are possibly useful starting<br />
points, they are not based on sound<br />
theoretical or empirical foundations and<br />
therefore should be accompained by the<br />
tracer-specific results.<br />
*o In concept, any attribute of medical care can be<br />
distríbuted across different subgroups of the p opulation.<br />
The distribution of accessibility" and<br />
utilization" across various types of population sibgroups<br />
has been widely studied, but the process of<br />
care as we have defined it has not. Shortell hbis<br />
attempted a more precise definition of distrhibution of<br />
cwae by applying concepts of ecoinolics.
- 135 -<br />
The fourth requirement is largely met in<br />
that the assessment method traces the care<br />
received throughout an episode and relates<br />
it temporally to health status. However,<br />
causal linkages between process and<br />
health status are not established by the assessment<br />
and so outcome of care is not<br />
established. The number of health conditions<br />
available to use as tracers is expanded<br />
greatly by examliiiting only segments of the<br />
process of care rather than the entire process<br />
for every tracer, although this limits the<br />
conclusions that can be drawn about the<br />
continuity of the entire procer. jf care because<br />
the functions are not independent of<br />
one another. More work is needed to understand<br />
clearly how changes in one function<br />
influence the performance of others.<br />
The fifth requirement established<br />
criteria for the selection of tracers. These<br />
criteria have been met with the exception<br />
that the representativeness ofithe tracers as<br />
a group has not been demonstrated, as<br />
noted above.<br />
The sixth requirement establishes<br />
criteria for defining standards of care for'"<br />
the tracers. The standards established<br />
were both minimal and agreed upon by the<br />
local practitioners. The work of Brook 24<br />
suggests that because the assessment<br />
method uses explicit standards for the<br />
process of care rather than implicit judgments<br />
or indicators of outcome, the absolute<br />
performances will be relatively low.<br />
However, this is not important so long as<br />
the performance indicators are consistent<br />
over time and across comnponents, functions<br />
and consumer groups and their statistical<br />
attributes are not relatively worse than<br />
methods using implicit judgments or outcome<br />
indicators. More investigation of<br />
these assumptions is needed.<br />
Although the assessment method identifies<br />
areas of major deficiencies, it has not<br />
demonstrated that it systematically identifies<br />
remedial deficiencies, as called for in<br />
the seventh requirement. In order to determine<br />
if the deficiencies uncovered are<br />
able to be corrected, the assessment must<br />
be imbedded in an effective assurance<br />
process. Alternative possible remedies<br />
must be identified and evaluated and then<br />
implemented successfully. This is the<br />
point where other assessment methods<br />
have encountered the most difficulty, and<br />
it is widely recognized that assessments<br />
have not reliably led to improvements in<br />
quality.' 3 . 16.S4.25<br />
The eighth requirement deals with cost.<br />
Our experience indicates that the cust of<br />
employing this method in IHS service<br />
units is modest. Nonprofessionals were<br />
used successfully to collect and tabulate<br />
data from the nonstandardized health records<br />
currently found in Indian Health Service.<br />
In 10 service units it took 13 data<br />
collectors and two supervisors a total of 291<br />
working days to identiiy the cohorts and<br />
abstract data from the health records, plus<br />
another 69 working days to tabulate the<br />
data. Thus an average of 36 nonprofessional<br />
days was required to collect and<br />
tabulate the data per service unit. Each<br />
worker also spent eight days in training.<br />
On the average, data were abstracted from<br />
3.4 different health records for each consumer,<br />
with study cohorts of approximately<br />
50 consumers for each of nine tracers. This<br />
produces an average time for data collection<br />
and tabulation of 38.4 minutes per<br />
episode of care studied and 11.3 minutes<br />
per record abstracted.<br />
Others have also reported on the cost of<br />
data collection by nonprofessionals for<br />
episodes of care using explicit standards.<br />
Some agree with our experience that the<br />
cost is modest7 ' ' 0 while others have found<br />
it expensive."'16 Recent work by Albrecht<br />
and Kessner :t suggests that while the cost<br />
of abstracting may be modest, the' fixed<br />
1 Although not reflected in the above cost estimate,<br />
IHS is implementing a computerized health<br />
information system which integrates data from all the<br />
health records maintained for a given consumer. Once<br />
in operation, this system should significantly increase<br />
the efficiency of the assessment through its use of<br />
standardized encounter forms, a well-defined list of<br />
consumers from which to draw cohorts, and identification<br />
of the location of all relevent records.
Vol. XIX, No. 3<br />
costs for operating such an assessment<br />
method may be high.<br />
Thisi ,s's ti'.tit milethod is t t oflbw .s<br />
a replacement tor other methods currently<br />
available that provide an in-depth examination<br />
of specific system components.<br />
Rather, it is offered as a broad-brush assessment<br />
which provides a mechanism for<br />
detecting problems in system performance<br />
which may then be examined in more detail<br />
using the other methods. Use of this<br />
approach in a variety of health care settings<br />
has proved to be feasible and has uncovered<br />
areas ofdeficiency in total system performance.<br />
WVork on improving and applying<br />
the method continues by Indian Health<br />
Service, with particular effort being given<br />
to testing the reliability of its measurenents,<br />
examining how to select more<br />
representative sets of tracers, and in imbedding<br />
it in an assurance process that improves<br />
the quality of care.<br />
Acknowledgment<br />
The authors wish to expresstheir gratitude to Robert<br />
H. Brook, !M.D., for his many helpful comments and<br />
encouragement, and to Louise Burbank. Claudina<br />
Noriega and Sandra J. Woolbright fior their diligent<br />
efforts in the preparation of the manuscript.<br />
References<br />
- 136 -<br />
1. Carison R. The end ofmedicine. New York: John<br />
Wiley and Sons, 1975.<br />
2. Illich 1. Mledical nemesis: the expropriation of<br />
health. London: Calder and Bayars,. 1975.<br />
3. Navarro V. The underdevelopment of health of<br />
working America: causes, consequences. and possible<br />
solutions. Am J Public Health 1976;66:538.<br />
4. Fuchs V. Who shall live? New York: Basic Books,<br />
1974.<br />
5. Moss CE. Illness, immunity. and social interaction.<br />
New York: John Wiley and Sons, 1973.<br />
6. Lawrence PR, Lorsch JW. Differentiation and<br />
integration in complex organizations. Administrative<br />
Science Quarterly 1967;12:1.<br />
7. Shorr GI, Nutting PA. A population-based assessment<br />
of the continuity of ambulatory care. Med<br />
Care 1977;15:455.<br />
8. Kessner D l. Kalk CE, Singer J. Assessing<br />
health quality-the case for tracers, N Engl J .Med<br />
1973;288(i): 189.<br />
9. K!essner DMt. Kalk CE. Contrats in health status.<br />
Vol 2: a strategy fir evaiiuting health services.<br />
PERFORH.ANCE ASSESS.SMENT<br />
Washington, D.C.: National Academy of Sciences,<br />
1973.<br />
10. N'ovick LF. Dickinson K.Asnes R, May Lan SP.<br />
Lowsenlsteinl R. .Assessinc'it .faml atior s-are: application<br />
of the tracer methodology. !Med Care 1976; 14:1.<br />
11. Nobrega FT, 'lorrow GW Jr, Smoldt RKC Offord<br />
KP. Quality assessment in hypertension: analysis of<br />
process and outcome methods. N Engl J Med<br />
1977;296: 145.<br />
12. Gonnella JS, Daniel ZL, McCord JJ. The staging<br />
concept-an approach to the assessment of outcome<br />
of ambulatory care. Mled Care 1976;14:13.<br />
13. Hirschhorn NH. Lamstein 1, Klein SF,<br />
McCormnack J, Warner TN. Quality by objectives: a<br />
model of quality of care assessment and assurance for<br />
ambulatory health centers. Journal of Ambulatory<br />
Care Management 1978;L:55.<br />
14. Howell JR. Osterweis M.. Huntley RR. Curing<br />
and caring-a proposed method fur selifassessment in<br />
primary care organizations. J Communíty Health<br />
1976; 1:256.<br />
15. Shortell SM. Continuity of medical care: conceptualization<br />
and measurement. Med Care<br />
1976; 14:377.<br />
16. Donabedian A. Needed research in the assessment<br />
and monitoring of the quality of medical care.<br />
Washington, D.C.: Department of Health Education<br />
and Welfare, 1978 (DHEW publication no. PHS-78-<br />
3219.)<br />
17. Beck MH, Drachman RH. Kirscht JP. A field<br />
experiment to evaluate various outcomes of continuity<br />
of physician care. Am J Public Health 1974;64:1062.<br />
18. Starfield BH, Simborg DW, Hom SD, Yourtee<br />
SA. Continuity and coordination in primary care: their<br />
achievement and utility. Med Care 1976;14:625.<br />
19. Breslau N, Rceb RC. Continuity of care in a<br />
university-based practice. J Med Educ 1975;50:965.<br />
20. Steinwachs DM. Measuring provider continuity<br />
in ambulatory care: an assessment of alternative<br />
approaches. Mled Care 1979;17:551.<br />
21. Nutting PA, Barrick JE, Logue SC. The impact<br />
of a maternal and child health care program on the<br />
.quality of prenatal care: an analysis by risk group. J<br />
Community Health 1979;4:267.<br />
22,. Aday L, Anderson R. Development ofindices of<br />
access to medical care. Ann Arbor: Health Administration<br />
Press. 1975.<br />
23. Anderson R. Health service use: national trends<br />
.and variations. Washington, D.C.: DCpartment of<br />
Health Education and Welfare, 1972.<br />
24. Brook RH. Quality of care assessment: a comparison<br />
of five methods of peer review. Washington,<br />
D.C.: National Center for Health Services Research<br />
and Development, 1973. (Publication no. HRA 74-<br />
3100.)<br />
25. Williamson JW. Assessing and improving<br />
health care outcomes. Cambridge, Mass.: Ballinger<br />
Publishing Company, 1978.<br />
26. Morehead MA. Ambulatory care re íiew: a neglected<br />
priority, Bull NY Acad Med 1976,52:60.<br />
27. Albrecht JA, Kessner DM. Assessing ambulatory<br />
care: a coml)arittie anal>-sis of tiiree<br />
methodologies. (Unpublihed iéemno.)
- 137 -<br />
Systems and Procedures of Patients<br />
and Intormation Flow<br />
Arnold Reisman, Fh.D., Joao Mello da Silva, Ph.D., and Jloseph<br />
B. Mantell, Ph.D.<br />
THE TASK of properly scheduling an annual load of several<br />
hundred thousand patient visits to more than 100 doctors in 28<br />
different departments, and supporting these visits with timely,<br />
accurate, and complete flows of information is very cominplex.<br />
This task is further complicated by the fact that patients generally<br />
require timely sequencing of laboratory tests, X-rays, and<br />
consultative appoitments. From 1968 to 1973 in the clinic of one<br />
large health center, thc number of patient visits per year increased<br />
approximately 26% (Figure I) and the institution's physical<br />
plant was greatly expanded, tying up much of the administrative<br />
talent and resources. More importantly, however, the staff<br />
capability had become more diversified. It had disproportionately<br />
increased in number to serve the rapidlyexpanding<br />
inpatient population and to perform additional research<br />
and teaching activities. The systems and procedures for<br />
scheduling and processing the patients through the outpatient<br />
clinic degraded to the consternation of patients, doctors, and<br />
administrators alike.<br />
The objective of this study was to investigate the systems and<br />
procedures for outpatient flow and to recommend improvements.<br />
rhe specific objectives were to:<br />
1. Understand and describe, in operationally meaningful<br />
terms, outpatient flow systems and procedures in effect at<br />
the time of the study;<br />
HOSPITAL & HEALTH SERVICES ADMINISTRATION 1 WINTER 1978
Figure I. Total Patiet Visits<br />
125<br />
12n<br />
115<br />
l1n<br />
1 5 10<br />
ln5<br />
1in<br />
- 138 -<br />
1968 1969 1970 1971 1972 1973<br />
THE PATIENT VISITS IN 1968 ARE USEO AS THE BASE FIGURE ('100)
- 139 -<br />
2. ldentify problemn areas in a -, and all patient flow related<br />
operations;<br />
3. Collect and analyze meaningful hard data to test various<br />
hypotheses regarding the status of the patient flow systems<br />
and procedures and the reasons for the evolution of these<br />
systems to their current state;<br />
4. Delineate the most meaningful and reasonable goals and<br />
objectives for the patient flow system;<br />
5. Recommend both long-range and short-range improvements<br />
to the patient flow related operations.<br />
Historical background<br />
The "old appointment system" was romprised of a central appointment<br />
desk (CAD) and several parrially decentralized nonuniform<br />
procedures. Within the Medical Division, the CAD<br />
scheduled physical examinations only. All types of appointments<br />
of the surgical division as well as "forme'r" appointments for all<br />
departments were made either by the desk receptionists or by the<br />
medical secretaries. Routing Section personnel were responsible<br />
for consults, X-rays, laboratory tests, special exams, and reports.<br />
Each doctor kept an appointment sheet specifying the time of day<br />
during which different types of patients should be scheduled.<br />
Because of the rapid growth of the outpatient clinic and a lack<br />
of adequate support, the CAD became less effective in performing<br />
its job. As matters worsened, complaints abcut patient flow<br />
were expressed by physicians throughout the clinic. The major<br />
criticisms were incompetence in the scheduling function and<br />
favoritism (more patients were directed to certain physicians or<br />
departments than to others.) Consequently, some departments<br />
transferred control of their appointments (except reports and<br />
consults which were kept by the Routing Section) to appointment<br />
secretaries stationed on the department floors. Further movement<br />
toward decentralization followed. As each department devised<br />
its own rules for scheduling patients, a gradual degeneration<br />
of the clinic's overall systems and procedures for making<br />
appointments resulted. This degeneration was further aggravated<br />
by the rapid turnover of clerical personnel which was<br />
HOSPITAL & iHEALTH SERVICES ArtMINISTRA1ION 1 WINTER 1978
- 140 -<br />
spurred on by conflicting directives, lack of systematic. training<br />
and enforcement, and a system which was difficult to master or<br />
comprehend. Figure II depicts the dynamic feedback process<br />
which led to the degradation of systems and procedures.<br />
Productivity of the clerical staff, measured in terms of patient<br />
visitslclerical position ratio, is shown in Figure III. The ratio<br />
dropped sharply for the appointment-making personnel. In contrast,<br />
the ratio for the other clerical staff categories remained<br />
fairly constant. It is interesting to note that while thc "actual"<br />
system effectiveness was dropping, the perceived effectiveness,<br />
as seen by the physicians, had discontinued its downward trend<br />
and appeared to be improving because of the ability of physicians<br />
to exercise more control over clerical staff as the clinic'E<br />
systems became more decentralized.<br />
A study of the problem was made in early 1972 by a Subcommittee<br />
on Registration and Routing which generated a report.<br />
Another attempt to study the problem was made in late<br />
1973, with the establishment of a Patient Flow Committee. In<br />
January, 1974, this committee established the task force which<br />
was led by the authors of this paper.<br />
Method of study<br />
The aim of this study was to report on the systein description<br />
of the clinic and to provide a set of recommendations. It was<br />
recognized that these were preliminary recommendations and<br />
that more detailed investigation of the problem areas identified<br />
by this study should be undertaken. Specifically, it was felt that<br />
subsequent studies should repeat the activities of this study,<br />
utilize mathematical models, and develop an implementation<br />
scheme (Figure IV).<br />
As shown in Figure IV, this study phase was devoted to learning,<br />
describing and analyzing the clinic as a system. As part of<br />
this phase, a graphical description was obtained by flow chartfng<br />
the various patient flow related processes. Also, hard data were<br />
collected to test various hypotheses which emerged from discussions<br />
with members of the clinic's medical, administrative,<br />
and clerical staffs on patient flow related operations. Future work
c<br />
1<br />
'-a<br />
- 142 -<br />
Figure III. Patient Visits/Clerical Staff Ratio<br />
3.000<br />
900<br />
700 1 AVE. GR. TO AL<br />
° 6nn \ # RECEP.<br />
500 \<br />
c- 400 7o1<br />
í<br />
x 11<br />
200<br />
800<br />
AVVE. T AVE.. .OTA L<br />
700<br />
2.000<br />
900 .<br />
- ~ AVE. GR. TOTAL<br />
Da- 1 # ROUTING ROUTI &'"P.R. P .7R. . x 3<br />
PERSONNEL<br />
fr n%<br />
69 70 71 72 . 73 74<br />
YEAR<br />
.
u.<br />
o<br />
a.-<br />
1<br />
W.<br />
LZi<br />
- 143 -<br />
c c S<br />
C.<br />
C 1<br />
o k<br />
re<br />
I9
- 144 -<br />
should be devoted to the development, testing, and evaluation of<br />
each of the preliminary recommendations through mathematical<br />
analysis andlor computer simulation.<br />
Patient, appointment and physician classification<br />
The patients at the clinic are classified into three categories:<br />
"new," "new-old," and "trmer." A new patient is one that is<br />
coming to the clinic for the first time. In most medical departments,<br />
a former patient is one who has been at that de-partment<br />
previously and has had a complete physical examination<br />
within a reasonable t.l:e A "new-old" patient is orne who, regardless<br />
of having been at that ¿»partment previously, has not<br />
had a complete physical examiner. ion recently. This length of<br />
time varies from one to two years depending on the department.<br />
Some medical and surgical departments do not require physical<br />
examinations. In these departments, a former patient is one who<br />
has been at that department within a specified length of time,<br />
while a new-old patient is one who is coming to that departmert<br />
for the first time or returning after the specified length of time.<br />
Patient appointments are classified into five categories: new,<br />
new-old, former, consult or referral, and report. A consult is necessary<br />
when the patient's doctor feels that the patient should be<br />
seen by specialists or subspecialists. Normallv this takes place ini<br />
another department. A report is an appoinUiient (which may or<br />
may not involve an examination) during which the doctor informs<br />
the patient of test results and diagnoses.<br />
Some of the clinic trainees, called "fellows," are allowed to<br />
perform work-ups of patients for the staff doctors in certain departments.<br />
Depending on the department, the fellows either<br />
form a pool and work up patients for any staff doctor or each one<br />
works up patients for only one staff doctor.<br />
Senior fellows may be given the privilege of assuming patient<br />
responsibility under siaff supervision. The number of appointments<br />
available by a department depends, therefore, not only on<br />
the staff's available time to see patients but also on the number of<br />
fellows assigned to the department and on the functions they are<br />
allowed to perform.
- 145 -<br />
Thc cu rrent appointmren t- niakinig system<br />
In ger .,al, there are two basic appointment-making systems.<br />
One is the centralized system, in which all appointments for all<br />
departments are made in one location. The other is the decentralized<br />
system. in which all the appointments of each department<br />
are made by a secretary or equivalent personnel<br />
stationed on the department floor. Every request regarding appointments<br />
is directed tu . central area for the centralized system<br />
and to the corresponding secretary of a department for the decentralized<br />
system. All other appointment systems are variants<br />
andlor combinations of these two basic systems. Both systems<br />
have distinct advantages.<br />
In the centralized system, since there is only one location responsible<br />
for all the scheduling:<br />
1. Calls for appointments will always be correctly directed or<br />
connected. In cont. ;t, calls to the decentralized system may<br />
be transferred several times before reaching the correct location.<br />
2. Persons making the appointmer.ts know the available times<br />
for all doctors. Function:, such as coordination of multiple<br />
appointment.s, and modifications of appointment schedules<br />
to keep up with the demands of the various appointment<br />
types can therefore be efficiently performed.<br />
3. Patients will have only one appointment card. In the case of<br />
a multiple áppointment, paper work will be kept to a<br />
minimum and the Record Room will receive only one request<br />
for the patient's chart.<br />
4. Economy of scale may result.<br />
In the decentralized system, since each department has its own<br />
appointment-making person(s):<br />
1. Appointments are made for but a few doctors in a single<br />
specialty. Thus it is easier for the person to know the doctors'<br />
characteristics (e.g., preferences for certain cases and<br />
50 HOSPITAL & HEALTH SERVICES ADMINISTRATION I WINTER 1978
- 146 -<br />
the lengths of time usually required for the varicus appointment<br />
types) than it is for an appointment secretary in a<br />
central location vbc^ must know the characteristics of all<br />
clinic doctors.<br />
2. The leaming period is shorter and so replacement personnel<br />
are more easily trained.<br />
3. Follow-up appointments are made at the floor just after the<br />
examinations.<br />
4. The doctors can easily check their schedules for<br />
availabilities and patient load and any changes in schedule<br />
can be easily communicated to the appointment secretary.<br />
The clinic studied had a combined centralized-decentralized<br />
system. The centralization was characterized by the work of the<br />
Routing Section. This section made most of the consult and report<br />
appointments, and scheduled special exams, e.g.: EKG,<br />
EEG, basal metabolic rate test. The decentralization .was characterized<br />
by the fact that the other appointment types (and also<br />
some reports and consults) were ¡nade in the departments by<br />
several clerical people. A study was conducted to determine who<br />
was scheduling patients for each department.<br />
Five types of appointment-making personnel were identified:<br />
appointment secretaries, receptionists, medical secretaries, Routing<br />
Department personnel, and personnel from the Appointment<br />
Service Desk. l For nearly all departments, different types of personnel<br />
were responsible for different appointment types and different<br />
appointment-making procedures were being used. :n general,<br />
the study clearly sho4 d the lack of uniformity of systems<br />
and procedures throughout the clinic.<br />
Current appointment practices<br />
Upon making an. appointrnent, a patient is assigned to a doctor<br />
or for a special exam in a specific department at a specified time.<br />
Appointment systems may be classified into three categories:<br />
pure block, individual, or mixed block-individual.<br />
'The Appointment Service Desk makes some of the new and new-old appointments. Its<br />
main function is to screen calis which have not specified a doctor or a department.<br />
REISMAN, DA SILVA, MANTELL 1 Systems
- 147 -<br />
A pure block appointment system assigns the same appointment<br />
:ine ..t the beginning of the clinic session to all patients. An<br />
individual system assigns a different appointment time to each<br />
one of the patients. A mixed block-individual assigns a group Ujt<br />
patients to certair. times (generally at the beginning of a clinic<br />
session), but also assigns individual appointment times to each<br />
one of the other patients.<br />
At the time of the stuJv only one department of the clinic used<br />
the pure block system. The individual appointment system was<br />
used by rriost doctors; the mixed block-individual appointment<br />
system was used by the others.<br />
There are two basic types of prescheduling. In "prior prescheduling"<br />
the patient is scheduled for certain laboratory tests,<br />
X-rays andlor special exams before an appointment with the primary<br />
doctor. In "posterior pre-scheduling," tenative appointment<br />
times are saved for the patient, in addition to the patient's<br />
primary doctor appointment. After the primary examniinat;oií, the<br />
doctor decides whether the tentative appointments should be<br />
used or cancelled. Combinations of the two types of prescheduling<br />
can and have been used. There are advantages and<br />
disadvantages to butis kinds of prescheduling.<br />
One advantage of prior pFc.ciheduling is that the primary doctor<br />
will have laboratory, X-ray and special studies results available<br />
at the time of the appointment. This may help in the initial<br />
examination. Another advantage is that when no further tests<br />
andlor consults are necessary for the patient, the doctor may be<br />
able to give a full diagnosis at the initial appointment. One disadvantage<br />
is that the patient may sometimes take unnecessary<br />
tests. Another is that as a result of the doctor's examination, the<br />
patient may be required to return to the laboratory 2 or to the<br />
Radiology Department.<br />
The advantage of posterior prescheduling is that the time span<br />
for the complete routing may be less than the time span which<br />
could be obtained on the day of the appointmnent. One of the<br />
disadvantages is that when the doctor decides to cancel some of<br />
the prescheduled appointments, these appointments may go un-<br />
'In s¢-ne cases. it nmay be possible to eliminate this inconvenwieince to the patiúLnt by<br />
.aving specimens and blood -aimples for a certain period of time in the lab.<br />
HOSPITAL & HEALTH SERVICES ADMINISTRATION 1 WINTER 1978
- 148 -<br />
filled due to the short lead-time of the cancellation. In addition,<br />
the advantage of this type of prescheduling may be negated<br />
when the doctor finds it necessary to order additional tests and/or<br />
consults.<br />
At the time the study was conducted, neither kind of prescheduling<br />
was extensively used at the clinic.<br />
Systems-related problenms<br />
Long lead-times for initial appointments were of great concem<br />
to the clinic as well as to the patients. If their appointment is too<br />
far into the fucure, patients may look for medical care elsewhere.<br />
Consequently, appointment times are not used because such patients<br />
often do not cancel (they become no-shows on the day of<br />
the appointment) or they cancel too late for the clinic to react and<br />
fill the appointment slot.<br />
A two-week appointment distribution study 3 was run to determine<br />
the number of no-shows (including unfilled cancellations)<br />
and appointments, botl-, unfilled and kept, for the different<br />
appointment types for each department. The study revealed that<br />
a significant percentage of appointment times, especially those<br />
reserved for consult and report appointments, were going unfilled<br />
in many departments. Also revealed was the fact that noshows<br />
are a significant problem for the clinic. For the clinic as a<br />
whole the percentage of no-shows for new, new/old, and forrnie;<br />
appointments was more than 12%.<br />
Proper balancing of patient appointment types on the physicians'<br />
day sheets was a problem. This can be seen quite vividly<br />
by examining the results of the appointment distribution study<br />
mentioned above and comparing these with the results of<br />
another study which examined the appointment availabilities for<br />
new, new-old, and consult appointment types, as they were one<br />
week after the beginning of the project. In this study it was found<br />
that in some departments the next available new, new-old, or<br />
consult appointment was often as long as one to two months into<br />
'Only patients who actually made appointments were considered. 1 hose who did not<br />
make appointments due to the long lead-time or any other reason were not considered.<br />
REISMAN, DA SILVA, MANTELL 1 Systems
- 149 -<br />
ihe future. It was discovered that in some departments certain<br />
appointment times, e.g., reports, were unfilled while at the same<br />
tii... the demands for new, newlold and consult times exceeded<br />
their availability.<br />
Figures V and VI identify the problems:<br />
1. The number of ways that a patient can be tr:..sferred before<br />
making an appointment or cancellation.<br />
2. Patients wishii.; to make cancellations may not reach the<br />
correct locations. Consequently, if a patient has multiplc<br />
appointments, some appointment times will remain reserved,<br />
even though the patient has contacted the clinic to<br />
cancel them. 4<br />
Both problems resulted because the various types of appointments<br />
are made in many different locations and, iri general, the<br />
persons making appointments (and cancellations) do not know<br />
exactly who make 'ihe various types of appointments for other<br />
departments.<br />
Especially for the out-of-town patients, the time span of routing<br />
should be kept as short as possible. s The major obstacles to a<br />
short time spa.. are the difficulty in obtaining consults, time<br />
availability constraints (i.e., certain tests are only available at<br />
certain tines of the day), and procedural constraints (i.e., some<br />
tests which require special preparation may not be followcd by<br />
certain other tests.)<br />
It was found that missing or incomplete charts were a major<br />
problem for many people in the clinic. A missing or incomplete<br />
chart may cause delay in the patient examination, a deay ;in the<br />
report, and often results in a great loss of tC ie i-i locating the<br />
missing material.<br />
When an appointment is made, the person who makes it<br />
should generate an appointment slip and send a copy to the chart<br />
processing area. This is called preregistration. If a patient is not<br />
preregistered, the paper work is started when the patient arrives<br />
'A patient with multiple appointments may assume that if he cancels one of the appointments,<br />
the remaining ones are also cancelled. Usually this is not true.<br />
sit was the clinic's policy to try to schedule out-of-town patients for the shortest possible<br />
routing time span.<br />
HOSPITAL & HEALTH SERVICES ADMINISTRATION 1 WINTER 1978
a o<br />
0<br />
44<br />
u<br />
LI<br />
Xr> a<br />
i,<br />
LU<br />
u-<br />
:1<br />
- 150 -<br />
I 4<br />
1<br />
1
- 151 -
- 152 -<br />
at the clinic. As a consequence, the patient may be late for the<br />
appointment or may be missing necessary paper work.<br />
In the case of multiple appointments, it is possible for the<br />
patient to be preregAs.:.zd more than once. This occurs when all<br />
the appointments are not made by the same person. As a result,<br />
there is duplication of paper work, the chart may not be sent to<br />
thc place of the first appoi -.ment (it will be sent to the first place<br />
requesting it), and if the patient decides to cancel, appointment<br />
times are usually lost (Figures V and VI).<br />
Physical examinations are usually scheduled early for both<br />
morning and afternoon clinic sessions, mostly for the morning.<br />
Often routing, Ilboratory tests, and X-rays are required after<br />
these examinations. Since a physical, on the average, takes one to<br />
two hours, the bulk of the physicals are finished after 10 a.m. and<br />
before noon. As a consequence, bottleneck situations develop in<br />
routing, laboratory, and radiology between 10 a.m. and 1:30 p.m.<br />
A smaller bottleneck occurs around 3 p.m. as a result of tne conmpletion<br />
of the early afternoon physicals. Figure Vil shows these<br />
peak-load situations at thc laboratory. The situation is worsened<br />
by the fact that the heaviest patier;t load occurs during the lunch<br />
hours when these three areas (routing, radiology and laboratory)<br />
are often short of personnel.<br />
Room availability is another source of problems. These problems<br />
tend to be more noticeable in the medical departments,<br />
especially those performing complete physical examinations.<br />
This is less of a problem for the surgical division because surgeons,<br />
in general, spend more time in the hospital tha ' the medical<br />
division physicians. As a result of room constraints both the<br />
physician and the patient may be required to wait for a vacant<br />
examination room.<br />
A study of this problem was conducted. In recognition of the<br />
difference in needs for roóms between medical and surgical divisions,<br />
the data on the examination room availability were separated<br />
by division. The number of examination rooms in a department<br />
was compared with the number of staff physicians on<br />
duty. It was apparent from this study that some departments had<br />
more than enough rooms while others had too few.<br />
Physicians' schedules also have an impact on the problem. For<br />
REISMAN, DA SILVA, MANTELL I Systems
- 153 -<br />
Figui.'¢ VII. Patient Arrival Distribution for Blood Drawing in<br />
Laboratory-Day of WeeklTime of Day<br />
60,1<br />
55<br />
50<br />
45 e *<br />
·<br />
40<br />
THURS .-. :<br />
I \<br />
30 35 o .. . \<br />
MON.<br />
'Ji ';.<br />
,~~~~~~~~~~~~er<br />
· e~. ·WED.<br />
1 S d>\ ¡ \<br />
15 I<br />
FRI.<br />
in<br />
5<br />
1
- 154 -<br />
example, a physician may schedule two physicals at 8 a.m. These<br />
patients will be worked up by fellows while the staff doctor may<br />
be seeing former patients. In th,.s .ituation, the staff physician's<br />
patients will be using three or more examination rooms at the<br />
same time. As was seen in the study, few departments can afford<br />
this many examination rooms for each staff physician.<br />
Personnel-related problems<br />
Obviously, the clinic's patient flow system is very complex. For<br />
the entire existing system to work properly, it was necessary for<br />
the many patient flow related processes to interact smoothly.<br />
Thus, it was imperative that all personnel understand how their<br />
work affected not only their particular process but also all the<br />
others with which it interacts. At the time of the study, there<br />
were no structured training prograr;is in which the new employees<br />
were given an overall perspective of their job as it related<br />
to other clinic operations. The only training which took place was<br />
on-the-job because a. new employee was hired only when the<br />
position was already vacant. Therefore, adequate training was<br />
very difficult because of the urgency with which the employee<br />
was needed. Poor job performance and lack of coordination resulted<br />
since a new employee did not know how his or her work<br />
interacted with the other employees' functions.<br />
In some areas there were certain inequities in job classitications.<br />
Some jobs, where specific skills were a definite requirement<br />
(such as typing), were classified on the same level as jobs<br />
requiring no specific skills, no ratient contact, and no machinery<br />
to operate. This was due, in part, to incorrect original classifications<br />
but more often it was the result of lack of reclassification as<br />
job duties changed and became more complex. There was no<br />
procedure apparent for regular updating of job descriptions and<br />
classifications. The job classification inequity seriously delayed<br />
recruitment of qualified personnel. To compensate for this problem<br />
supervisors and department heads juggled personnel within<br />
their departments to insure efficient operation. They, at times,<br />
had to shift employees from one classification to another without<br />
changing salary or job classification. This often resulted in per-
- 155 -<br />
sonnel working in positions outside their classitication and in<br />
dissension among employees if variations in salary scales became<br />
known.<br />
Depending on the department, the work-load varied conriderably<br />
for the same job classification. For example, an appointment<br />
secretary of a department attending many patients had a<br />
heavier work load than one stationed in a department attending<br />
fewer patients.<br />
A lack of upward mobility in the job often resulted iii lack of<br />
interest and motivation to perform well since there was no incentive<br />
or additional compensation for doing so. There were only<br />
two job levels for medical secretaries; medical secretary and<br />
senior medical secretary. Appointment secretariec had but one<br />
job category and no opportunity for advancement.<br />
Conflicting directives caused personnel prob!errs. In many instances,<br />
clerical personnel ::ceived instructions from physicians<br />
as well as from a supervisor. Sometimes these instnlctions conflicted<br />
with one anether and it therefore became difficult for the<br />
supervisors to enforce those systems and procedures which<br />
should be uniform throughout the clinic. This situation presented<br />
a dilemma for clerical personnel and resulted in a decline<br />
of morale.<br />
Rapid p.rsonnel turnover further aggravated the problems.<br />
This lack of training resulted in poor job pertormance and criticism<br />
from both physicians and supervisors (sometimes conflicting<br />
directives), which in turn resulted in low morale. Low morale<br />
causes personnel turnover. As one can see, the situation was a<br />
vicious circle in which turnover led to more turnover, to further<br />
degeneration of systems and procedures, which led to staff dissatisfaction,<br />
etc.<br />
Ultimate objectives<br />
The objectives reflect a synthesis of hard data and subjective<br />
inputs from medical, administrative and clerical staff regarding<br />
existing and desired operations. They are to:<br />
1. Tailor make to the needs, wishes and constraints of every
- 156 -<br />
doctor, the best possible methods of scheduling.<br />
2. Effectively, quickly and uniformly process all<br />
appointment-making functions, e.g., making, cancelling,<br />
and rescheduling appointments, in a manner which is consistent<br />
with good medical care, and with human and material<br />
resource constraints in mind.<br />
3. Give each patient the advantages of a lárge group practice,<br />
e.g., laboratory and radiology facilities, in-house expert<br />
consultative capabilities, attached hospital facilities, etc.<br />
4. Effectively triage patients.<br />
5. Enable each doctor and/or department to pretest any and all<br />
changes of scheduling procedures.<br />
6. Effectively requisition, deliver in a timely fashion, and<br />
control patient-related information flow, e.g., charts, X-ray<br />
and laboratory reports, and f.htancial information.<br />
7. Balance patient flow to avoid overloading clinic units.<br />
8. Have a patient flow system which can easily adapt to<br />
changes.<br />
9. Have available, in an easily accessible and updated form,<br />
all relevant data regarding patient flow, e.g., appointment<br />
availabilities.<br />
10. Keep both the patient waiting time and physician idle time<br />
low.<br />
11. Make appointments available in a manner which is consistent<br />
with the patient's needs.<br />
12. Efficiently handle multiple appointments and the time<br />
span necessary to complete a multi-apFointment diagnostic<br />
andlor treatment plan.<br />
13. Reduce the number of no-shows and of unfilled time slots.<br />
14. Provide for flexibility ,a doctor's schedules within a reasonable<br />
planning horizon so that changes in availability<br />
times and policies can be made easily.<br />
15. Have the advantages of both centralized and decentralized<br />
scheduling systems.<br />
16. Make available to physicians innovative means of scheduling<br />
patients and an ability to pretest such in a "laboratory"<br />
environment, e.g., prior and posterior prescheduling.
- 157 -<br />
17. Keep the time span of the patient routing as short as possible.<br />
18. Improve receivables handling, e.g., reaucing number of<br />
lost billings.<br />
19. Identify all -:.itient flow associated administrative costs to<br />
design a system which will optimize the same.<br />
20. Improve personnel morale and cffectiveness.<br />
21. Improve hiring practices.<br />
22. Have the administrative support necessary to implement<br />
the clinic's patient flow objectives.<br />
Personnel related recommendations<br />
1. Using inputs from this project, a patient flow procedures<br />
manual should be generated and kept elrrent.<br />
2. A systematic training of existing clerical staff in systems<br />
and procedures should be established. This trainirng<br />
should consist of lecture sessions on the various patient<br />
flow processes. r;fis could be done with the help of the<br />
process diagrams discussed. The essence of each job (goals<br />
and objectives as well as systems and procedures) and its<br />
role in the clinic operations must be discussed in detail<br />
with the employees performing the job.<br />
3. A systematic training of new medical and clerical personnel<br />
in systems and procedures should also be established.<br />
4. A systematic enforcement of systems and procedures is<br />
imperative.<br />
5. An improvement in hiring practices is necessary. This can<br />
be done by proper testing procedures and by maintaining<br />
a small pool of trained personnel to move into both temporary<br />
and permanent vacancies.<br />
6. A reclassification of jobs, allowing more upward mobility,<br />
should be made. For the same job positions in different<br />
departments with different work loads, some kind of incentive<br />
should be established.<br />
7. Commendations from doctors, when work is done properly,<br />
st. ild be encouraged and would help the morale of<br />
clerical personnel.<br />
HOSPITAL & HEALTH SERVICES ADMINISTRATION I WINTER 1978
- 158 -<br />
8. Consider relieving medical secretaries of appointmentmaking<br />
duties, where feasible.<br />
9. Define more clea.J'y lines of responsibility and control of<br />
clerical staff to avoid conflicting directives.<br />
Scheduling-related recommendLa'ions<br />
1. Consider providing, at .ach heavy consultative load desk,<br />
scheduled "standby" time on a rotating basis, to take up<br />
urgent consults without overloading any one doctor. This<br />
could be accomplished by having at least one physician at<br />
all times performing some clinic functiorns which could be<br />
easily interrupted.<br />
2. Based on historical data, consider devising a battery of lab<br />
andlor X-ray studies which result from some percentage<br />
(say 80% or 90%) of physicals for a given doctor or department.<br />
3. At the doctor's discretion, consider prescheduling the<br />
above lab and/or X ray studies prior to the patient's appointment<br />
for a physical with sufficient lead-time to allow<br />
for processing, reporting and delivery of results to the doctor.<br />
6<br />
4. When historical data indicates that certain appointment<br />
types with a given doctor, inevitably or to a large extent,<br />
are followed by some other appointment, either with the<br />
same doctor or elsewhere in the clinic, then consider prescheduling<br />
the latter as well.<br />
5. Consider storage of specimens for some prescribed period<br />
of time in the laboratory. The inconveniences caused by<br />
additional visits to the laboratory will be avoided. This<br />
would be especially useful for prescheduled patients.<br />
6. Consider a patient standby list. The patients in this list<br />
should be easily reached and would help to alleviate the<br />
problem of no-show and late cancellation appointment<br />
slots going unfilled.<br />
'As a first attempt to identify which further appointments result from physical appointmnents.<br />
studies were run in each department to determine how many of each type of<br />
consult, X-ray tests, laboratory tests, and special studies were ordered over two-week<br />
periods. The results of these studies are displayed in Table 1.<br />
REISMAN, DA SILVA, MANTELL 1 Systems
- 159 -<br />
TABLE I: Pnmary DesklConsultant Desk InputlOutput<br />
UROLOCI<br />
I[<br />
1 1 1<br />
1 1<br />
1 1<br />
* . . .<br />
. .<br />
E<br />
I I 1<br />
. . #. .<br />
. .<br />
. .<br />
:S
- 16u -<br />
7. Consider overbooking policies based on no-show and late<br />
cancellation statistics, by department or by physician.<br />
8. Consider calling patients to ascertain arrival. By doing<br />
this, many of the predictable no-shows could be determined.<br />
Personnel requirements for performing this job<br />
need to be considered.<br />
9. Consider altemative scheduling methods to optimize patient<br />
waiting time and physician idle time. The following<br />
factors are among those which should be considered:<br />
staff-fellow interaction, room constraint, patient load, and<br />
appointment sheet time increments. Computer Simulation<br />
can be used to pretest the efficacy of various altematives.<br />
10. Consider altering the availability of each appointment<br />
type, based or both physician determined criteria and patient<br />
needs. Patient needs can be determined to a certain<br />
extent by examining appointment availability data and<br />
data on unfilled appointments.<br />
11. Study room availability constraints and the effect of same<br />
on doctors' schedules, fellows' schedules, staff-fellow<br />
interaction, and hospital rounds. Again, Computer Simulation<br />
is a good study vehicle.<br />
12. Define a patient priority classification schc ne, based on<br />
patient's urgency and importance, and doctor's professional<br />
interest. Institute this classification scheme<br />
where feasible and acceptable to the individual's practice.<br />
13. Consider providing booking options which will have, for<br />
example, 100% filled appoilntment sheets for the most immediate<br />
time periou, 80% filled for the next time period,<br />
60% filled .. , etc. Such a booking procedure will allow<br />
more urgent patients (as determined by the patient priority<br />
scheme, described above in 12) to be scheduled sooner and<br />
without overloading the doctors.<br />
14. Define the optimal time periods for the above, for each<br />
desk or each doctor and each appointment type. As an<br />
example, a department could have new appointment times<br />
fully booked for a two week period while the consult times<br />
could be obtained on the day of the request.
.Recomme;tded systenz<br />
- 161 -<br />
.;any of the clinic's problems, identified earlier, are concemed<br />
with information flow. Problems arise when information is not<br />
readily available or is not transmitted properly.<br />
In respon - ' to, these problems, a patient flow information data<br />
bank was recommended. This information bank should contain<br />
all information relevant to the patient flow processes and should<br />
be easily and quickl;- ,~cessible. This information would include<br />
appointment availabilities for all doctors and central file of<br />
scheduled appointments. In addition to receiving, the data bank<br />
would be responsible for distribution of all information regarding<br />
patient flow, such as billing, scheduled appointments, and<br />
demographic information.<br />
In the recommended system all doctors' appoir.tments would<br />
be made at the departments, with the exception of consults, reports,<br />
and special exams which would be held by the routing<br />
area. This is, in fact, what was presently being done at the clinic.<br />
After an appointment is made, all informatloiU, regarding it<br />
should be sent to an appointment processing area. This area<br />
would be responsible for all paperwork associated with appointments<br />
and updating ¡i¡e central file of appointments as well<br />
as appointment availabilit es. Further, by checking the central<br />
file of scheduled appointments, this area would easily locate appointments,<br />
make cancellations, catch duplicate appoin¿n.^nts,<br />
and coordinate multiple appointments, multiple cancellations,<br />
and rescheduling.<br />
In the recommended system, appointment information would<br />
be updated both at the departments and in the appointment processing<br />
area. When a doctor or a department is not specified, the<br />
call will be directed to the Appointment Service Desk where a<br />
triage is made. Some patient triage situations are too corrplex to<br />
be properly handled by a person with non-medical training. In<br />
response to this problem, a Physician Triage Officer should be<br />
established. It could possibly be implemented by providing<br />
physicians' consultative services (on a rotating basis) to handle<br />
these triaging of non-routine patients. With such a service available,<br />
a non-medical - orson who does triaging of patients would<br />
HOSPITAL & HEALTH SERVICES ADMINISTRATION 1 WINTER 1978
- 162 -<br />
have the opportunity to conr:',: a physician about difficult situations.<br />
For both routine and non-routine triaging situations, a questionnaire<br />
could be developed to be completed by the patient,<br />
which would provide a means for systematic evaluation of triaging<br />
accuracy. On the ba;-s of this questionnaire, an appointment<br />
could be changed at the discretion of the Physician Triage Officer<br />
or any other medical staff.<br />
For multiple appointments, the appointment processing area<br />
will make a triage (with the help of the Physician Triage Officer<br />
when necessary). Then the area will call the proper deE!;z and<br />
coordinate the appointments. This coordination will be made<br />
easily becau,e all appointment availabilities will be known at the<br />
appointment processing area. In tl.e new system, the problem of<br />
excessive transferring of calls fromr department to departrnent<br />
will be avoided.<br />
A major problem for the clinic was that of no-shows. 7 However,<br />
many of these no-shows are predictable. For example, a<br />
patient with multiple appointments may call his primary department<br />
to say that he will not be able to make this appointment.<br />
The primary department appointment will be cancelled;<br />
however, often the person making the cancellation does not<br />
know about the other appointments for that day. These appointments<br />
will not be cancelled and will result in no-shows. This<br />
situation can bei avoided in the recommended system since,<br />
whenever a patient cancels an appointment, all other appointments<br />
can easily be checked in the scheduled appointment file.<br />
Part of the updating procedure in the appointment processing<br />
area could be to check in this file (urnder the patient's name) for<br />
additional appointments for the same day or associated, in some<br />
way, with the cancelled appointmentS.<br />
A predictable no-show can also occur when . a patient with an<br />
appointment scheduled sometime in the future has an appointment<br />
with the same doctor at an earlier date. This often happens<br />
due to a change in medical urgency for the patient. In the present<br />
'The billings foregone due to patient no-shows are estimated to be in the $1,000,000 to<br />
$2.000,000 range per year.
- 163 -<br />
system, there is nr'. :vstematic procedure for cancelling the original<br />
appointment and often the result is a no-show. This situation<br />
can also be avoided in the recommended system by making it<br />
part of the updating procedure to check for these duplicate appointments.<br />
Another feature of the recommended system is that data collection<br />
for studies such as the ones described in this paper would be<br />
much more easily collected since all patient flow related data<br />
could be collected at one location, i.e., the information data bank.<br />
Thus, such an appointment system would have most of the<br />
advantages of both centralization and decentralization. Further,<br />
it can be easily implemented since no major changes in clinic<br />
operations are necessary.<br />
Strategy of going towPtr: ',¡e ultinate system<br />
There are two ways in which improvements in systems and<br />
procedures c,: be implemented. One is to schedule a complete<br />
changeover on a certain day. The other is to do it gradually,<br />
step-by-step.<br />
The first method would be too risky and too disruptive to the<br />
clinic operations and not readily accepted by the clinic personnel.<br />
On the other hand, gradual improvement will not be so disruptive<br />
and will be more easily implemented. In this implemnentation<br />
scheme, as tangible improvements are realized,<br />
credibility and increased confidence and patience with the system<br />
will result. Consequently, further changes will be more<br />
readily accepted. Figure VIII shows the dynamics of this implementation<br />
process.<br />
As an initial step in the implementation process, a manual<br />
system could be devised to handle appointment-related information.<br />
As soon as an appointment is made, information regarding<br />
appointment availability will be immediately updated at the department<br />
(on the appointment sheet). At the same time, some<br />
mechanism for transferring this information to the appointment<br />
processing area would be initiated. In this manual system, the<br />
means of transferring this information would be by telephone,<br />
lift or runners. Such a manual system would not be disruptive to<br />
present clinic operations.
- 164 -<br />
oo<br />
a,<br />
r.<br />
3<br />
»e<br />
'<br />
i<br />
e,<br />
n(fD<br />
-_.<br />
la
- 165 -<br />
- A major problem with such a system would be the lead-time<br />
for trar.sferring information from the desks to the appointment<br />
processing. During this time, the appointment availability file<br />
will not be up to date. This would cause some inefficiency in the<br />
appointment processing area's ability to reschedule and coordinate<br />
multiple apl, intments.<br />
The ideal situation would be to have the appointment<br />
availability file updated ;tmmediately from the desk. This feature<br />
necessitates some kind oi mcchanized information transmission.<br />
This mechanized transmission could be accomplished by using<br />
teletypewriters or some other telecommunication device at the<br />
desk to transfer information to the appointment processing area.<br />
In addition to the speed with which information would be<br />
transmitted, this system would have the advantage of being able<br />
to generate typewritten copies of the appointment information at<br />
the appointment processing area directly from the desks immediately<br />
after the appointment is made. This capability would<br />
eliminate the need for filling out and sending a pregistration<br />
form, since all the necessary. information could be sent via the<br />
teletype. Further stiidy could be made to determine the feasibility<br />
and desirability _f .e;iding other types of information, such as<br />
requests for charts and X-ray, ~ the same manner to other clinic<br />
areas.<br />
Once a mechanized information transmission device is in operation,<br />
the major system bottleneck would be in the time necessary<br />
to manually update the files. This problem could be solved<br />
by mechanizing the updating procedures using some computer<br />
configuration.<br />
Once the appointment information system is mechanized, the<br />
next step would be to incorporate other patient-related information,<br />
such as billing, which could be accessed easily from the<br />
proper places. Thus, this appointment information system could<br />
be the foundation of a complete communications-based information<br />
system.<br />
An advantage of this implementation scheme is that, at each<br />
step, improvements are made in the patient flow system. Also,<br />
each of these steps ser -s as a transition and learning period for<br />
the next. Further, if, at any step in the implementation scheme,<br />
HOSPITAL & HEALTH SERVICES ADMINISTRATION 1 WINTER 1978
- 166 -<br />
the feasibility and desirability do not justify the implementation<br />
of the next step, all the advantages of the current stage will be<br />
retained. Moreover, with proper forethought and planning, each<br />
of the implementation steps could serve as a backup mode for the<br />
more advanced system sta 's.<br />
It is important to note that the successful implementation of<br />
each step is, to a large extent, dependent on personnel support.<br />
Therefore, improvements in the personnel situation must accompany<br />
any and all changes in systems and procedures.<br />
In future work, detailed study of each of these steps should be<br />
made. Cost-benefit analyses of different means by which each<br />
step could be implemented should be performned. Also, the<br />
scheduling recommendatior.s presented earlier should be extensively<br />
investigated.<br />
More than a year has passed since this study was completed.<br />
The clinic personnel are currently methodically implementing<br />
most if not all of the recommendations delineated, using the<br />
directed step-by-step approach of achieving the ultimate goals<br />
and objectives.
- 167 -<br />
T1c Iteole of Olieraionls Rcscarlch iii<br />
Rcgioulal IIeCilIh Plauniiig,<br />
Larry J. Shlmatgant, llarvey W1olfe<br />
Unive s",, g/ ittlisbrgh, P'ittisbudrgl, P'mJs!lh ni(<br />
It. I)ixois Sjl)'is, Jr.<br />
,imaiJord Ul,.. r,!/, , Slnalford, California<br />
(llec'eived Augist 1, 1972)<br />
Operations-research workers have not met with much success in being accepted<br />
as integral members of regional-health-planning teams, owing in part to a lack<br />
of understanding by health planners of the skills the operations researcher<br />
has to offer and in part the analyst's inability to demonstrate that he can close<br />
the gap between theoretical modeling and the impleulentation of his res-lts.<br />
This paper explores tite growth of regional health planning in the United<br />
States and highlights its important problem areas. The literature of operations-research<br />
applications to health planning is reviewed critically with respect<br />
to thie feasibility of miodels atid the appropriateness of assuinptious.<br />
Specific problems with the types of studies currently in the literature are identified<br />
and recommendations are made for improved coordination between operations-research<br />
workers and health planners.<br />
H 'AI,TII Pl1,ANNEli Iiave! inlriltld ' ,liv(ry sstemn tliat d(,vtlol),)d lini>ost<br />
randomly iii accord withi local politica. economic, and/or parochial interests.<br />
Cammuility3-wide planining typically pl:tyed a minor role. As a result, tlih( untvent<br />
distribution of healit resoaurces :ad s(rvi(ces tirotugalio t a region Ih:.s Ih(4et a per.<br />
tist(eit Irobhlmi coimnlic:ttinig pliininig. F'urlher, aus long as h(iolitals wvr( required<br />
to provide relatively simtple procedures, no great strain vwas placed on nianpow(,r<br />
sul)plies, nor was the ecoeonomi burdent caused by duplicatiozn of servic((s undluly<br />
heavy. Specialization and advanciing technology lhave elihaigd thlis situation.<br />
'T'oday's compl('x medical Iroccedur(es r'luirae X,.l),isiv(,, soplisticite(ld (lUiil)mei't<br />
facilities, as well as teams of higlhly skilled personiíel.<br />
ntl<br />
2IAYslI h1as described the history of health planning in the United States as<br />
highilighted by thr(e lanidmvark é(vSents: Tli( pass:ag( of tite Hill-Burton Ael (1>1. 79-<br />
725) in 194(i; tithe 1Xi joiit publ)lic(atio, by tie, Amnerican Hlosp)ital As.ociationm anud<br />
Ih(, Jublic Ilailtlh Service of tllt report, "Area-wvide lhlalinitig for Isl)pit:is andl<br />
lelated He(alth l Facilities;" tui and th(e pamssage of the Co)mpr-ehensive Ilealth Pllanning<br />
Act of 1966 (J>L 89-749). To th(lies might be added the Regional Medical<br />
Irograni (1>1, S!)-23:i)) eitclted i¡n 1!XiS, ai(d thi(! I',xpeiriillttl l leaultlh Servicets l)e.<br />
liver3y Systems programn adopted iii 1971.<br />
Health planinning int the United States most likely originated with a volulntary<br />
groul) that formed tihe Cinciiimmti Public Healtli Council iin 1917.11 Tihe growth lof<br />
Coinmiunity hicalth couiicils miimlSrooi(cmld; by 1(M99 tih.re ;were 1222 suieih l!o:ld anil<br />
st:te orgtaniz:ttiots. Ma\lanl of thi(s councis served ns the maini htulti-)lt:iiiiiiiLg
- 168 -<br />
Regional Health Planning<br />
bodies for their localities until the early 1960'.ns lin 'area-wíi
- 169 -<br />
Larry J. Shumc- Harvey Wolfe, ond R. Dixon Speas<br />
effeetively availabici< t(
- 170 -<br />
larry J. Shuman, Harvey Wolfe, and R. Dixon Speos<br />
very lcast, a qualitative inprovicni(uit. liucltud('d aiuímong tilhs. a('liVii(i s flir ¡liiihi<br />
planning decisions lhave resilt( d ill shar(irl einiterprises are ma:ternit y sa.¡d (nni rg.n¡cy<br />
care, data processing, inservice e¡du(.ition, labonrtories, a¿¡d híuris ¡ i,.is'.<br />
to forinl a joint veil ure for sl,.. :.g s( rvi)'es ,I i' iiot diflicult to ini)l¢,l1i1(.11,<br />
the obvious logistical probhleis th¡lt resul.<br />
::¡ith, I'r o,:<br />
Iinplheinntation is not so siilps>h, wIin oniie or mlor(,r institutions giví' up i ,a ) .irvi,'í.<br />
(ilir(ely, while s(l('ectld olsil)itllis ¡('1 att:
- 171 -<br />
'- ionoal Heolth Ploanning<br />
be vicvwed as a planning model, yet the(y arc disenchanted with the sucee.ss these<br />
models have had with respect to implenmentation.<br />
Twao in-hosl)ital studies that utilized somie ,f ti(h operations.resear(.lc techliilues<br />
iinow being applied to regional-l)lapu ing problenms are by WoLFE V 5iJ aid I"ETTEII ANI)<br />
TH~oMPsos.i'i In 1964, Wolfe developPed an inte(ger-prograniming mnodel for allo.<br />
cating nursingservices *within a hospital. An imxportant attribute of Wolfe's model<br />
wvas the adaptationl of psycholne
- 172 -<br />
Larry J. Shuman, Harvey Wolfe, ond R. Dixon Speos<br />
and Thompson to the abstract mod(l postulated by I:lagle. S.IALL00O1D, -0NIK,J,<br />
AND <strong>OF</strong>FENISENDI5 I 1<br />
Ipropose<br />
a-. '; ial simulation niodel thliat describes the patieniit's<br />
movemenit tlirough t he hc:lltlh systeiii, detaIliiig resources required for various stages<br />
of illness and recovery. ''The nod
- 173 -<br />
Regional Health Planning<br />
are propo.~sd in tile Revelle et al., Feldstein, and Iirystynak papers. Thie first twn<br />
are con(erne(d , ith tluh(reulosis a¡n( tihe last w¡ithl rheulmatie fev(er. ieveli. et al.<br />
lirst posthiltited a deseriptive mod(ll of tlul)erculosis el)hilniiolehgy for a ¢hvehloling<br />
lnation i¡t order to evaluate tier eost eftetive)e'ss of various metilods of control.<br />
Tihe des(ril)tive model ean ihe formulated as a linear program. The solution of the<br />
iin¿eaJr-l)ro>gr'i n)iig motl, yieldlM tie miiiiininl-cost metilod for attaining a given<br />
reduittlti-l it ltul rcutilar. c:s.s h ti iitg :1a S.t.i ilic ti t i i;ridl. ol,<br />
FIeldstein proposes a tube(rculo.sis plianiting model for use ini developing eountrie(s.<br />
This model selects thi( set of activities that woulld maximiz(! tio total econonmic<br />
benefit for given resource coistraints. It consilders the interrelations of public-<br />
Ix)lircy I>re('f,
- 174 -<br />
Larry J. Shunmn, Harvey Wolfe, and R. Dixon Speos<br />
ith( patioeit and provid'r costs attrilhutablh<br />
r4gion.<br />
to Ille( locatioi.s of lhospitals witilin a<br />
CSIE.NIlIACK AS\>) C IIEIL .'S. .<br />
t lg<br />
i)rl),s'Sti :a st:ttia.ll L('ea llitlUeiiq'e knowi\l :Is s(('orgranims<br />
for describin g a híosplital srvicce ar,;'a whi(,', n¡atuiradl arri(,rs e.xist. lii nei tlal<br />
applic.timi, tihe ove'rllappiig of hospitail sarvice areas mnake definitig uniiqniues<br />
botilldaíries for: Ii¡:li¡cell:a a<br />
rcígiu r ísxl 14 ni and Morrill i)rtvide :¿noihbhr applroaei tu lb(' Ioeationail analysis of<br />
rcgiozíal hIos¡)ital syst .ils. I']AIilKM.SONPi21 ts.a :1 1irinsl)orl:ti il li mrly served Il aiient groips is w(e11 as poorly Ioeait(l ( ealth f:iiliti ¡s. Th(.y<br />
I)rOlOUe a;1 i4`r(41 ('OMlii)isx MiitIhlI w\\hl¡ici, .is :t liirast (>te¡), Nsiiiiil:l<br />
!IEI.LEVI.aI illi(:Cl('d IluLt th( siímullatlio model was al)le to Irovide a good replic.ation<br />
on t1he (olic: g(o Ihitsl)i;l: sytsltii alnd 0tihal hli gravit.y m(o wtas (I a g as
- 175 -<br />
Regio.,oi Health Planning<br />
wvho wnouii' hoo.ns the prepaid group practice mode of th(e reeviving eare. Utilization<br />
is considered ti funection of travel time as estimated from existilng hospit:ii.uiage<br />
patterns. Constraints are inicluded that ¡pli c mlinimmini ciapaciti(es or euach linic,<br />
limit. tihe nuniber oí clinics, assig il eople to tl¡o neairest eli.ic, and restricrt exxllnditures<br />
to the available Iredget.<br />
ABEUNÁATIY AND IIEI¡u¿HEY'V 1 propose to solve the healtli-facility-loeatln probilen<br />
by uising thei mtoldl idll'eitol I¡eviisly dts.rilwdl. IFouir olbjectivwf rxtietions are<br />
postulated: (1) maixinize. utilization, (2) iniiiiiiiize distance per capita to til( ne:arest<br />
facility, (3) minimize distance ;. , i 't, and (4) minimize the decline in utilization.<br />
Population is divided into census tracts and then suhdivided into socieiononil.<br />
classes. Utilization is a funiction of distance, social chIaU, anid personal preferene.<br />
The Abernatliy/lHerslcey model consilders aill poinits in a region as possilhl sil(. x<br />
rMther titan evaluating pIred(et(erlined I)oltential lcations. A modii(ed s('ar('<br />
algorithm is used to select the locations. lii considering all p)ossible points as locations,<br />
tliere is a p,:s:bilit.3 that sites that are infeasible, e.g., rivers, pIarks, or very<br />
'expensive prol pert!', imy 1ie cvhosen \as Ineati os.<br />
AlnU.i' of 1l(! iSlt:4. (Of 0loch tial iO(,h ls »roo.s'l by g>gr:n)hli(.'rs :by( o operations<br />
researchers have been incorporat(ed hy B]AUMi'i into a simuhltor for evaluating<br />
primary- and anibulatory-care delivery systems. Baum's simulator is general in<br />
ti it. it. cut('si hlcr aniy ronfligurati(ml of h)slíeiltal oIull.tLItinl!t altivities, .sa 1elihi,<br />
clinics, and neiglhborliood healthl ceniters. ln additio¡n to patient, travel tigel to<br />
facilities, thce model treats some behavioral aspects by considering tie prohlability<br />
of facility choice, keeping appointments, and remaining wvithin a particular delivery<br />
system.<br />
Loeatioai-aly::llsisu .iii.' :,, ,'vilv h v:alil:le metll(odl s for evalhlating tle( s):ltial<br />
relations betwecn ai health delivery sys' .. and the conmmunity. lIowever, they<br />
do not consider a complete spcctrum of E vices, nor do thoy treat tihe pioblem of<br />
distributing specific services throughout the health region nor the consequent effects<br />
of rcmoving or ndding servicés. The nmaasures of effTectivoene(ss used in tlhese mIodels<br />
¡Vive been overly simplistic and inadequate. Except for travel costs, minimal consideration<br />
is given to the cost compo¡íents of thc system. Tlihcre have been no invcstigations<br />
of thc economic costs involved in closing units, relocating physicians<br />
and beds, or constructing new facilities, even though in many cases these costs may<br />
dominate patient travel costs.<br />
models is presented by SCOTT.<br />
A compr!lensive review of location/atllocattion<br />
1 i'i<br />
planning is given by Guoss.lim<br />
A critique of locational models applied to health<br />
Thc operations-reseatrch approach has evolved from in-hospital to multihealth<br />
facility applicatioins. Yet, mnany peolle, includimng those actively involvedl inii ialth<br />
operatiois r:secuiare, liave (luestiouitld tIhe valie arid inlpuct of ntost nl udits. J3.th<br />
GuzEi' AND YOUNo 16' 1 have noted that very few, if any, operations-research projccts<br />
have had a profound effecct on the delivery of health care. Gross(""l has pointed out<br />
tihat, vithl few excetlions, healll operatioiw-r(esarchi studies have resulted in<br />
cruditc models that cither have little meaning or are given low priority by health<br />
professionals. He cites the serious lack of mutual respect, understanding, and<br />
communication between physician, medical rtsearcher, and systems analyst as<br />
another rcason for the lack of success in implementing quantitative studies. "Before<br />
healthi planning ¡moves from the rhetoric to tihe acti(on stage, physicians will<br />
h1ave to be conviicel, thlrough (edueatium i¡id timr)ugh diJun.inji 'tion, tha:t plinniiig
- 176 -<br />
isN ort lwIeI i ,... .iul h ha t e cal ti Ihlltiiii-iiig I)ro('(ss is nor(. :lt extrava'gallLt %i h¡il of<br />
academics, intellectuals, andl bir.auerats ) silting in splendid<br />
world."<br />
isolation frounm ith real<br />
,ICLAuo HLIN, 1 ',I l oun the other hand, is not as pessimistic. He notes that in the<br />
health ciiviriinmi it it is extreit*l altraetive to selhct first thie problens thalt artmost<br />
tractable, *laniing legisl:tion sotglht<br />
to >overcIome, aLI ilablility to look beyonxd its own traditiUnal methoids. Only a few<br />
comprehensive-lhealthi-planning agenciecs have lihad the courage or sophistication lo<br />
support meaningful operations-ret¿. .rch activity.<br />
Even so, a great nimany studies have been carried out, and it seems apparent that<br />
much of the failure of these studies to be implemented lies withi those doing tile<br />
quantitative work. 'Thliy llave lOt integrated tlhCiselves iito tlhe plalnning ,: -<br />
tem. They operate as outsiders viewing the planning system o- an abstract structure,<br />
ignoring the fact that it is political, social, and highly dynamic. DEVISEIIII<br />
has noted that a chas !; exists betwcen researclheis and lhcalth planners to the point<br />
that they do not speak the same language. Consetquently, he hUas recommended<br />
that interdisciplinary exclianges take place among concertned parties. Accuding<br />
to DeVise, prescriptive models must be capable of specifying alternative future<br />
plans in the system, predicting the consequences of choosing each alternative, and<br />
v:aluating th( coisexluuences accordilng to ani acelptablc mcasure of planil¡ing goals.<br />
HILLEBOE AND SCHAEPERI2 have stated that, in the health field more than almost<br />
any other area, the professionals have usually asserted that the subject matter<br />
is too technical anud the consumcr too inexpert to play an important role in planning..<br />
Meaningful health planniiiing, they philosophisc, will be controversial if it is to meot<br />
society's needs. Health planners calnnot be content with attempting a better coordination<br />
of the existing system, but will have to changc this system. WVhile it is<br />
true that plannoers have not extensively embraced quantitative approaches, it is also<br />
true thait qiuatitillivelyc.orilted anialysts lhave slot produced anuy utIk tiha is<br />
meaningful in the immediate context of planners' needs.<br />
Operations research has not bocn useful in regional planning because no one has<br />
used the operations-research approach to aid in the kinds of decisions that current<br />
planiners are making. A large portionl of the quantitative work that has been done
- 177 -<br />
Regionao rfeclth Planning<br />
las ignored tite bIalsíe telets of oi(ratio.s resea'rch and hlis degenrated is;, aun<br />
exercise ini matlihena:tieal modeling: the prolleims that have beeni attenipted hayve<br />
iot beena \well formiliulated; tlihe ol)j(tive fum(tioiis l:ave bev(n naively 'osnslrueted<br />
and tll inasure, of etv yiel ulTtl otii tizatios; quanstitative variables are<br />
considered of prime impilortaince, but b(lihavioral variabhles are lleglected; alternat ives<br />
that are politically and socially infeasible are still considered ina the fe.asible set.<br />
The faihltre of pliianners to view operations research as a viable toul is partially<br />
attributable l«o : nisi.silulhrstas:ding of h t.l' inlohgV :aind I)o\w(r of tli(. op(rationisresearch<br />
process. lMde!l building aid thc developing mathematical techniques caninot<br />
be construed as s ynolymnous with operations rosearch. Yet, many people confuse<br />
thew t terns, expectisg model building by itself to lead to implementable solutionis.<br />
This conilusiomi is firthler a('ee(ituat(edl by operationis rwselrehlers whio lirst<br />
conceive a millthenlirial niodel anad t(heni atteiil)t to lit a health-reltt d problem to<br />
it usnder the guise, of an aplplicatiui. Altihough this :echisique quite ofte(n leads to<br />
journal articles, it rarely results i.a impleme,'t ble decisions. The plamner is lcft<br />
with a theoreitical cont ribution that ihe car. .er use nor appreciate, wvhile t1 hi analyst<br />
(lu:alilies his mod(el hIy e'lainúing thlit no di:ta were availd)hle for validatioii.<br />
ill effect, tile Iih:ll-lh-plisiinig problvss tliaLt I:ave been delinied aid soilve-d do nlot resemblie<br />
the problems for which rationual decisions must. be made.<br />
Develop)ing and eoin(el)taiilizisig nmathenimatical nmodels and t(ehniq
- 178 -<br />
Larry J. Shuman, Harvey Wolfe, and R. Dixon Speas<br />
I Fe IMI ENC:ES<br />
1. W J. APIIERNATIIY AXI) J. C. III.:U víI, "A , l:1iu1' A;IOe-ation .Mí(hel ifor I{egnhIaI l lv':lIlJl<br />
BServiecs I>¡anliiiig," Opns. Res. 20, 629-642(1972).<br />
2. A.rilSTiACl' <strong>OF</strong> IOSI'ITAI, A. Ai:MiF:NT TiUis,'l'l) e (' olwrtive hlformation ('eitcr,<br />
'Ihe School otf Public liealtl, IUiverS;ty of .Mi.ltigan, AiI Arlor, MIeihgalln.<br />
;. 8. I1.itXo.N AX.l, II. W\\I.F:, .llrogranuning Approah for Silertiang<br />
au Optimuni Health Progtran (aseC Mix," plpcr presented at the 40th National lMeeting<br />
of thc OPrI.:ATiosls R:S:AR.CII SOCIF:'eIY C.- Arp:ItICA, Analeiml, Califoritia, 1071.<br />
9. II 1). ('ilt:RXi l Ani J. It. SAlihiladelpilia, ]leiiisylvalnia, 1967.<br />
10. R. D. CouonILIs, "Hospital Complex Atnalysis: An Approach to Analysis for llnimliúng a<br />
Nteiropolitash System of ,Serviee Farilities," UInIpllished 1>11.1). I)issertiatii , tniviersity<br />
of<br />
I . 1>. I1):,sJ:', "Aletilods ui(<br />
I(1i95. 9l'eisylvai.ii:m,<br />
( o'idt'elts ot ll In lt(ri.a'ildilinar Regional 1lospital Stumly,<br />
Ilealth Services Res. 3, 166-173 (Fall, 1968).<br />
12, R. EARICe S0ox, "Ti)c Case for D)cccntralizing Cook County Hospital: Sornc ArPllications<br />
of Liniear Optiniization iln loslpital 'lanniing," Hospital Ila:iimlug ('ounceil for<br />
Mletropllitail ('hiago, VWorkiog >liqeml, Vol. II , No. 1, C( icago, ¡llin¡ois, :3 .<br />
13. "Expterimenital lcalth Scrvices l)clivery Systeins: lnformatiola<br />
Services and Mental lHealth Administration, 1972.<br />
for Appiliants," llealthh<br />
14. A1. S. F1ELSTEIx, "Cost lIcefit Analyísis ald lhIltil Plrogramn Pla;ini¡ng iii 1)Deelulinig<br />
Cotintries," palper presIclted at thc Secondl Conferencec t¡n t'le EcoIInmics of l1ealth,<br />
l:altimiore,: Mlaryland, 196i8.<br />
a<br />
15. R. 13. FErrlER AND J. 1). Ttfotm)dp , "iA 1)ecision Model for D)esign and Olxpratioli of a<br />
Progressive Patient Care Hospital," Mledical Care 7, 450-462 (1969).<br />
16. - ANs - , "The Simulatiotl of liospital Systemis," Opns. ReJ. 13, 689-711<br />
(1965).<br />
17. C. D. FLAGLE, "Simulation Tech!niques Appllicablc to Plublic IHealth Admiiiistrationii,"<br />
pailer presented at thc Filst Anntual Conferncee ot Americatl Statistical As..ciation<br />
and Public Health A.ssociationt, PIroceedings oan Simulation il BIusiness aid Public<br />
liealth, New York, 1966.<br />
18. A- A.I> J. 1'. Youxa, "A¡pl)lie:tiioln f O¡p .io Itens ,'elaci und hl¡dustritil Enginmeering<br />
to 1Problems ot liealtih Services, 1Hospitalis and Public Ilealth," J. Indis¡l. 1Eng. 17,<br />
G09-614 (1966).<br />
19. R. H1. GIGLIO, F. C. KAMINSKY, ANS> J. \'A'rrs, "A Mathemnatical/Computer P>lalming<br />
Mlodel for Emergency Medtlical T'raisportationl Systems," pa.Pler preitcnted al tli,.<br />
Conference ot Areawide ('ompireenicsive 1 lealth Carme Pllaleics, Septeinber, 1i969.<br />
20. (;I.ASG
A^CJonoal neonah ronning<br />
21. 1'. F. (inn.i, Souw D(c!r "itran/is of D(tlol,¡rt and Imsple¡menltalion of ltuistl C'are<br />
Technolog!, and So,'e L.:,ss of thc l.S. Erptrienc, I'iiiVctrity of .iaskathliecali,<br />
I{egiru, Canadla, 1971.<br />
22. - , "`Ur.an !ecalth D)isaolerd, Spalial Aiialysis ,id the El.o¡ouiies of Iltaliah Faciity<br />
Location,!'paper presented at the 40th National M. eeting of the OPEmRATIONS RI:PEARCII<br />
SocXmr or A. -alcA, Aiahieiim, California, 1971.<br />
23. R. GuE, "Opcratioiiat Rescarth ¡oi 11clth a;ndl. Hlspiital Aulmimitratiol," ilospital Admtinitration<br />
10, 0-25 (Fall, 1965).<br />
24. 11. HILWLEDOZ ANDU M. 8CHAEPER, "EvalwUation in Commraity Hlealth: Relaiig Results<br />
to Goals,"-Bu/U. New York Acgqdemy of lledicine 41, 140-158 (¡19>.<br />
25. F. ICiINIOiroK, "Oieratiol lRle.warch aiwl Regiomal l Mdir ogra mS," paeinr pre,<br />
iikitled al tibm Naimitit aiaiiing," New Einglaid J. of .ledidic 279, 1314-1318 (19G8).<br />
28. JOINT C:OMuI3TE: oF TIlE AMERICAN HOSPITAL ASSOCIATION ANX PUBLIC lFALTU<br />
SiERVICE, "Areav;, '- >"':iiilag for Hospitals a!td llelated Health Fa:ilitiea," 1'1IS--,<br />
WVahington, D.C., lu61.<br />
29. F. D. KESNX:IIY ANI) M1%. B. WVoob. :., Developmenf of a Simnulaticn .1!.cI l a n Co!i.<br />
itunity Heloh Srcice Sy8lcn, 'Th Hcalth Sealth rvice Syatem--Ieccml:h T'iaOgje latititute,<br />
Vol. 111, 1968.<br />
30. W. L. KMSICK, "P>lalning l>rogramming and Budgeting in IIcalth," Mldicai Ca.-: 5S<br />
201-220 (1967).<br />
31. L. F. In'Twry',4AK, "A Afode(l for the Rlegiolual C'otroil of Rlleunatic IFever," lI:il*'r<br />
presenited at the 38th National Meeting of the OPERATIOXSa IiEtE.iCII SOCILTY <strong>OF</strong><br />
AMERicA, October, 1970.<br />
32. R. 1. LEE AND L. W. JOSES, The Fundamentala of Good .ledical Care, University of<br />
Chicago >res, Chicago, Illinois, 1933.<br />
33. 1. G. Lovs, R. A. MATHIAS, AND G. TRtEoal, "l)yinaic Iilnrniming of lecaltlh Care $ystenms,"<br />
paper presented at thc 37th National Ieecitlg of the OPEatR.TIOXs RlkEaidCiO<br />
OCímy or AMEalAc^, Washington, D.C., April, 1970.<br />
34. J. W. LUBL%, D. L. DROs.Ess, A.X L. G. WrLtE, "Highway Network 3linimul, IPath<br />
Selection Applied to Facility laiiiiiing," Public Health Reporla 80, 771-778 (1035).<br />
35. C. AIMcLuaOLn , "lHcalth Operatiomls Rescarch atl Svystems Analvysi Literature,"<br />
Syslenm atnd lMedical Care, ALsAX SHELIDO, FRAxK B1AKER AXI) CuarrIas MCLAUGILIX<br />
(ede.) MIT Proes, 1Boton, IM-a_~Sciuseutts, 1971.<br />
36. J. J. MAY, "Health Planning: Its Past and Potential," Health Administration Perspective<br />
A5, Center for Health Administrationa Studies, Univercity of Chicago, Chicago,<br />
l¡¡iniois, 1907.<br />
37. R. L. MORRILL AND R. EABICKSO., "Locational Efficiency of Chicago Hospitais: An<br />
Experimental Model," HfIllh Semri~ Res. 4, 128-141 (1969).<br />
38. - N M. DI. KzeLLr, "'lhe Sinulatioln of lluspital Use atad the l'stiutio<br />
of Iocation Efficiency," Geographic A nal. 2, 283-300 (1970).<br />
39. NATIONAL COMMIRION OX COMMUXITT lHEALTH ElRVtCB#, .Aioan-l'lanning Jor Com.<br />
rnuniy IlcailA Secric, PIublic Afíairs I'rems, Wa.,hitgtoni, D.C., 1967.<br />
40. V. NAvARRO AxD R. PARKER, "A Pl>alinllg Model for l>ersomial lealth Serviees," VWorkinmg<br />
Iaper, ]cpartment of Medical Careo ¡aad Iloipitimi, Tlle Jolama; lolt¡kiitm U Livtcrsity,<br />
laltimore, Maryland, 1967.<br />
41. L. D. Poia, "Areawide Comprehenwivc Healtl IPlanning: The Philadelplia Story,"<br />
American J. Public H*Jalh 59, 760-764 (1969).<br />
42. THE Pa~EsDEArT' COMMUIIBS10 O. HelItiI ';..fi- Wl , CASCIER AND TfRtOgiE, "RtelOrt to<br />
f 1
- 180 -<br />
Larry J. Shumon, Horvy.y Wolfe, ond R. Dixon Speos<br />
the lPresident-A National Program to Conquer lleart Disease, Cancer and Stroke,"<br />
Feblruary, 1965.<br />
43. PuILIC IIh:.ALTII IF}:EIL.TIOX <strong>OF</strong> TllR CISCIXXATI Alt:A, 40th Annual nReport 1957,<br />
Cinciinati: The Fclieration, 1957.<br />
44. L. S. RElE ^N) 1i. IIOLLINSGSoWOTI, "IIOw MIany General llos.pital Beds are Needed?<br />
A lReappraisal of lesd Nee(ds ii Relationshipo to l opulatioi ," 1>11S-309, 1!I:\W, 195.3.<br />
45. C. RtV:VtLL:, F. FF:l,>MA. , AXs ) W. LYN.N, "An Optimuization lModel of Tuberculosis<br />
IEl'didi,¡iioloiy," Ml< 'iuu'únt &c1:i., ApIlilietion .,'.ri.es, 16, 11-190.11211 (1969).<br />
46. - ANs<br />
(1970).<br />
t. SWAIN, "Central FIacility location," G'ograplhical Anal. 2, 30-12<br />
47. R. SASULY ASD 1>. WAnD, "Two Approaches to llealthi<br />
Progmnalie," Medical Care 7, 235-241 (1969).<br />
Planning, The Ideal vs. the-<br />
48. J. ScisiX:i)ita, "A New Approach to I>l:uning thie Growti of a Metrolpolitanl lospital<br />
System," Regional Scienec Refearch Institute, l>hiladelpilia, IPe>i'sylvallin, lC;5.<br />
49. , "Aleasuring the Locatioial Efliciency of the Urban f-lospil ,!," lilrcli<br />
Srenvie Res. 2, i'4-169 (1967).<br />
50. A. J. ScoTr, "LOCawnll-AIOleatio,, Systems: A Review," Gcographical Anal. 2, 95-<br />
119 ¡1970).<br />
51. SEIoW\ICK COUNTY IIEALTli FACILITITS 1>LANh.,:.C COUSNCil SURV:V AND IR:COMMEXI¡iArioxs,<br />
Sedgvwick Couatmy llealth Facility Planning Couincil; Kaimswas lealth Facilities<br />
Informatioi Serviee, PIublication No. 494, Topcka, IKansas.<br />
52. L. J. SIIUMAN, '"athemaltiWal Models for Ilealtlh MIanpow>er ilamning," Department<br />
53.<br />
of Op'rationis Research, The Johlis llopkins University, Ballimiore, Maryland, 196)9.<br />
-- , J. P. Youso, AND E. NADnOR, "A Planning MIodel for Regional lHealth Services,"<br />
lIcalth S~ncea Res. 6, 103-119 (1971).<br />
54. - , C. P. IIARDWICK, ASD G. HUBER, "A Miodel for the Allocation of Ambulatory<br />
lealtlh C-are Centers in a Afctropolitan Area," Icallth Scices Ruc. 8, 121-13S (1973).<br />
55. S. SumvEItTS, "linlluences of Arncawidc Pilaming," l/ospitalo 44, 63-65 (1970).<br />
56. R. D. SJUALLwooo, E. J. SOSDIX, AND F. L. <strong>OF</strong>ExSS xin, "Towards Rn intcg-atcd<br />
57. -<br />
Methodology for the Analysis of Health Care Systems," Opns. Res. 19, 1300 1322<br />
(1971).<br />
, "A Quantitative Appronach to Analyzing Regional licalth Care Systems,"<br />
paper presented at 39th National Mleeting of the OP0RATIOxS RESsEAnCII SOCIETY <strong>OF</strong><br />
,AmeRicA, Dallas, Texas, 1971.<br />
58. J. D. SSYDER AND lM. J. ENRIOHT, "Federal Aid," Hospital '.:anagemcn 102, 37-56<br />
(1966).<br />
59. A. R. SoaEins, "Hospitais Costs and lPayment: Suggestíonsi<br />
Balance," Medical Care 7, 348-360 (1969).<br />
for Stabilizing the Uneasy<br />
60. D. II. STIaiso. AND R. H. STIMsoN, "Operations Research and Systems Analysis in<br />
61<br />
Hlospital Administration," Chicago: Hospital Research and Educational Trust, 1972.<br />
C. ToiIEGAS, R. SWAIN, AND C. ,REVELLE, "Thie Location of Emergency Service Facilities,"<br />
Opns. Res. 19, 1363-1373 (1971).<br />
62. G. WV. TOIR^xACE, W. 11. THoMAS, AND 1). L. SACT-rr, "A Generalized Cost-Effective-<br />
:ness Model for Evaluation of Health Programs," paper presented at 39th National<br />
Meetingi of tile OPERATIOXS RF.8,ACH SocIrTY Or AUr.RICA, Dallas, Texas, 1971.<br />
63. J. vo.N NEUMANN ANO O. MOICEoS.rF:tSN, 'I'lUorg of Ga|es<br />
Princeton University Press, Princeton, 1947.<br />
und EcoCnomic chdaniior,<br />
64. J. 1P. Youso, "No Easy Solutions," GEonGE K. Caiícso (cd.), "The Recognition of<br />
Systems in Health Services," paper presented at the 36th National ;Mecting of the<br />
OPErIATIOXS RI:S:EARCII SOCI:'TY Or ALERICA, ArlingtoIn, Virgi;i;a, 1969.<br />
65. H1. I\OLFE, "A MultilolC Assignment Model for Stafling thie Nuraing Units," Dcpartment<br />
of Oeratiois Rllescarch, Johus llopkins University, Baltimore, Marylanid, 1964.
- .,1 -<br />
Programming, Budgeting, and Control<br />
in Health Care Organizations:<br />
The State of the Art<br />
RPc, rt A. Vraciu<br />
The planning, budgeting. and controlling processes (PBCP) largely subsume all of the<br />
planning and controlling activities of an organization. This paperdiscusses these activities<br />
within the context of a single management control system, focusing on three topics.<br />
First, a brief historical perspective of management concerns which relate to PBCP is presented<br />
and several important external pressures currently imposed on the health care<br />
industry are discussed. Second, normative models of the processes-progri'mming, budgeting,<br />
and controlling-are presented. The discussion focuses on the elements and relationships<br />
of these processes, and numerous references to the literature are provided. Third,<br />
several issues related to the gap between the state of the art in PBCP for hospitals and the<br />
current state of practice are discussed.<br />
Much of the management control<br />
process involves informal communication<br />
and interactions. lni,. .uí<br />
communication occurs by means<br />
of memoranda, meetings, conversations,<br />
and even by such signals'as<br />
facial expressions. Although<br />
these informal activities are of<br />
great importance, ... most companies<br />
also have a formal management<br />
control system. [1, p. 191<br />
I OGaamoNG, budgeting, and controlling<br />
processes (PBCP) represent<br />
the three major phases of such a formal<br />
management control system. A simple<br />
schematic diagram (Figure 1) illustrates<br />
the relationships between these activities<br />
as they occur in a regular cycle and<br />
the role of strategic planning as a<br />
starting point.<br />
"Programming is the process of deciding<br />
on the programs that the company<br />
will undertake and the appropri-<br />
ate amount of resources that are to be<br />
allocated to each program" [2, p. 670].<br />
' is aspec! of the planning process<br />
lcludes the formulaticn ,f corporate<br />
objectives and strategies based on marketing,<br />
legal, regulatory, and social concerms,<br />
as well as on the organization's<br />
own perception of its role. During this<br />
stage, health care organizations would<br />
identify the types of medical services to<br />
be provided, the types of teaching and<br />
research activities to be conducted, the<br />
service populations to be served, and<br />
the general mode of operations for both<br />
a long-run and a short-run planning<br />
horizon.<br />
The second phase is the budgeting<br />
process which expresses the programming<br />
decisions in monetary terms, and<br />
covers a specific time period, generally<br />
one year. The budget represents the<br />
best plan for allocating resources to<br />
achieve the objectives and implement<br />
Address communications and requests for reprints to Robert A. Vraciu. Assistant Professor,<br />
Program in Hospital Administration, School of Public Health, University of Michigan,<br />
Ann Arbor, MI 48109.<br />
0017-9124/79/1402-0126/$2.50/0
- 182 -<br />
Programing, Budgeting, and Control<br />
ii i i i i i · i i~~~~~~~<br />
Figure 1:<br />
Management Control Process*<br />
*Adepted from R.N. Anthony and J.S. Reece, 12, p. 670).<br />
the programs approved in the programming<br />
phase. The agreed-upon budget is<br />
often considered a bilateral commitment<br />
in which responsibility center<br />
managers commit themselves to produce<br />
the planned outpuf with the<br />
agreed-upon amount of resources, and<br />
their superiors commit themselves to a<br />
definition of satisfactory performance<br />
[3, p. 31).<br />
. The tbhird phase of the management<br />
control process represents a feedback<br />
mechanism in which plans and expectations<br />
for subsequent years can be<br />
modified based on experience from<br />
previous years. The prcess involves<br />
the reporting and analysis of performance.<br />
Such reports and analyses provide<br />
the basis for control over expenditures<br />
and useful data for identifying the<br />
causes of operating problems.<br />
This model of management control<br />
systems is applicable to any organization<br />
and is used as a framework for<br />
discussing .programming, budgeting,<br />
and control in health care institutions.<br />
Superirnpo.ed over the provider organizations<br />
are severa] layers of planners,<br />
regulators, etc., each trying to manage<br />
the system. As the focus of the discussion<br />
is on provider institutions, these<br />
interests are viewed as constraints and<br />
external factors which impinge upon<br />
the PBCP. It is recognized that these<br />
constraints can be influenced by providers,<br />
but this type of interaction is<br />
not discussed here.<br />
The remainder of this paper presents<br />
a discussion and evaluation of the state<br />
of the art of PBCP, with a distinction<br />
being made between state of the art,<br />
(i.e., that which is technically possible)<br />
and the state of practice (i.e., that<br />
which is currently being employed in
- 183 -<br />
the health care industí , While much<br />
of the discussion is focused on the<br />
nonprofit, nongovernment hospital industry,<br />
many of the process-. -nd<br />
issues are relevant to other health care<br />
provider groups. Because the topic area<br />
of PBCP subsumes other 0reas of financial<br />
mana¿ement, and because it overlaps<br />
with many other areas of management<br />
activities not typically associated<br />
with financial management, discussion<br />
here must be narrowly focused. The<br />
paper presents a normative model of<br />
the three processes (i.e., PBCP) and<br />
discusses several issues related to the<br />
gap between the state of the art and the<br />
state of practice. To accomplish this,<br />
the paper is divided into tibe¿ parts.<br />
The first section provides a orief his<br />
torical perspective to PBCP and sur.<br />
marizes several important external<br />
pressures currently imposed on the<br />
health care industry. The second section<br />
presents a generic model of each of<br />
the three processes (PBCP). The elements<br />
of the models and the relationships<br />
between their elements are highlighted.<br />
The final section discusses<br />
several issues associated with orientation,<br />
design and implementation of<br />
PBCP currently practiced in the hospital<br />
field.<br />
Background-Legacy and<br />
Inertia<br />
As the hospital industry developed<br />
from a cottage industry to being the<br />
nucleus of a technologically sophisticated<br />
health care system in the early<br />
1970s, it did so with few constraints.<br />
Each institution had cash-flow concerns<br />
like any other economic entity;<br />
however, major programming decisions<br />
were made largely independent of any<br />
external planning or regulatory bodies.<br />
By 1970, the hospital industry was<br />
undergoing rapid growth in the hope of<br />
fulfilling the promise that "high quality<br />
Health Services Research<br />
health care was d -:;ht." The inertia<br />
generated by this period is still influencing<br />
managerial decisions and has<br />
left the industry with a legacy of high<br />
and rapidly increasing costs. Enthoven<br />
[4, p. 12291 summarizes the management<br />
philosophies that have resulted:<br />
In the system of fee-for-service,<br />
cost reimbursement and third.<br />
party intermediaries that dominate<br />
health care fiaancini today, the<br />
question of efficient use of resources<br />
does not even arise. The<br />
problem of how best to spend a<br />
given amount of money for the<br />
health care of c pupulation is not<br />
posed. Providers are not required<br />
to set priorities, look at alternatives<br />
and make hard choices. From the<br />
point of view of the provider, there<br />
is an apparently unlinrited amount<br />
of money. The system rewards<br />
cost-increasing behavior with more<br />
revenue; it punishes cost-reducing<br />
behavior with less revenue. Such a<br />
system must produce inflation in<br />
prices and waste in the use of<br />
resources.<br />
To better understand the elements of<br />
this philosophy as they relate to PBCP,<br />
four general areas of planning concern<br />
are discussed: service mix, production<br />
efficiency, production effectiveness,<br />
and capacity.<br />
Service Mix. The miy of services<br />
available in a given hospital was influenced<br />
by the rapid technological<br />
change in the medical field [5], the high<br />
degree of medical specialization [61,<br />
and the ability of hospitals to rapidly<br />
adopt new technologies. The rapid<br />
technological change was stimulated<br />
by research funded through the federal<br />
government, as well as universities,<br />
foundations, and industry. The resultant<br />
new clinical technology required<br />
expensive and highly specialized hospital<br />
facilities.. The clinical efficacy of<br />
these technologies were often not ques-
fioned or tested 1[7 and the cost-based<br />
reimbursement adopted by Medicare<br />
and Medicaid programs," .. created<br />
an unprecedented opportunity for physicians<br />
and hospital administrators to<br />
do what they always wanted to d'.improve<br />
the quality of care as they see<br />
it. This means more equipment, more<br />
personnel, more tests, more x-rays, and<br />
so on" [8, p. 94]. This natural tendency<br />
of health care providers and administrators<br />
received both moral and fiscal<br />
support from the federally financed<br />
Regional Medical Program created in<br />
1965. As a result, no hospital wanted to<br />
be technologically inferior and sought<br />
to provide a wide range of services<br />
regardless of the impact (or lack<br />
thereof) on the health status of its<br />
service population or the resultant duplication<br />
of services.<br />
Production Efficiency. The hospital<br />
industry is often characterized as having<br />
few inherent incentives for efficiency.<br />
The profit motive is generally<br />
lacking, contributions have historically<br />
allowed many hospitals to operate at a<br />
loss, health insurance programs have<br />
insulated the consumer from the provider,<br />
and the guaranteed payment of<br />
cost-based reimbursement have created<br />
an environment in which managers<br />
have had little need or incentive to<br />
strive for efficient production of services<br />
[8]. In addition, cost-based reimbursement<br />
even provides disincentives<br />
to reduce costs through improved efficiency<br />
[9, pp. 165-1671. As a result,<br />
hospital management has generally<br />
failed to introduce efficiency-minded<br />
styles of management and similarly<br />
failed to develop information systems<br />
necessary for proper control.<br />
Production Effectiveness. Historically,<br />
hospitals have had little concern<br />
about providing the right number and<br />
right types of health services to their<br />
- 184 -<br />
service populations. Until recently, few<br />
people have questioned medical judgments<br />
regarding admcissions, length of<br />
stay, and surgery rates. As a result, the<br />
incentives inherent in the fee-for-service,<br />
litigation-prone health care system<br />
have dictated the modus operandi,<br />
and increasing evidence of excessive<br />
utilization is surfacing l10,11].<br />
Capacity. While the medical profession<br />
operated on the "more is better"<br />
philosophy described above, hospital<br />
administrators developed a "bigger is<br />
better" philosophy toward facility<br />
planning. The availability of donations,<br />
the guaranteed reimbursemcnt of depreciation<br />
and interest expense by<br />
Medicare, Medicaid, and many Blue<br />
Cros: programs, and the availability of<br />
debt financing provided hospitals with<br />
sufficient means to add to their bed<br />
complement and replace existing facilities.<br />
Even though regional planning<br />
was an intended feature of the iiill-<br />
Burton Program, the Regional Medical<br />
Program, and later the Comprehensive<br />
Health Planning Act, large numbers of<br />
unused hospital beds are found in mosi<br />
regions of the couiry. rhe depreciation,<br />
interest, and ope:ating expenses<br />
associated with these facilities and subsequent<br />
replacement costs are all considered<br />
legitimate expenses and reimbulrsed<br />
ur.der cost-based reimbursement.<br />
As a .result, there have been few<br />
financial constraints or penalties<br />
linked to excessive capacity.<br />
While many other forces and activities<br />
were at play prior to 1970, those<br />
cited above were instrumental in shaping<br />
the hospital industry as it is currently<br />
operating. Programming decisions<br />
were made based on the "more is<br />
better" and "bigger is better" philosophies<br />
adopted by the medical staff,<br />
administration, and trustees. There was<br />
apparently little concern for the efficient<br />
allocation of resources since there
- 185 -<br />
was apparently no scarcity. The net<br />
result is the often cited increase in<br />
hospital costs.<br />
Given the trends toward raic,.y increasing<br />
costs of health care, the early<br />
1970s saw the federal government, state<br />
governments, and private industry exert<br />
pressure on the hospital industry.<br />
These major purchasers of health care<br />
services began to recognize that they<br />
would soon be unable to afford the<br />
health care system which was evolving.<br />
The attempts to control systems costs<br />
include rate regulation [121, controls on<br />
capital investments, budgeting requirements,<br />
and utilization review. The associated<br />
regulations act es constraints<br />
to the PBCP.<br />
Attempts to control capital invr -<br />
ments include the early comprehensi, ¡<br />
health planning structure, state certificate<br />
of need requirements, and certificate<br />
of need review mandated by P.L.<br />
93-641. Under P.L. 93-641, states are<br />
required to designate an agency which<br />
performs a reviewing and comment<br />
process for capital expenditures which<br />
exceed $150,000, change the bed supply,<br />
or substantially change the services<br />
of the facility. P.L. 93-641 also<br />
authorizes health systei;.s agencies to<br />
recommend to this state agency<br />
whether new institutional health services<br />
should be improved or not. While<br />
the experience of such programs is<br />
mixed [13,14], the process of requiring<br />
hospitals to justify proposed expenditures<br />
does force a level of planning not<br />
previously observed. Moreover, the<br />
federal government and some states<br />
have made inroads in defining and<br />
implementing quantitative criteria<br />
based on conservative estimates of justifiable<br />
demands 115,16].<br />
Annual operating budgets and capital<br />
budgets with a three-year planning<br />
horizon are mandated of all hospitals<br />
under Section 234 of P.L. 92-603 [17,<br />
p. 369]. While the law can make this<br />
Health Services Research<br />
requirement of a piucess, it cannot<br />
insure that the process is effective in<br />
the context of the management control<br />
process outlined in Figure 1.<br />
Professional standards review is<br />
another effort to affect costs by monitciing<br />
the appropriate use of hospital<br />
services. "But since the mechanism is<br />
that of peer review-one physician<br />
vis-h-vis another-the conflict of quality<br />
versus cost is immediately established,<br />
and with the emphasis on the maximizing<br />
of care, the net result may be<br />
increased rather than decreased services"<br />
[18, p. 6).<br />
The four categories of regulatory programs<br />
represent direct attempts to lower<br />
the rate of increase in hospital costs by<br />
1) providing services which are medically<br />
necessary rather than simply demanded,<br />
2) reducing the capacity of the<br />
system to correspond to so.-.c -,,tifiable<br />
demand for medical services, and 3)<br />
providing incentives for production efficiency<br />
and effectiveness.<br />
The models of the programming,<br />
budgeting, and controlling processes<br />
presented in the next section adopt<br />
these three objectives for institutional<br />
planning and control. (Cnst-effective<br />
planning is the term used by Dowling<br />
to refer to "determining the least costly<br />
arrangement of facilities and services<br />
consonant with community needs" [19,<br />
p. 26). The two definitions are seen to<br />
be identical in meaning.) It should be<br />
noted, however, that cost-effective<br />
planning as defined here does not<br />
necessarily coincide with the private<br />
interests of health care providers. It is<br />
this inherent conflict of interests which<br />
spawns many of the issues discussed in<br />
the final section of this paper.<br />
Programming, Budgeting, and<br />
Control-A Model of Processes<br />
This section presents an overview of<br />
the state of' the art of programming,
udgeting, and controlling processes<br />
(PBCP) for health care institutions.<br />
Schematic diagrams of each of the th.,:.<br />
processes are presented (Figures 2, 3,<br />
and 5) for the purposes of highlighting<br />
the important data elements, relationships,<br />
and decision points. These diagrams<br />
are not intended to preclude<br />
additional considerations or steps leading<br />
toward decisions, and the ensuing<br />
discussions must, because of space<br />
constraints, be restricted to general<br />
characteristics of the diagram elements.<br />
(For more detailed discussions of methodological<br />
options, evaluations, etc.,<br />
see [201.)<br />
Programming Phase<br />
In the management control model<br />
described above, the initial planning<br />
step is that of deciding on the strategic<br />
plans for the organization. Once decided,<br />
the programs to be undertaken<br />
and the approximate amount of resources<br />
to be allocated to each program<br />
are determined. The outputs of this<br />
programmng process are decisions regarding<br />
the revenues, expenses, and<br />
capital requirements of patient care,<br />
teaching, research, and overhead programs;<br />
facility size; and objectives in<br />
the area of improving or ensuring production<br />
efficiency and effectiveness.<br />
The programming decisions are based<br />
on four major categories of informetion<br />
(see Figure 2).<br />
Marketing Information. The market<br />
served by the hospital should be understood<br />
well enough to permit costeffective<br />
planning, i.e., to determine<br />
the least costly arrangement of facilities<br />
and services, consonant with community<br />
needs. This should include three<br />
important types of information: 1) determination<br />
of service population of the<br />
hospital and its characteristics 121], 2)<br />
assessment of medical needs of the<br />
service population [221, and 3) assess-<br />
- 186 -<br />
Programing, Budgeting, and Control<br />
ment of potential areas for cooperation<br />
with other hospitals and providers [23].<br />
It is recognized that difficulties arise in<br />
trying to define and measure need fnr<br />
medical services [24]. As a result, many<br />
of the contemporary planning models<br />
and the marketing information are demand<br />
based. It should be noted that<br />
increasingly hospitals are trying to influence<br />
the amount and configuration<br />
of their demand through various marketing<br />
efforts.<br />
Organizational Goals and $.trmiegic<br />
Plans. The developmeni, statement,<br />
and updating of organizatiorlal goals<br />
and strategic plans is the second major<br />
cf-t.gory of information necessary for<br />
;h- programming process. These goals<br />
initially provide direction for the decision<br />
process and, later, become yardsticks<br />
along which various program;.3<br />
can be evaluated. It is important that<br />
the formulation of these goals reflect<br />
- inputs from a variety of individuals<br />
within the organization, e.g., trustees,<br />
administrators, depar,..en* heads, etc.<br />
[17]. Such an exchange of ideas between<br />
individuals at the different levels<br />
not only provides useful suggestions<br />
in the planning process, but helps<br />
foster a córr-itment to the organization<br />
arid its plans [25].<br />
Previous Year's Performance. The<br />
feedback loop in the general management<br />
control process can suggest areas<br />
whete adjustments are necessary and<br />
areas where expectations should be<br />
changed. The primary use of this information<br />
is the .evaluation of ongoing<br />
programs [3, Chap. 91, and the data is<br />
generated during the Controlling Phase<br />
which is discussed below.<br />
Externa) Constraints. The hospital<br />
industry operates within a larger legal<br />
and economic system and is regulated<br />
by a host of statutes and agencies.
ut,<br />
u<br />
a.<br />
íL<br />
._c<br />
E<br />
0<br />
t42<br />
a ..<br />
0m<br />
u<br />
y<br />
E<br />
o,<br />
- 187 -<br />
Health Services Research
- 188 -<br />
Consequently, hospital programming<br />
decisions must be made with a full understanding<br />
of the reimbursemnt restrictions,<br />
legal constraints, tax culnsiderations,<br />
and certificate of L.eed restrictions<br />
associated with each program.<br />
Information from these four categories<br />
are necessary for hospital managers<br />
to make cost-effective programming decisions.<br />
A purely algorithmic approach<br />
to programming decisions is not available,<br />
and it is doubtful whether one<br />
could be of much benefit given the<br />
complex nature of organizational decision<br />
making. Such decisions generally<br />
result from consideration of a large<br />
number of political, competitive, social,<br />
economic, and persone i cencerns.<br />
The application of algorithms would<br />
undoubtedly be plagued with the same<br />
types of conceptual and measurement<br />
problems identified with cost-benefit<br />
analysis [261.<br />
Nevertheless, useful decision models<br />
have been developed for several types<br />
of programming decisions that are conceptually<br />
consistent with the objective<br />
of cost-effective decision making.<br />
Where they can differ, and where application<br />
is weakened, is ofen in the<br />
specification of key parameters. A<br />
number of these models are cited<br />
below.<br />
Facility Requirements. Dowling [271<br />
identifies five steps for translating demand<br />
forecasts into facility requirements.<br />
1. Identify the facility units (e.g., medical/surgical<br />
beds, obstetrical beds,<br />
operating rooms, x-ray units, etc.)<br />
associated with each major medical<br />
service (e.g., deliveries, surgical<br />
procedures, etc.).<br />
2. Determine the service producing capacity<br />
of a single facility unit.<br />
3. Determine the number of facility<br />
units required to accomodate the<br />
average demand for service.<br />
Programing, Budgeting, and Control<br />
4. Determine the nunuer of additional<br />
facility units that must be available<br />
to accommodate emergency demands<br />
or peak loads based on the<br />
desired level of protection sought<br />
(the reserve or standby requirement).<br />
5. Calculate the total number of facility<br />
units required and the load factor<br />
(e.g., occupancy level) from the results<br />
of Steps 3 and 4.<br />
The calculations associated with each<br />
step are necessary to match Lise capacity<br />
of a facility unit to it.s expected<br />
demand in an efficient iwai. The demand<br />
estimates are derived from service<br />
population estima t cs 121,28). Reductions<br />
in use rates based on normative<br />
standards can be made to demand<br />
estimates (use rates for fixed service 4<br />
population) to provide activity levels<br />
that are closer to need than the observed<br />
demand [16]. The validity of<br />
such a reduction is based on an as-<br />
.sumption of excessive utilization due<br />
to excessive supply and inefficient<br />
management of medical services 16, pp.<br />
96-100; 10,16,29]. )nce the demand is<br />
characterized, four gei.aral approaches<br />
can be used to determine the total<br />
facility requirements [27]:<br />
1. Use o doormative occupancy levels<br />
(e.g., build and/or staff enough medical/surgical<br />
beds to provide an 85<br />
percent occupancy level).<br />
2. Analyze the past census data to<br />
identify the number of beds neces-<br />
,sary to accommodate the expected<br />
census, x percent of the time (e.g., 95<br />
percent of the time).<br />
3. Apply a formula based on an assumption<br />
of a simple (generally<br />
Poisson) distribution of arrivals.<br />
Such models range from the simple<br />
square root model used by the Hill-<br />
Burton Program [30] to more complex<br />
mathematical formulations (see<br />
analysis and references in 1311).<br />
4. Simulation models for more com-
plex stochastic distribution of arrivals<br />
and census data 132, Chap. 7].<br />
These models should be quite useful<br />
for determining target bed sizes of<br />
hospitals. When applied to institutional<br />
planning, the need for cooperation<br />
between health facilities is apparent.<br />
The technology has not been developed<br />
to the same degree for sizing<br />
ancillary departments. (Useful studies<br />
include those by Thomas and Stokes<br />
[331], and Conrad et al. 1341.)<br />
Support Services. All organizations<br />
incur systems' costs for "overhead programs."<br />
The mix, scope, and level of<br />
such programs must be addressed in<br />
the programming phase. Neumann (351<br />
discusses why such programs often go<br />
unevaluated and how organizations<br />
have a natural tendency to foster their<br />
growth. Overhead value analysis [351<br />
and functional value analysis [361 are<br />
pragmatic methods for evaluating the<br />
worth of such overhead programs tosthe<br />
organization.<br />
For almost every overhead service,<br />
there is an implicit "make versus buy"<br />
decision. Increasingly, hospitals are<br />
buying many services (e.g., management<br />
contracts, food services, data processing,<br />
etc.) and increasingly, hospitals<br />
are looking to shared service arrangements<br />
with other hospitals for fiscal<br />
services, purchasing, laundry, etc.<br />
Programs to Improve Production Efficiency<br />
and Effectiveness. Significant<br />
cost savings can be achieved by implementing<br />
contemporary' admissions<br />
scheduling systems, preadmission testing,<br />
concurrent review, and outpatient<br />
surgery [371. Successful implementation<br />
of these methodologies requires<br />
considerable advanced planning/programming<br />
to develop the requisite data<br />
systems [38] and to develop the necessary<br />
support from critical actors in the<br />
system [39]. The involvement in this<br />
- 189 -<br />
Health Services Research<br />
planning process of all affected parties<br />
and the "top-down" support is essential<br />
to the successful implementation of<br />
these efficiency methodologies.<br />
The importance of these methodologies<br />
in the efficient management of<br />
patient services should be noted. A<br />
hospital which for example does not<br />
have a preadmission testing program<br />
and outpatient surgery will experience<br />
a higher inpatient census than if the<br />
hospital had the programs. Using the<br />
approaches described above, this<br />
higher demand will be translated into<br />
more hospital beds. Thus, for the same<br />
medical services, a larger inpatient facility<br />
would be justified. In addition, if<br />
'admission and operating room scheduling<br />
systems were not used, the variance<br />
of admissions would likely be higher,<br />
thus justifying more beds for the same<br />
target occupancy. In both cases, implementation<br />
of these efficiency technologies<br />
will tend to reduce the number<br />
of necessary beds for the service<br />
population. If the facility resizes accordingly,<br />
it will probably increase<br />
outpatient expenses, but there should<br />
be net savings.<br />
It is through the programming decisions<br />
identified above and in Figure 2<br />
that hospitals can plan in advance how<br />
to allocate resources and provide facilities<br />
and services which meet the needs<br />
of the population served, while minimizing<br />
capital and operating costs.<br />
These decisions provide the context<br />
within which budgeting and control<br />
decisions are made and, to a large<br />
extent, set the stage for a hospital's<br />
level of production efficiency and effectiveness.<br />
The major cost-related decisions<br />
are program decisions; budgeting<br />
and control can be viewed as fine<br />
tuning.<br />
Budgeting Phase<br />
The programming decisions provide<br />
the fiscal officer alid budget committee
with a programmatic statemer.t of organizational<br />
objectives. Du.iig the<br />
budget process, the approved programs<br />
are translated into a detailed statement<br />
of monetary requirements and financi_;<br />
consequences, i.e., the budget package<br />
is prepared.<br />
The process of budgeting is useful to<br />
management because it formalizes<br />
communication between the hospital's<br />
governance, administration, department<br />
heads, and others. This dialogue<br />
serves a useful plannng function and<br />
can be extremely important if the budget<br />
is to be used effectively in the<br />
control process. "Management by objectives"<br />
is a formal program to facilitate<br />
and improve the effectiveness of<br />
this process [40].<br />
The end result of the budgeting process,<br />
the budget package, can serve<br />
three major functions. First, it describes<br />
the implementation and consequences<br />
of the programming decisions in the<br />
preceding step. Thus, it may be viewed<br />
and used as a simulator of financial<br />
consequences of programming decisions.<br />
Second, the approved budget is<br />
used as a standard in the control process.<br />
Thus, the measures of performance<br />
(often costs) must be stated in<br />
terms of responsibility (discussed below).<br />
The budget's third function is in<br />
the area of reimbursement. In some<br />
states, rate setting programs of third<br />
party participating contracts require<br />
hospitals to negotiate an expense budget.<br />
Subsequent reimbursement is then<br />
based on the results of this negotiation<br />
process. When a budget is used in a rate<br />
setting context, it may reflect ploys to<br />
increase reimbursement rather than accurately<br />
reflecting management intentions.<br />
If this is the case, te budget<br />
would have questionable value in the<br />
controlling phase.<br />
There are several ways of structuring<br />
the budget schedules depending upon<br />
management needs. Four dimensions<br />
- 190 -<br />
to this structure are identified and<br />
discussed below.<br />
Basis of Accumulating Costs. The<br />
expense budget is a key operating budget<br />
and the basis of accumulating costs<br />
represents the basic unit for planning<br />
and control. Management faces a<br />
choice of bases, and four commonly<br />
cited options are:<br />
1. Line items. A budget developed on<br />
this basis would show expenses<br />
grouped by major items of expenditures<br />
for the entire organization, e.g.,<br />
salaries broken into several categories,<br />
medical supplies, laboratory<br />
supplies, etc. With expelises accumulated<br />
this way, management can<br />
control items of expenditure and<br />
plan for their use. There is, however,<br />
no clear link to output and such a<br />
classification fails to identify responsibility<br />
for expenditures.<br />
- :. Program. A budget prepared on this<br />
basis would augment the programs<br />
identified in the programming pr,h.sby<br />
showing more 'l.taile:l budgets<br />
for each program. Using such a base,<br />
organizations must decide whether<br />
they are planning for or intend to<br />
control only the direct program costs<br />
or the full program costs (direct plus<br />
indirect). in either case, this method<br />
of preparation .is useful in planning,<br />
but often fails to accumulate costs<br />
along lines of responsibility. Thus,<br />
the control function is subverted.<br />
3, Medical Services. A budget prepared<br />
using this basis identifies the costs<br />
associated with each category of<br />
medical services. Costs can be defined<br />
in total, on a per-unit basis,<br />
and by direct and indirect costs.<br />
Bundles of medical services associated<br />
with specific diagnoses are<br />
the base proposed by Thompson<br />
(411.<br />
4. Responsibility Center. Costs are ac-
- 191<br />
cumulated according to any organizational<br />
unit headed by a responsible<br />
manager. In many cases these<br />
responsibility centers correspond to<br />
departments, although not necessarily.<br />
Budgets prepare¿ using this<br />
basis are quite useful for controlling<br />
expenditures, but often lose their<br />
direct usefulness in planning based<br />
upon medical needs of a service<br />
population. In addition, the control<br />
function can be hampered in cases<br />
where areas of responsibility overlap.<br />
Fixed versus Flexible Budgets. A<br />
fixed budget is one developed using a<br />
single estimate of activities. The usefulness<br />
of such a budget is contingent<br />
upon the accuracy of the activity forecasts.<br />
A flexible budget is essentially a<br />
set of fixed budgets covering a specified<br />
range of activity levels [17,42,43].<br />
Time Periods. The expense foresast<br />
can correspond to the budget year, in<br />
total, each of the four quarters, each of<br />
the 12 months, or 13 four-week periods.<br />
The smaller the unit of time, the more<br />
tedious the planning process. However,<br />
the ability to use variable budgeting<br />
(i.e., coordinating staffing levels with<br />
seasonal variations in demand) can<br />
only be accomplished efficiently with<br />
reasonably small units of time. In addition,<br />
the specified period of time is<br />
directly related to the time lag between<br />
the occurrence of unfavorable performance<br />
and its detection using budget<br />
reports.<br />
Continuous or Discrete. A budget can<br />
be prepared on a discrete basis, i.e., a<br />
fixed 12-month period, or on a continuous<br />
basis, i.e., the budget is updated on<br />
a monthly or quarterly basis, always<br />
extending 12 months in advance.<br />
Management can select any combination<br />
of these different types of budgets,<br />
Health Services Research<br />
each with their own strengths and<br />
weaknesses. For our purposes, it is<br />
assumed that the budget is being prepared<br />
for a 13-period year [44] on a<br />
discrete basis, accumulating costs by<br />
responsibility center [21 and on a fixed<br />
basis. (The benefits of flexible budgets<br />
in the planning process will depend on<br />
the uncertainty of activity levels. In<br />
cases of high uncertainty, a flexible<br />
budget should be used to specify the<br />
range of options and consequences.<br />
However, at some point, a "likely"<br />
activity level will have to be assumed.<br />
For control purposes, other means can<br />
be used to analyze performance.) Having<br />
made these assumptions, we can<br />
discuss the three principal steps in the<br />
budgeting phase (see Figure 3).<br />
Step 1 generates forecasts of the<br />
activity levels for each responsibility<br />
center, for each of the 13 periods. In<br />
some cases, mathematical models employing<br />
the historical data (time series,<br />
leading indicators, causal factors, and/<br />
or some combination) can be quite<br />
useful for predicting activity levels [32.<br />
45-471. In other cases, historical data<br />
has little bearing on the future. For<br />
example, when a new medical service<br />
is implemented, there is no experience<br />
on which to base forecasts. In all cases,<br />
there will be some risk associated with<br />
each forecast. Any biases associated<br />
with the forecasts of activity levels<br />
should be identified to the extent possible,<br />
since forecasts of expenses and<br />
revenues will generally reflect the same<br />
bias. In practice, the forecasting of<br />
activity levels is seen as a combined<br />
quantitative and qualitative approach.<br />
That is, historical data and mathematical<br />
models can be useful for identifying<br />
trends and underlying relationships;<br />
however, department heads' understanding<br />
of exogenous and endogenous<br />
factors which bear upon the future<br />
must be subjeciively weighed in the<br />
forecasts.
1'<br />
- 193 -<br />
Step 2 represents the heart of an<br />
efficient budget preparation process. In<br />
this step, expected levels of output are<br />
translated into resource requirements,<br />
i.e., personnel at various levels, supplies,<br />
etc. The intent is to match an<br />
efficient level of inputs with the expected<br />
level of output, given a desired<br />
level of quality. For two major areas of.<br />
requirements-manpower 'and supplies-major<br />
elements of the process<br />
can be highlighted.<br />
Manpower Requirements. Salary expenses<br />
represent 55 to 70 percent of a<br />
hospital's total expenses. Thus manpower<br />
budgets represent a major area of<br />
budgetary concern. Warner (481 discusses<br />
the current research on nurse<br />
staffing, scheduling and reallocation<br />
activities. McNally 1491 evaluates six<br />
techniques for evaluating manpower<br />
levels/needs for many hospital departments.<br />
Kaplan [50] uses regression<br />
analysis to staff different nursing units.<br />
These formula-based approaches tó<br />
staffing decisions can be effective if<br />
there is significant department head<br />
input into staffing standards [51]. Lipson<br />
and Hensel [52] describe a manpower<br />
budget process which is based<br />
on negotiation between responsibility<br />
center heads and administration. Such<br />
participation in which department<br />
heads not only formulate but commit<br />
themselves to performance levels is<br />
considered important for an effective<br />
control system [53]. Through practice,<br />
careful feedback and commitment, activity<br />
indexes can be developed for<br />
specific nursing units, and production<br />
functions developed for ancillary departments<br />
which represent efficient<br />
and agreed upon technologies.<br />
Supply Requirements. Supplies vary<br />
from approximately 5 percent of nursing<br />
unit expenses to 75 percent for<br />
pharmacy. For many departments, the<br />
Health Services Research<br />
amount of supplies used can be correlated<br />
to some level of hospital output,<br />
e.g., patient-days, surgical procedures,<br />
etc. Estimated relationships (with an<br />
adjustment for inflation) can be used to<br />
forecast the amount of supplies for each<br />
department. An effective materials<br />
management program can reduce supply<br />
costs, including distribution and<br />
inventory costs [541.<br />
The important elements of this resource<br />
identification step are to 1)<br />
attempt to develop an input-output<br />
model for each department and 2)<br />
allow department heads to participate<br />
in developing the model to be used for<br />
their department. The models can be<br />
developed using historical data 1551 or<br />
can be constructed using subjective<br />
estimates of the parameters [561. Caution<br />
must be exercised that past inefficiencies<br />
are not perpetuated, but the<br />
actual process of trying to understand<br />
the use of inputs for different levels of<br />
output will have educational benefits<br />
to administrators and department<br />
heads. By making current patterns of<br />
resource use explicit, the status quo can<br />
be challenged and better ways sought.<br />
(Zero-based budgeting is a systematized<br />
approach to categorizing and<br />
judging current expenditures l571.) The<br />
field testing of these better ways and<br />
feedback through the budget reporting<br />
system provide the potential for period<br />
by period improvements in performance.<br />
The operating and financial budgets<br />
are prepared in Step 3. It is important<br />
that the full consequences of the hospital's<br />
set of plans are identified. Following<br />
the completion of Step 2, financial<br />
officers must predict or set salary levels,<br />
fringe benefits, supply prices,<br />
utility expenses, interdepartment<br />
charges, etc., in order to complete the<br />
expense budget. With the expense budget<br />
completed, revenues from costbased<br />
reimbursers can be estimated,
and charges set at a level to co. r total<br />
financial requirements [58]. Total financial<br />
requirements are the sum of<br />
operating expenses (patient care, teack<br />
ing, research, etc.) and capital needs<br />
(working capital, purchases of plant<br />
and equipment, etc.). The setting of<br />
charges involves decisions about crosssubsidization<br />
of departments and input<br />
from responsibility heads. Integrating<br />
these two budgets yields the pro forma<br />
income statement which can be used in<br />
preparing the cash budget, finalizing<br />
the capital budget, and preparing the<br />
pro forma balance sheet.<br />
This package of budgets should be<br />
viewed as a model of interrelated decisions<br />
where one financial decision influences<br />
a number of others (see Figure<br />
4). For example, decisions regarding<br />
long-term financing directly influence<br />
the cash budget, the expense budget,<br />
and the revenue budget (in particular<br />
the setting of charges). Understanding<br />
these interrelationships enables the<br />
budget package to be used as a simulation<br />
device whereby a set of programming<br />
decisions can be used to estimate<br />
activity levels, and resource requirement<br />
assumptions can be examined in<br />
terms of the financial consequences<br />
displayed in the budget package. Computerizing<br />
such a model can enhance<br />
its usefulness 159).<br />
Controlling Phase<br />
The concern in this section is with<br />
the control of performance at the responsibility<br />
center level rather than<br />
the more general management control<br />
process shown in Figure 1. The focus<br />
is on evaluation of operational performance<br />
where the results ,! the planning<br />
phases are considered "givens"<br />
[1, Chap. 1]. It is important that both<br />
financial and nonfinancial performance<br />
be evaluated in this retrospective<br />
analysis. The evaluation of financial<br />
performance generally begins with<br />
- 194 -<br />
Programing, Budgeting, and Control<br />
an analysis of operating .rd financial<br />
budgets relative to actual performance.<br />
Typically, this so-called Budgetary<br />
Control process stops with the financial<br />
review. However, for nonprofit<br />
health care organizations, nonfinancial<br />
objectives are often key elements of<br />
strategic plans and programming decisions.<br />
Consequently, a valid analysis<br />
of performance miust include an evaluation<br />
of nonfinancial characteristics<br />
of operations.<br />
Management must develop the structure<br />
and processes of its control systems,<br />
taking into consideration the ability<br />
to detect deviant behavior as well as<br />
the systems' effect on emplcyee behavior.<br />
The detection concerns are disc.ssed<br />
below. The behavioral concerns<br />
inciude the following: 1) Does the<br />
control system induce behavioral patterns<br />
that are conducive to achieving<br />
organizational objectives? 2)What unintended<br />
behavioral effects does the<br />
control system have? and 3) What latitude<br />
does the system provide for<br />
people to implement ploys? These behavioral<br />
concerns have been explored<br />
in the literature 19, p. 75; 25,53,60].<br />
These studies, and others, emphasize<br />
the importance of such elements as<br />
participaticn, Pccurate information systems,<br />
communication, and incentives.<br />
This last consideration is receiving<br />
considerable attention in the hospital<br />
industry and a number of hospitals<br />
have explored profit sharing or incentive<br />
payment programs with their employees<br />
161-63). I<br />
The major elements of the controlling<br />
phase are summarized in Figure 5. At<br />
the heart of this phase is an analysis of<br />
performance in which expected outcomes<br />
are compared with actual outcomes.<br />
For the operation and financial<br />
aspects of the organization, the operating<br />
and financial budgets generally provide<br />
the expected outcomes. They represent<br />
the best plans resulting from<br />
1
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- 196 -<br />
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- 197 -<br />
analysis, forecasting, and negotiation<br />
activities in the programming and budgeting<br />
phases. For the nonfinancial objectives,<br />
explicit statements of expectations<br />
should be available from the planning<br />
phase.<br />
Information about actual outcomes<br />
should be available from the organization's<br />
management information system.<br />
The data should be accurate, provided<br />
on a timely basis, and must be comparable<br />
with data from the budgeting<br />
system. This generally means that the<br />
hospital's financial accounting system<br />
must have the ability to 1) accumulate<br />
expense items by responsibility center,<br />
2) provide cost accounting systems for<br />
calculating per-únit costs, and 3) collect<br />
operating statistics as an integral<br />
part of the systematic management information<br />
system. Davis and Freeman<br />
(641 offer some suggestions on how to<br />
evaluate management information systems,<br />
and DATAPRO [651 specifies<br />
some guidelines for judging commercial<br />
software packages.<br />
The assessment of performance<br />
should be as timely as data permits.<br />
The first cut at the analysis should be<br />
standardized management reports of<br />
four types:<br />
1. Productivity Monitoring. Reports in<br />
which the productivity (output +<br />
input) of responsibility centers and/<br />
or individual providers is measured.<br />
These reports compare actual measures<br />
with internal and/or external<br />
standards [17, Chap. 18; 66-681.<br />
2. Variance Analysis. Methodologies<br />
for estimating the difference between<br />
budgeted and actual accounts.<br />
Such analyses can be performed at<br />
the total or gross variance level for<br />
specific responsibility center or line<br />
items [691 or at the component variance<br />
levels [9, pp. 82-85; 701. Component<br />
variance analysis attempts to<br />
partition the total experience into<br />
Health Services Research<br />
parts which correspond to identifiable<br />
causes, e.g., price, volume, supply<br />
quantity, etc.<br />
3. Operational Audit. Process of examining<br />
the operations of departments<br />
and organizational control systems<br />
to assess their effectiveness. The<br />
process is concerned with problem<br />
detection rather than problem solving<br />
[711.<br />
4. Financial Statement Analysis.<br />
Methodologies for analyzing the organization's<br />
financial performance<br />
as a whole and assessing its financial<br />
position 172,73].<br />
The purpose óf this first cut analysis is<br />
to systematically identify problems<br />
and, to the extent possible, their apparent<br />
causes. When problems are indicated,<br />
further analysis and discussions<br />
with responsibility managers are generally<br />
necessary to identify the true<br />
causes and the appropriate courses of<br />
action.<br />
The reporting and analysis of performance<br />
serve several purposes. First, the<br />
reports are used to keep management<br />
informed of what is happening in the<br />
different responsibility centers. Management<br />
can, when necessary, take appropriate<br />
action on the basis of these<br />
reports, or can initiate additional analyses.<br />
Second, they can be used to evaluate<br />
the performance of responsibility<br />
center heads. Third, such reports may<br />
indicate that the budgeting process<br />
should be altered. Fourth, the reports<br />
can be useful in educating department<br />
heads to the financial consequences of<br />
their decisions. Without such reports,<br />
department heads may be unable to<br />
make staffing and scheduling decisions<br />
which are consistent with the overall<br />
goals of efficiency and effectiveness.<br />
The controlling phase should be<br />
viewed as a feedback loop to the<br />
programming and budgeting phase.<br />
Analyzing performance will have little
- 198 -<br />
useful effect if it is done aF an independent<br />
management acu .;;y. However,<br />
if conducted for the purposes of<br />
improving the planning and budgeting<br />
processes, gaining a better underst ,,.'.<br />
ing of production processes, and improving<br />
management skills, performance<br />
evaluation can be an essential<br />
link in a hospital's attempt to improve<br />
its cost effectiveness.<br />
State of the Art-Issues and<br />
Failings<br />
The models presented in the preceding<br />
section outline the scope and elements<br />
of contemporary planning, budgeting,<br />
and controlling processes<br />
(PBCP). Their focus is on ccrurate<br />
cost-effective planning and effective<br />
management control. This section presents<br />
a number of issues associated<br />
with the orientation, design, and implementation<br />
of PBCP in the health<br />
field by highlighting the major reasons<br />
for observed differences between the<br />
state of practice and the state of the art.<br />
'Planning Attitudes<br />
There remains a significant gap between<br />
the public interest and the private<br />
interest of health care providers.<br />
The public interest was characterized<br />
in the first section as being served by<br />
cost-effective programming decisions,<br />
i.e., based on the health care needs of a<br />
service population and using criteria<br />
which maximize system efficiency and<br />
effectiveness. The private interest is,<br />
for the most part, still geared toward<br />
increasing technological capabilities,<br />
facility size, and the volume of patients,<br />
and not toward redur.ing the<br />
levels of expenditures. Exceptions do<br />
exist and, in some cases, this growth is<br />
consistent with development of rational<br />
networks and multiple hospital<br />
.systems. In many cases, however, this<br />
growth in assets and operating ex-<br />
penses is motivated by fear of becoming<br />
technologically obsoietc. fear of being<br />
labeled inferior to other hospitals, and<br />
fear of losing medical staff, patients,<br />
and status.<br />
As yet, the external constraints are<br />
still too loose to prevent hospitals from<br />
reacting to these fears out of pure<br />
self-interest. Enthoven 14, p. 1229]<br />
summarizes the attitude: ·<br />
The problem of how tc hest spend<br />
a given amount of money for the<br />
health care of a population is not<br />
posed. Providers are not required<br />
to set priorities, look at alterriativocs<br />
and make hard choicec<br />
While the debate contir.ues on how<br />
best tu improve institutional planning<br />
dttitudes (i.e.,, by increased direct ecou.omic<br />
regulation or restrucr.turing the<br />
financial incentives), efforts are being<br />
made to improve the means of making<br />
population-based decisions 174], and<br />
prominent students of the industry are<br />
raising the visibility of problems and<br />
methods of increasing cost-effective decision<br />
making, e.g., curtailmng the "fatof-the-curve<br />
medicine," stimulating regionalization<br />
of health care, introducing<br />
cost considerations into the physician's<br />
decision making process, and<br />
controlling the introduction of new<br />
technology j4].<br />
It should be noted that in the current<br />
environment, cost-effective planning<br />
decisions may be impractical and ineffective<br />
unless there is strong community<br />
planning. A hospital which is very<br />
discriminating in the types of medical<br />
equipment purchased, aggressive in reducing<br />
unnecessary utilization, and effective<br />
in managing the admissions to a<br />
properly sized facility runs the risk of<br />
losing its medical staff to competing<br />
hospitals that are less restrictive. Such<br />
a danger would, however, not be as<br />
great if similar efforts were being made<br />
by all hospitals in a community.
Budgeting Attitudes<br />
- 199 -<br />
The planning attitudes extend to the<br />
budgeting process; in particular, there<br />
is no indication that hospitals are motivated<br />
to develop technically efficient<br />
budgets. Many believe this results from<br />
the fee-for-service, cost-based reimbursement<br />
system which fails to provide<br />
real inceitives for efficiency.<br />
Under this system, there is little incentive<br />
to move away from peak-load<br />
staffing and to contend with the problems<br />
of part-time and temporary staff;<br />
there is little incentive to search for<br />
better modes of operation which might<br />
lower costs; and there is little incentive<br />
to say "no" to requests for additional<br />
staff which are intended to increase the<br />
quality of care without regrad to effectiveness.<br />
The negative effects of hospitals'<br />
ability to attract patients are<br />
greatly reduced by the widespread absence<br />
of these incentives and the general<br />
lack of competitive pressures in {ieindustry.<br />
The net result has been a<br />
widespread increase in costs, quantity<br />
and perhaps quality without any type<br />
of competitive or effective regulatory<br />
mechanisms for forcing the system toward<br />
an equilibrium' position.<br />
There appears to be concensus that<br />
this system will change through either<br />
more restrictive means of calculating<br />
reimbursement rates, or a restructuring<br />
of financial incentives. While this future<br />
scenario has not altered current<br />
budgeting decisions, it has increased<br />
hospital managers' desire for improved<br />
budgeting capabilities. In some cases,<br />
hospitals are preparing for this future<br />
environment by increasing their expense<br />
base with the hope that future<br />
restrictions will be less painful.<br />
In addition, many financial managers<br />
have sought to develop formulistic approaches<br />
to budgeting, e.g., developing<br />
departmental cost functions, and/or<br />
rigid productivity indexes. While these<br />
Health Services Research<br />
are important elements in the models<br />
described above, there is a danger that<br />
mathematical models will be used to<br />
develop the budget without department<br />
head input, review or understanding.<br />
Such a unilateral preparation process<br />
will reduce the effectiveness of the<br />
entire management control process and<br />
not be in the long-run interests of the<br />
hospital.<br />
Attitudes Toward Control<br />
The power structure in hospitals is<br />
such that management often finds its<br />
hands tied. Many decisions geared toward<br />
improving efficiency or insuring<br />
compliance with the budget often involve<br />
a perceived sacrifice by physicians<br />
and other professionals. Confrontations<br />
between administrators and the<br />
medical staff are often one-sided in that<br />
administrators are easier to replace<br />
than medical staffs. Since efficient behavior<br />
is not rewarded financially, nor<br />
does the system as yet demand efficient<br />
management, the route of choice is<br />
often the route of minimum resistance.<br />
Without clear directives and support by<br />
hospital boards, this cannot and will<br />
not change.<br />
Information Systems<br />
Accurate, valid, and timely data are<br />
essential for the management decisions<br />
described in PBCP. In an abstract sense,<br />
there are four key relationships which<br />
should be geherated from the information<br />
systems: costs per responsibility<br />
center, costs per inputs, inputs per<br />
.output, and cost per output. The information<br />
system must provide this data<br />
for the hospital's own operations and<br />
should include comparable data from<br />
other institutions. Drebin [75, p. 881<br />
criticizes the capabilities of many (not<br />
all) hospital information systems.<br />
(The hospital industry] is unable to<br />
define its product or quantify the<br />
value of its product, cannot specify
its production costs or explaibi .any<br />
those costs are increasing at a rate<br />
higher than the average rate of<br />
costs increase in the economy....<br />
- 200 -<br />
This current state of practice results<br />
more from a historical belief that managers<br />
did not need good information<br />
systems rather than from a set of<br />
unsolvable problems. There has simply<br />
been a general avoidance of implementation<br />
issues, largely in two<br />
areas: augmenting financial accounting<br />
systems for management purposes, and<br />
developing accurate cost-accounting<br />
systems.<br />
The financial accounting system of a<br />
hospital is frequently used to provide<br />
the basic financial information regarding<br />
operations. Because the financial<br />
accounting and managerial accounting<br />
functions are quite different [2, Chap.<br />
141. two major problems can arise.<br />
First, the data can be invalid for management<br />
decisions. The financial accounting<br />
system is based on externally<br />
determined standard accounting practices<br />
which are geared toward disclosure<br />
of financial information to the<br />
outside world. In developing these<br />
standard accounting practices, criteria<br />
are used which may not be consistent<br />
with management purposes, e.g., the<br />
criterion of objectivity often conflicts<br />
with the criterion of usefulness. This is<br />
illustrated in the accounting principles<br />
relating to the measurement of fixed<br />
assets. Financial accounting initially<br />
records an asset at cost (an objectively<br />
determined amount) and systematically<br />
reduces that value using depreciation<br />
methods (objective estimates). For<br />
the purposes of planning, it has been<br />
argued that the replacement cost of an<br />
asset is the more appropriate valuation<br />
base. The second problem arises in the<br />
definition of cost centers. There is<br />
considerable pressure for hospitals to<br />
adopt a uniform accounting system<br />
Programing, Budgeting, and Control<br />
[76], and there are fears ,.a! such a<br />
system will define cost centers on the<br />
basis of function rather than responsibility<br />
177]. If this occurs, using the<br />
financial accounting system for budgeting<br />
and control purposes will necessarily<br />
interfere with the effectiveness of<br />
the management control system [77].<br />
Attempts are being made to develop<br />
systems which are compatible with<br />
both functional and responsibility accounting<br />
[78].<br />
Historically, there has been little<br />
need to perform cost accounting beyond<br />
what was required bv third party<br />
reimbursement formulas. As a result,<br />
definitions of output have become synonymous<br />
with patient days and fee<br />
coúes. cost allocation is equated to the<br />
stea. down method, and statistical<br />
bases for allocation are selected if they<br />
maximize revenue rather than if they<br />
accurately reflect the use of overhead<br />
services. As a result, most hospitals<br />
findthemselves unable to measure the<br />
cost of programs, responsibility centers<br />
and specific outputs, and must make<br />
planning and control decisions based<br />
on faulty information. Berman and<br />
Maloney [79] describe these problems<br />
and their consequences for the oultpatient<br />
departments of teaching hospitals,<br />
and Thompson and Cannon [801<br />
discuss the general benefits and elements<br />
of an improved cost-accounting<br />
system. ?<br />
Conclusions<br />
The future fiscal environment will<br />
provide hospital managers i with<br />
stronger incentives to develop costeffective<br />
PBCP. The elements of such<br />
processes have béen outlined in this<br />
paper and to a large extent represent a<br />
straightforward application of the techniques,<br />
activities, and philosophies<br />
practiced for decades in other sectors of<br />
the economy. The observation that
- 201<br />
Health Services Research<br />
most hospitals need to improve signifi- emerge, the state of practice should<br />
cantly their management control capa- approach the current state of the art.<br />
bilities along these lines appears to This change in management capabilihave<br />
resulted from a perceived lack of ties cannot occur overnight, and pruneed,<br />
followed by a failure to develop dent hospital managers will recognize<br />
and implement-not from significant the time lags associated with such<br />
technical barriers. As the fiscal envi- changes and begin implementation beronment<br />
becomes more hostile, and fore the hea!th care crisis becomes a<br />
as more multiple hospital systems personal problem.<br />
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23. Brown, M. and M. Enright (eds.) Shared services. Topics in Health Care Financing 2(4),<br />
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24. Donabedian, A. Aspects of Medical C"re Administration: Specifying the Requiremenls<br />
for Health Care. Cambridge, MA: Harvard Univ.,rsity Press, 1973.<br />
25. Dunbar, R.L.M. Budgeting for control. Admims",. tive Science Quorterly 16[l):98, Mar.<br />
1971.<br />
26. Klarman, H.E. Application of cost-benefit analysis to the health services and the special<br />
case of technologic innovation. International Journal of Health Services 4(2):325,<br />
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27. Dowling. W.L. Converting Demand Forecasts Into Facility Requirements. In. J.R.<br />
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28. Boardman, J.J. Utilization Data and the Planning Process. In Ann Somers (ed.), The<br />
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29. Griffith, J.R., W.M. Hancock and F.C. Munson. Practical ways to contain hospital costs.<br />
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30. Blue Cross Association. Comprehensive Health Planning: Analytic Techniques.<br />
Chicago: Blue Cross Association, 1974.<br />
31. McClain, J.O. Bed planning using queuing theory, models of hospital occupancy: A<br />
sensitivity analysis. Inquiry 13(2):167, June 1976.<br />
32. Griffith, J.R. Quantitative Techniques for Hospital Planning and Control. Lexington,<br />
MA: Lexington Books, 1972,<br />
33. Thomas, D. and H.H. Stokes. How many beds should a hospital department serve?<br />
Health Services Research 11(3):241, Fall 1976.<br />
34. Conrad, R.B., D.A. Knee, J.M. Meade and LM. Parrish. Utilization study saved hospitals<br />
from needless expansion of radiology facility. Hospital Financial Management<br />
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35. Neumann, J.L. Make overhe.d cuts that last. Harvard Business Review 53(3):116. May-<br />
June 1975.<br />
36. Bennett, J.E. and J. Krasny. Functional value analysis: A technique for reducing hospital<br />
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37. Magerlein, D.B., W.M. Hancock, F.W. Butler, G.W. Mallett and D.R. Young. New systems<br />
can mean real savings. Parts 1 and 2. Hospital Financial Management 32(4):10,<br />
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316. Ann Arbor: Health Administration Press, 1976.<br />
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technique. Harvard Business Review 49(4):45. July-Aug. 1971.<br />
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Hospital Financial Management 29(4):38, 1975.<br />
47. Koza, R.C. Time-series data is essential to health care planning. Hospita! Financial<br />
Management 28(1):32, Jan. 1974.<br />
48. Warner, D.M. Nurse ataffing, scheduling, and reallocation in the ho.-pital. Pospital and<br />
Health Services Administration 21(3):77, Summer 1976.<br />
49. McNally, J.K. How to find manpower levels/lneeds before budgetling. Hospital Financial<br />
Management 30(12):34. De.. t,76d.<br />
50. Kaplan, R.S. Analysis and control t.f aurse staffing. Health Services Research<br />
10(3):278, Fall 197.5.<br />
51. Flynn, J.W. Budgeting salary saving with department head Input. Hospital Financial<br />
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52. Lipson, S.H. and M.D. Hensel. Hospital Manpower Budget Preparation Manual. Ann<br />
Arbor: Health'Administration Press, 1975.<br />
53. Bucldley, A. and E. McKenna. Budgetary control and business behavior. Accounting<br />
and Business Research 2(6):137, Spring 1972.<br />
54. Holmgren, J.H. Purchasing for the Health Care Facility. Springfield. IL: ChaA:Ls sC.<br />
Thomas, 1975.<br />
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Research 10(1):36, Spring 1975.<br />
56. Davis, R.J. Testing the linearity assumption in hospital budgeting and control. Unpublished<br />
Master's thesis, Program in Hospital Administraticon, The University of Michigan,<br />
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57. Pyhrr, P.A. Zero-based budgeting. Harvard Business Review 48(6):111, Nov.-Dec.<br />
1970.<br />
58. Lemer. R.S. and D.E. Willman. Rate setting. Topics in Health Care Financing 1(2),<br />
Winter 1974.<br />
59. Benson, F.S. and M.A. Santullano. Modeling malces budgeting more efficient. Hospitals<br />
50(1):93, Jan. 1, 1976.<br />
60. Lawler, E.E. and J.G. Rhode. Information and Control in Organizations. Pacific Palisad«s,<br />
CA: Goodyear Publishing Company, Inc., 1975.<br />
61. Groner, P.N. Employee incentives. Topics In Health Care Financing 3(3):63, Spring<br />
1977.<br />
62. Austin. C.J. Wage incentive systems: A review. Hospital Progress 51(4):36, Apr. 1970.<br />
63. Williarsn, F.G. And D.C. Anderson. Cost control incentive programs: Appropriate for<br />
non-profit? Hospital Financial Management 32(5):14. May 1978.<br />
64. Davis, S. and J.R Freeman. Hospital managers need management information systems.<br />
Health Care Management Review 1(4):65, Fall 1976.
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Programing, Budgeting. and Control<br />
65. DATAPRO. How to buy software packages. DATAPRO. DATAPRO Research Corp., Jan.<br />
1972.<br />
66. Herkimer, A.G. Improving productivity. Topics in Health Care Financing 4(2). Winter<br />
1977.<br />
67. American Hospital Association. The Management of Hospital Employee Prouucti,'ity:<br />
An Introductory Handbook. Chicago: American Hospital Association, 1973.<br />
68. Moriuchi, M., J.D. Durham and R.D. Roberts. Productivity monitoring: Fi;st step to<br />
effective manpower allocation. Hospital Financial Management 32(S):30, June 1978.<br />
69. American Hospital Association. Dudgeting Procedures for Hospitals, Chap. 9. Chicago:<br />
American Hospital Association, 1¿7'1.<br />
70. Holder, W.W. and J. Williams.: Better cost co.:tral with flexible budgets and variance<br />
analysis. Hospital Financial Management 30(1;.12, Jan. 1976.<br />
71. Flesher, D.L. Operations Auditing in Hospitals. Lexington, MA: Lexington Books, Inc.,<br />
1976.<br />
72. Choate, G.M. Financial ratio analysis. Hospital Progress 55(1):49, Jan. 1974.<br />
73. Bernstein, L.A. Financial Statement Analysis: Theory, Application and Interpretation.<br />
Homewood, IL: Richard D. Irwin, Inc., 1974.<br />
74. Griffith, J.R. Measuring Hospital Performonce. Chicago: Blue Cross Association. 1978.<br />
75. Drebin, M.E. Financial information systems: Key to hospitals' survival, Hospitala<br />
52(12):88, June 16, 1978.<br />
76. Kovener, R.R. Uniform accounting, the background. Hospital Finonciol Monogement<br />
31(6):20, June 1977.<br />
77. Ingram, ).D. Uniform accounting, how it will affect hospitals. Hospital Financial Management<br />
31(6):10, June 1977.<br />
78. American Hospital Association. Chart of Accounts for :I itals. . Chicago: American<br />
Hospital Association, 1976.<br />
79. Berman, R.A. and T.W. Maloney. Are outpatient departments responsible for the fiscal<br />
crisis facing teaching hospitals? The Journal of Ambulatory Care Management 1(1):37,<br />
Jan. 1978.<br />
80. Thompson, G.B. and W.G. Cannon. Hospitals, like industry, must apply cost accounting<br />
techniques. Hospitals 52(12):129, June 16, 1978.
- 205 -<br />
DESIGN <strong>OF</strong> ALTERNATIVE PROVIDER<br />
TEAM CONFIGURATIONS:<br />
EXPERIENCE IN BOTH DEVELOPED<br />
AND DEVELOPING COUNTRIES<br />
by<br />
Dr. Lilia Duran and Dr. Arnold Reisman<br />
Technical Memo 497<br />
ABSTRACT<br />
Job Evaluation, a time-honored industrial engineering<br />
technique developed for manual labor rate-setting was used to<br />
design new personnel resource teams for providing anesthesiology<br />
services in well-known U.S. hospitals on the one hand, and for<br />
delivering primary care in regions of Latin America on the other.<br />
This paper discusses the use of this technique in designing job<br />
descriptions for new allied professionals, and for designing the<br />
curricula necessary to train same. Experience to date in<br />
integrating the products of these curricula into health provider<br />
teams in U.S. tertiary care institutions and in primary care within<br />
several countries of Latin America indicates the soundness of this<br />
approach.<br />
Senior Researcher, Centro Universitario de Tecnologia<br />
Educacional para la Salud (CEUTES), National University of Mexico,<br />
Mexico City.<br />
**<br />
Professor of Operations Research, Case Western Reserve<br />
University, Cleveland, Ohio.
- 206 -<br />
BACKGROUND; THE UNITED STATES<br />
During the last two decades or more, the United States has<br />
been experiencing a shortage of physician-anesthetists relative to<br />
the need for their service [1,2,3]. Many anesthesiology<br />
residencies over the years have gone unfilled as have positions<br />
within hospitals across the country. As late as.1976 it was<br />
reported that 50% of the anesthetics in the U.S. were given by<br />
nurse anesthetists [4]. Parenthetically, this paper will not take<br />
a position as to whether administration of anesthesia ought to be<br />
performed by physician-anesthesiologists or nursc-anesthetists,<br />
both are in short supply. The American Board of Anesthesiology<br />
has reduced the number of i~sidency training programs<br />
significantly, during the last five years. The programs are now<br />
concentrated in major medical centers. Residencies in smaller<br />
peripheral hospitals are few. Yet, the available residency<br />
positions go unfilled.<br />
The shortage of anesthesiologists w.ill probably be influenced<br />
in the future by the following:<br />
These figures have been questioned because there are no data<br />
to establish what proport.ion of these anesthetics were given by<br />
nurses functioning alone as opposed to those supervised by<br />
anesthesiologists [5].
- 207 -<br />
1. A change in the immigration policy for foreign medical<br />
graduates has led to the reduction of the number of foreign<br />
medical graduates available to enter this specialty. In 1972 for<br />
example, 58% of anesthesiologists in formal training programs were<br />
graduates of foreign medical schools [6].<br />
2. The percentage of U. S. medical school graduates entering<br />
anesthesia is decreasing.<br />
3. The anesthesiologists who entered the specialty during<br />
the immediate post-World War II period - a time of the highest<br />
recruitment into the specialty - are now approaching retirement.<br />
Much has been said about physician maldistribution.<br />
Anesthesiologists reflect the same maldistribution. The pronounced<br />
migration out of the snow belt into the southern and western<br />
coastal areas and into the sun belt of the population in general<br />
is reflected also in the movement of anesthesiologists. This<br />
outer-migration further reinforces the problem of anesthesia<br />
coverage in small peripheral hospitals of the North. The small and<br />
peripheral community hospitals have historically experienced the<br />
most difficulty in acquiring anesthesiologists. Of the 7000<br />
hospitals in the U.S., one half have 100 or fewer beds. Of this<br />
latter 3500 hospitals, only 9% have anesthesiologist (MD) coverage<br />
[7]. There is a maldistribution of coverage for obstetrical needs<br />
as opposed to surgical needs [8,9]. Lastly, in situations where<br />
anesthesiologists work alone and without support personnel, it is<br />
fair to assume that they cannot spend the time outside the
- 208 -<br />
operating room to devote their attention to work in the recovery<br />
room, intensive care unit or as- a person who responds to cardiac<br />
arrests or functions as consultant for pulmonary management. The<br />
best use of anesthesiologists would be to have them be involved in<br />
d¿cision-making skills that ¿ae needed from a physician and<br />
delegate the more technical skills to people with lesser training<br />
[i].<br />
Time-sharing of anesthesiologists: the Solution<br />
The use of physician extenders is a rationale reflecting a<br />
national trend to making tho time of physicians available to more<br />
patients by extending their ability to see patients.<br />
Telecommunications technology in medicine or Telemedicine has been<br />
proposed as a solution to problems in medical care during the<br />
1960s [10,11]. Health care professionals in this mode _f iractice<br />
use the telecommunication channels to communicate with each other<br />
or with patients in order to improve the cost-effectiveness and/or<br />
cost benefit of the delivery of health care services. Systems<br />
analysis studies have shown that using either or both the new<br />
communication technologies and different ways to organize the<br />
practice of medicine can result in improving both the quality and<br />
These studies were funded by grants from the U. S. Public<br />
Health Service and from the National Institute of Health.
- 209 -<br />
accessibility of health care delivered while at the same time<br />
reducing the costs of same [12,13].<br />
Two programs to train Physician Assistants in Anesthesia were<br />
developedl based on the perceived need for more non-physician<br />
anesthesia personnel possessing training that is different in kind<br />
from the Nurse Anesthetist. This training, it was thought, should<br />
make the graduates be on a par with a Nurse Anesthetist yet allow<br />
them increased upward mobility with access to professional station<br />
in or outside of medicine. Further, it was hoped that some of the<br />
inter-professional political strains which have traditionally<br />
existed between MD's and RN's would thus be avoided.<br />
It was thought the people drawn into this kind of education<br />
would not commonly be those from the nursing pool. Nursing at the<br />
time of development of the above curricula was experiencing its<br />
own shortage problems. These shortages persist. It was also<br />
thought that the use of a non-physician to extend the contact time<br />
physicians could have with patients would extend their<br />
decision-making qualities to more patients while reducing the<br />
costs of service.<br />
1 Case Western Reserve University in Cleveland, Ohio and Emory<br />
University in Atlanta, Georgia.
- 210 -<br />
Prior to developing the new curriculum, a task analysis was<br />
undertaken in anesthesiology (14]. The study identified all tasks<br />
performed and established which of them could reasonably be<br />
delegated to non-physicians in a manner that would conserve the<br />
anesthesiologist's time yet re-slt in quality patient care and<br />
wider coverage. The determination of which tasks can be<br />
delegated, under what conditions and to whom was made by a group<br />
of qualified anesthesiologists.<br />
The design of the curriculum was obviously an extension of<br />
the results of the task analysis and of the uob Evaluation<br />
Point-Rating System [15,16,17] to be discussed later in this<br />
paper. An assessment of t.h types of activities that<br />
non-physicians could reasonably engage in. resulted in the<br />
curriculum for Anesthesiologists Associates (18].<br />
Lastly, a methodology was developed to cesign optimal<br />
anesthesia team involving Board-qualified MD's and the Anesthesia<br />
Associates. The mix of provider categories was considered in this<br />
methodology to be constrained by budget, personnel availabilities<br />
and the acceptable levels of worker "overloads". The overloads<br />
were used as surrogate measures of the quality of care.<br />
The computer simulation developed to study the efficacy of<br />
alternative team configurations generates a set of daily overload<br />
indicators for different team configurations given some patient<br />
load and mix distribution. The results are plotted on a two
- 211 -<br />
dimensional graph to illustrate the trade-offs between tolerable<br />
overload levels and manpower requirements. These simulation<br />
results provide a basis for manpower mix tradeoffs. An overload<br />
was defined as the unavailability of a given worker within a<br />
5-minute time period to respn¿d to demands for his or her services<br />
because of scheduled or unscheduled commitments to another case.<br />
The three overload categories were further defined as:<br />
(1) Emergency Overload: Number of periods of unsatisfied<br />
emergency calls per day.<br />
(2) Urgent Overload: Number of periods of unsatisfied<br />
induction, early maintenance and<br />
surgical procedure tasks per day.<br />
(3) Routine Overload: Number of periods of unsatisfied tasks<br />
per day.<br />
Experience with the curriculum in both programs at the<br />
Baccalaureate (CWRU) and the Masters level (Emory) indicates that<br />
the content is adequate to train people to function in<br />
anesthesiology at the level of a Nurse Anesthetist. Yet the new<br />
professionals bring more technical or specialized expertise, into<br />
the system. This additional expertise is primarily in respiratory<br />
monitoring and care and in the utilization of more sophisticated<br />
equipment. Acceptance of graduates 'from both programs has been<br />
quite good. Although many graduates have gone on to other kinds of<br />
activities and to graduate study, those who chose to remain in the<br />
profession and work in anesthesia are indeed gainfully employed.
-- 212 -<br />
BACKGROUND; LATIN AMERICA<br />
One of the main problems in primary health care (PHC)<br />
ddlivery systems in Latin-Ar,.erican countries is the lack of<br />
coordination between the providers of PHC services and the<br />
educational institutions engaged in training health personnel<br />
[19-26]. This lack of coordination translates itself into<br />
ill-defined statements about the quantity, quality and mix of<br />
professional resources needed to be trained. The result is an<br />
excess and maldistribution of health personnel in some areas and<br />
almost total absence of personnel in other areas. These<br />
distribution problems are further zomplicated by an accumulation<br />
of tasks at some professional levels while other levels are left<br />
with few tasks to perform.<br />
Task analysis, job and team design, much like in the<br />
Anesthesiology studies, were used as the methodological tools to<br />
generate a data base for use by planners of health services and by<br />
educational ihstitutions. The study developed a methodology<br />
which identifies the professional profiles needed to satisfy the<br />
special conditions of several regions of! Mex-ico.<br />
This study was and continues to be funded 'by the National<br />
University of Mexico and the National Council of Science and<br />
Technology (MEXICO).
- 213 -<br />
Primary Care Health Service System: The Solution<br />
The main objectives of the study were a) to develop a<br />
technique which will allow the definition of the number and kind<br />
of health personnel that ought to be trained; b) to provide a<br />
communication flow, between the training units and the providers<br />
of health care; and c) to establish a feasible way to integrate<br />
curricula for each of the categories of health personnel, thereby<br />
avoiding the proliferation of disorganized actions in providing<br />
health care.<br />
As a point of departure, the study defined a model of the<br />
health service system approach to providing care. It was decided<br />
to work under a model in which the service was more preventive<br />
'<br />
' . .. " , . ,:. . ,: , , , , . , ' i , ',~ ' :i '· , ._:;'.c'3, J _<br />
than curative oriented (19,20,24,25], even though some curative<br />
tasks were included. The model focuses on the delegation of tasks<br />
to primary care and preventive medicine personnel, and on the<br />
design of provider team configurations.<br />
In ordet to do this, it was necessary to establish the<br />
different sequences of health care requiring different levels of<br />
professional skills. These sequences start with self-care, all<br />
tasks performed by the individual to preserve his or his family's<br />
health and end up with a sequence of tasks requiring the highest<br />
professional level. Lastly, the most significant health problems<br />
of Mexico were identified and prioritized. From the above a
- 214 -<br />
matrix (Figure 1) was constructed relating the sequences of care<br />
to the health problems found to be important.<br />
Job Design<br />
Following the methodology delineated in the Anesthesiology<br />
studies [14] modifications of job evaluation techniques were used<br />
to design new job descriptions for health personnel. Using the<br />
downward delegation of tasks principle, the needed health<br />
personnel profiles were thus clearly defined. All tasks that were<br />
actually performed by personnel were identified a.d delegated to<br />
the least expensive and/or least trained professional capable of<br />
performing the task adequately.<br />
According to the scheme shown in Table 1, each box described<br />
the functions that each level of professional has to perform with<br />
respect to each problem in order to maintain and/or preserve a<br />
health outcome. As in anesthesia, this resulted in job profiles<br />
not in existence at the time. This,: an additional. benefit of the<br />
analysis, lead to a more integrated approach to health care<br />
delivery.<br />
Ra.her than going to the field where the tasks were actually<br />
performed as called for by the traditional job evaluation<br />
technique, and as done in the Anesthesia curriculum study, panels<br />
from each of the professional levels in practice at
- 215 -<br />
different health and educational institutions in Mexico were<br />
identified and used in this study. Each panel had a high degree<br />
of expertise in each of the selected health problem areas. The<br />
task assigned to these panels was to fill each of the boxes in the<br />
table. They were asked to write the ideal professional functions<br />
that each level will be performing within the next 10 to 15 years,<br />
and to consider what would be the ideal mix of team<br />
configurations.<br />
As in Anesthesia, this study used the four basic criteria of<br />
job evaluation, namely 1) SKILL, 2) EFFORT, 3) RESPONSIBILITY, 4)<br />
JOB CONDITIONS [15,16,17]. Each of the above factors was in turn<br />
broken down to as many levels as necessary to rate the tasks<br />
necessary for handling each of the selected health problems. The<br />
panels were instrumental in delineating/refining all the factors<br />
and subfactors of this plan. Table 2 - shows the degrees assigned<br />
to each of the subfactors and the description given to each<br />
degree. The panels were able to establish a clear definition for<br />
each of the break points on the scale, avoiding uncertainty and<br />
favoring a more precise rating. The tasks thus delineated and<br />
their ratings with respect to malnutrition, a significant health<br />
problem in Mexico, are presented in Table 3. Currently work is<br />
proceeding in the mental health area, and the same information<br />
will be developed for 25 other major health problems. With all<br />
this information in hand, it will be possible to mix and
- 216 -<br />
interrelate all same-level tasks to each of the health problems.<br />
This procedure will further provide descriptions for new allied<br />
health personnel.<br />
This technique has prco.n useful to assign more adequate<br />
functions to already existing personnel. In Mexico, it has<br />
already defined provider functions for the family planning<br />
program. A continuing education workshop was organized in family<br />
planning for social assistants, social workers, nurse auxiliaries,<br />
registered nurses, general practitioners and gynecologists. The<br />
coverage of this workshop was nationwide, and it included all<br />
major Mexican health institutions.<br />
The first step was to establish what task cught to be<br />
performed by the personnel, irrespective of what they were<br />
actually doing in their respective institutions. Th,'s, the<br />
procedure described earlier was again applied.<br />
With the help of this panel, the tasks that each. personnel<br />
category should realize were defined and rated according to a<br />
number of criteria. Data were then gathered regarding who was<br />
currently performing some of the tasks. A questionnaire was<br />
administered to solicit the panel opinion with respect to the<br />
importance of each task in achieving the objectives of the family<br />
planning program and the frequency of task performance.
- 217 -<br />
The tasks that were rated "very important" and performed on a<br />
daily basis were thus identified and given greater priority.<br />
Based on this study, a course was developed and manuals for<br />
several health personnel categories were developed, including<br />
among others, an instruction manual, student manual, and<br />
actual-practice manual.<br />
The course was developed mainly to teach "multipliers" all<br />
around the country to handle these materials, by performing the<br />
double function of instruction while providing content and method<br />
for the training of other personnel as instructors.<br />
In August 1980, the first workshop including 150 employees of<br />
the Secretary of Health and Welfare from all over the country was<br />
conducted. It has been reported that this workshop had an impact<br />
in improving the performance of the personnel assigned to family<br />
planning programs.<br />
Using this approach, mid-career PHC workers have been trained<br />
for Colombia, Peru, Ecuador, Honduras, Brazil, Bolivia and other<br />
areas of Latin-America. Among these were PHC physicians, nurses,<br />
social workers, etc. Feedback indicates that these procedures are<br />
already being implemented in a number of agencies of family<br />
planning, mental health and other programs within Mexico, Colombia<br />
and Nicaragua. Lastly, the task analysis/job design approach<br />
outlined here has already been incorporated in redesigning<br />
curricula at several universities in Mexico.<br />
12
- 218 -<br />
SUMMARY<br />
This paper indicated how a technique developed for and used<br />
in industrial settings to evaluate manual-job compensation levels<br />
[16,17] was used to design new professional level job categories<br />
for providing more cost-effective health care. Moreover, the same<br />
basic approach was shown to apply in acute care U.S. settings<br />
[14,18] as well as in primary care within developing regions of<br />
Latin America [29,30,31,32].<br />
13
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- 222 -
TABLE 3<br />
TASK ANALYSIS <strong>OF</strong> MALNUTRITION<br />
T TASK A S K I |II | II' ! | i IVI<br />
!<br />
II__________________A _IB _ lt ID_ -a F IG HA I A I D I A 1 1 I B i ICC<br />
- . 1 . . . ~~~~~~~~~~~~<br />
1 1 . . . . . 1 1 . 1~~~~~~~~~~~~~<br />
SELF-CARE<br />
1. Weioht and measure the child periodically.<br />
2. Watch over the child in his daily activities<br />
and educational progress.<br />
_. Assist to the service of well baby care.<br />
4. To provide to the child a balanced diet<br />
prepared hysíenically according to the<br />
family's economic conditions.<br />
5. To promote that the child be engaged in<br />
frequent recreative activities in open<br />
places.<br />
MONITOR<br />
6. Transmite information to organized groups.<br />
7. Realize surveys anc distribute printed<br />
material with informration on malnutrition.<br />
8. Control the ralization of problem's<br />
detection campaigns and their prevention.<br />
9. To differentiate presumtive degrees of<br />
malnutrition.<br />
10. To canalize to specialized treatment the<br />
required cases.<br />
1ST. PR<strong>OF</strong>ESSIONAL LEVEL<br />
11. To carry out lab. examinations.<br />
12. To capacitate monitors.<br />
i3. To supervise monitors.<br />
2ND. PR<strong>OF</strong>ESSIONAL LEVEL<br />
i4. To establish clinic diagnostic of certainty<br />
of malnutrition and degrees of it.<br />
!5. To indicate and to interpret lab. exams.<br />
i16. Soecific trea;ment of the cases.<br />
i.7. Follow directly the evolution of acute<br />
cases.<br />
'S. Recister in total form the cases treated.<br />
19. To interput :reatment resulis.<br />
20. Send to subordinated levels tne cases in<br />
resolution pnase in order So control them.<br />
1<br />
0<br />
0<br />
1<br />
1 1<br />
612<br />
0<br />
0<br />
0<br />
1<br />
2<br />
3<br />
3<br />
3<br />
[3<br />
3<br />
13<br />
3<br />
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111<br />
0 1o 0<br />
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2<br />
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2<br />
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1<br />
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1<br />
1<br />
1<br />
1<br />
1<br />
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2<br />
2<br />
2<br />
2<br />
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312<br />
2<br />
2<br />
2<br />
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1<br />
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2<br />
2<br />
2<br />
312<br />
3<br />
3<br />
- 223 -<br />
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- 224 -<br />
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11<br />
- 225 -<br />
TASK ANALYSIS <strong>OF</strong> MALNUTR TIOj<br />
TAS K J I II IIII IV<br />
A D)EF BC G H IG A CB JC A IB ¡A B 1 C D)E<br />
21. To maintain interchanges of experiences. 5 2 4 2 21 2 3 3 2 2 1 2 1 4 3 3 0 0<br />
of the case with health units related to<br />
the problem.<br />
22. Plan and develop training courses for 7 2 4 3 2 1 2 3 3 2 2 2 2 2 3 3 3 0 O<br />
auxiliar personnel.<br />
3RD. PR<strong>OF</strong>ESSIONAL LEVEL<br />
23. Planning of detection campaigns. 7 2 4 3 2 1 2 3 312 2 2.2 1 4 3 3 0 0<br />
24. To diagnose nutritional deficiences due<br />
to specific factors. 6 2 4 3 2 1 2 3 3 2 3 O 2 1 4 3 O O<br />
25. To prescribe specific treatment.. 6'2 4 3 2 1 2 3 3 2 3 0 2 1 4 3 3 O O0<br />
26. To dq research on malnutrition. 6 2 4 3 2 1 2 3 3 2 3 012 1 4 3 3 O O0<br />
27. To publish papers with respect to research 6 2 4 3 2 1 2 3 3 2 3 1 2 1 4 3 3 O<br />
outcomes.<br />
28. To disseminate research's results. 6 2 4 3 2 1 2 3 3 2 3 1 2 1 4 3 30 0<br />
29. E aborate eoordinate and administer 7 2 4 3 2 1 2 3 3 2 3 22 1 4 3 3 O O0<br />
teaching and service plans.<br />
30. To interchange Interinstitutional 6 2 4 3 2 1 2 3 3 2 3 1 214 3 0<br />
experiences.<br />
1 1 1 1 ~ .<br />
1 1 1 . 1 1 1 !- .<br />
-
- 226 -<br />
REFERENCES<br />
1. Gravenstein, J.S., J.E. Steinhaus, P.P. Volpitto. "Analysis<br />
of Manpower in Anesthesiology," Anesthesiology, 33(3),<br />
September 1970.<br />
2. Gravenstein, J.S., A.Esogbue, A. Reisman, B.V. Dean, V.V.<br />
Aggarwal, V. Kaujalgi, and P. Lewy. "Physician Supply and<br />
Surgical Demand Forecasting: A Regional Manpower Study,"<br />
Management Science, August 1973.<br />
3. Reisman, A., B.V. Dean, A.O. Esogbue, V. Aggarwal, V.<br />
Kaujalgi, P. Lewy, C. deKluyver, J.S. Gravenstein. "Supply<br />
and Demand of Anesthesiologists in Cuyahoga County, Ohio,"<br />
The Ohio State Medical Journal, 69(10), pp. 760-763,<br />
October 1973.<br />
4. Moore, Francis, "Ravenstine Lecture," Anesthesiology<br />
48:125-138, 1978.<br />
5. Ament, Richard, "Anesthesia and Surgical Care: Manpower<br />
Needs and Ultilization," Anesthesiology, 48:88-90, 1978.<br />
6. Orkin, Fred, American Society of Anesthesiologists, 1981<br />
annual meeting, unpublished report.<br />
7. Professional Activities Survey, P.A.S. Ann Arbor Michigan<br />
1978-1980.<br />
8. "National Study of Maternity Care: Survey of Obstetric<br />
Practice and Associated Services in Hospitals in the United<br />
States - 1970," Committee of Maternal Health, American<br />
College of Obstetricians and Gynecologists, 1970.<br />
9. Rasmussen, J., T. George, A. Reisman, W. Cull, J.;S.<br />
Gravenstein, "Obstetrical Anesthesiology Practice and<br />
Attitudes in Cuyahoga County, Ohio Hospitals: A Survey,"<br />
The Ohio State Medical Journal, Vol. 73, pp. 139-144.<br />
10. Bashshur, R.L., Armstrong, P.A., Youssef, Z.I. Telemedicine:<br />
Explorations in the Use of Telecommunications in Health<br />
Care. Springfield, Charles C. Thomas, 1975.<br />
11. Gravenstein, J.S., B. Grundy, Y. Pao, A. Reisman, F. Staub,<br />
"The Cleveland Telemedicine Project," Telecommunications<br />
For Civic And Social Services, No. 20, 1976 Wescon<br />
Professional Program Proceedings, Los Angeles, pp. 1-2,<br />
September 1976.
- 227 -<br />
12. Reisman, A., F.Staub, B.V. Dean, J.S. Gravenstein, V.<br />
Aggarwal, V. Kaujalgi, C. deKluyver. "Anesthesiology<br />
Manpower Planning Study Phase III - Progress Report I,"<br />
Technical Memorandum No. 280, Department of Operations<br />
Research, Case Western Reserve University, December 1972.<br />
13. Reisman, A., W. Cull, H. Emmons, B. Dean, C. Lin, J.<br />
Rasmussen, P. Darukhanavala, T. George, "On the Design of<br />
Alternative Obstetric Anesthesia Team Configurations,"<br />
Management Science, Vol 23, No. 6, February, 1977.<br />
14. Reisman, A., B.V. Dean, V. Kaujalgi, V. Aggarwal,.P. Lewy,<br />
J.S. Gravenstein. "A Task Analysis in a Clinical Specialty<br />
Providing Data for a New Curriculum for Anesthesia<br />
Personnel," Socio-Economic Planning Sciences, Vol. 7,<br />
pp. 371-379, 1973.<br />
15. Job Evaluation Plan, American Institute of Industrial<br />
Management.<br />
16. Lanham, E., Job Evaluation. McGraw-Hill, New York, 1955.<br />
17. Lytle, C.W., Job Evaluation Methods. Ronald Press, New York,<br />
1954.<br />
18. Gravenstein, J.S., and M. F. Rhoton. "Teaching Anesthesia to<br />
Undergraduate College Students," Anesthesiology, 37(6),<br />
641-646, 1972.<br />
19. Arango, Jaime "Planeacion Curricular y Evaluacion en Funcion<br />
de las Necesidades de un Pais," Educacion Medica y Salud,<br />
6, 3 y 4, 1972.<br />
20. Butler, Willis, "The Undergraduate Education of Physicians in<br />
Cuba," Journal of Medical Education, Vol. 48, September,<br />
1973.<br />
21. Galvao Lobo, Luiz Carlos, "O Uso de Nova Tecnologia<br />
Educacional no Formacao de Recursos Humanos," Educacion<br />
Medica y Salud, 8, 2, 1974.<br />
22. Gutierrez, Rodrigo, "Participacion de la Universidad en la<br />
Planificacion de la Salud," Educacion Medica y Salud,<br />
7,3-4, 1978.<br />
23 Hutchins, Edwin B. y Hoack, Horst, "Evaluacion de los<br />
Programas de las Escuelas de Medicina," Educacion Medica y<br />
Salud, 4. 4. 1970.<br />
24. Duran, Lilia, "An Alternative Way of Curriculum Planning in<br />
the Health Sciences." Conference presented at the<br />
International Coloquium of Education, National University<br />
of Mexico, October, 1979.
- 228 -<br />
25. Duran, Lilia, "Desarrollo de una Metodologia para Establecer<br />
Prioridades de Atencion en el Sector Salud." Internal<br />
working paper, Centro Universitario de Tecnologia<br />
Educacional para la Salud (CEUTES) , June, 1981.25.<br />
26. LaSalle, Gerald, "Nuevos Modelos en la Formacion Profesional<br />
del Personal de la Salud," Universidad de Sherbrooke,<br />
Educacion Medica y Salud, 4, 4, 1970.<br />
27. Maddison, D.C. "What's Wrong with Medical Education?" Medical<br />
Education. 1978, 12, pp. 97-102.<br />
28. Rexed, Bror, "The Role of Medical Education in Planning. The<br />
Development of a National Health Care System," Journal of<br />
Medical Education, Vol. 49, January 1974.<br />
29. Duran, Lilia, "Una Aplicacion de la Tecnica de Analisis de<br />
Tareas a Partir de un Modelo de Servicio en el Area de la<br />
Salud y su Derivacion en Objetivos Generals de Carrera."<br />
Technical Report. Centro Latinoamericano de Tecnologia<br />
Educacional para la Salud (CLATES), 1979.<br />
30. Duran, Lilia y Torres, A., "Planificacion Familiar: Una<br />
Aplicacion de la Tecnica de Analisis de Tareas." Technical<br />
Report. Centro Latinoamericano de Tecnologia Educacional<br />
para la Salud (CLATES), 1979.<br />
31. Duran, Lilia, "Algunas Sugerencias de Apoyo al Catalogo<br />
Nacional de Ocupaciones en el Area de Planeamiento<br />
Curricular." Documento Presentado a la Direccion General<br />
de Planeacion de la S.E.P. (Secretary of Public Education)<br />
Marzo, 1980.<br />
32. Duran, Lilia, "Technology Development for a Quantitative and<br />
Qualitative Definition of Human Resourcres in the Health<br />
Field." Research proposal submitted to the National<br />
Council of Science and Technology, June, 1979.
- 229 -<br />
METHODS<br />
Parameters Affecting Hospital Occupancy<br />
and Implications for Facility Sizing<br />
By Walton M. Hancock, David B. Magerlein, Robert H. Siorer, and<br />
lames B. Martin<br />
Simulation is used to investigate the effects on hospital occupancy of the<br />
number of beds in the facility, the percentage of patients who are emergencies,<br />
the percentage of elective patienta who are acheduled, and the average<br />
lengths of stay of emergency and elective patients. A practical method is<br />
presented for estimating the optimum suze of a short-term hospital on the<br />
basis of expected demand, and use of the resulta in planning is discussed.<br />
To operate at minimum cost it is imperative that a hospital not<br />
contain more beds than necessary to meet demand. The nontrivial<br />
costs of building, stafflag, and maintaining unused beds are unnecessary<br />
and are ultimately bdrne by the health care consumer. The variable<br />
cost of staffing and maintaining a hospital bed was found to be<br />
$10,130 per year in one study [1] and $16,201 per year in another [2],<br />
and the fixed cost of building a bed has been quoted as $50,000 [3].<br />
Thus, considerable savings are possible by eliminating beds in an<br />
overbedded Hospital (saving variable costs) and by preventing the construction<br />
of unneeded beds (saving both fixed and variable costs).<br />
A simulation-based analysis of the effects of several parameters<br />
on hospital occupancy is presented. The parameters investigated are<br />
number of beds in the facility, percentage of patients who are emergencies,<br />
percentage of elective patients whose admission date is set in<br />
advance (scheduled patients), and mean lengths of stay of emergency<br />
and elective patients. A practical method is developed for predicting<br />
the correct size of hospital facilities, given the expected demand. Current<br />
planning methods such as the Hill-Burton formula, the Poisson<br />
assumption, and that of Shonick [4] are shown to be inappropriate<br />
ThiJ study was supported by PHS grant no. HS00228 from ¿he National Center<br />
for HIalth Services Rescarch (DHEW) and by the W.K. Kellogg Foundation<br />
through the Greater Detroit Arca Hospital Council, Inc.<br />
Addrdeu communications and requests for reprints to Walton M. Hancock,<br />
HEALTH ProCessor of Induswlrial and Operations Engineering and Hospital Administration,<br />
SERVICES Program and Bureau of Hospital Administration, University oJ Michigan School of<br />
RESEARCH Public Health, 1420 Washington Heights, Ann Arbor, MI 48109. David P. Mager.<br />
ARC. A'I cin is a graduate student and Robert H. Storr is an undergraduate student, both<br />
in industrial and operations engineering; and ]ames B. Martin is assistant professor<br />
of hospital adminisuration. All of the authors are at the University of Michigan.<br />
0017-9124/78/03027614/$02.00/0<br />
( 1978 Hospital Research and Educational Trust
- 230 -<br />
since they substantially overestimate the necessary number of beds in SIMULATION<br />
most cases. <strong>OF</strong> HOSPITAL<br />
OCCUPANCY<br />
Simulation Model<br />
The Admissions Scheduling and Control System<br />
In order to model and simulate a hospital, specific rules, policies,<br />
and priorities regarding patient admissions must be defined. The<br />
admissions -guidelines of the Admissions Sclieduling and Control System<br />
(ASCS) developed by Hancock et al. [51 are used in this model.<br />
Simulation studies have predicted that hospitals using this system<br />
would operate at occupancies in excess of those found in most hospitals,<br />
and implementation of the ASCS in several hospitals has shown<br />
these predictions to be realistic [6,7]. A facility using the ASCS should<br />
require fewer beds to meet demand and thus should operate at a lower<br />
cost. A model using the ASCS should predict the optimum number<br />
of beds needed to operate a hospital.<br />
In the ASCS, admissions to the hospital are classified in three<br />
categories: emergency, scheduled, and call-in. An emergency patient is<br />
defined as one requiring immediate admission to the hospital. Thus<br />
an emergency admission is uncontrollable and may be considered a<br />
random event. Scheduled and call-in patients are elective and thus do<br />
not require'immediate admission; they may be put on a v.aiting list<br />
or scheduled for admission at some future date. The admission of a<br />
scheduled patient is planned for a specific time-in the future, and a<br />
call-in patient is called in for admission at the hospital's convenience.<br />
Thus, if at some time during the day the hospital has beds available,<br />
patients are called in.<br />
A turnaway is defined as an emergency patient who cannot be<br />
accommodated in the normal manner because all hospital beds are<br />
full. A cancellation is defined as a scheduled admission that must<br />
be cancelled in order to save room for emergency patients who may<br />
arrive before the next day's discharges. Thus a scheduled admission<br />
is cancelled in order to prevent the possibility of an emergency turnaway<br />
later in the day. In practice, cancelled patients are rescheduled<br />
at the next open date or are called in with the highest priority. In<br />
this study, turnaways were constrained to be between 1 and S percent<br />
of all emergency arrivals and cancellations were constrained to be<br />
between 1 and 3 percent of all scheduled admissions. These percentages<br />
were chosen because they appeared to be acceptable to the hospitals<br />
that had become aware of the ASCS.<br />
At some point during the day when all discharges are known, the<br />
hospital must decide if it is necessary to call in patients or to cancel<br />
any scheduled admissions. This decision is based on the census reduction<br />
allowance (CRA) and the cancellation allowance (CA). The CRA<br />
and the CA represent the upper and lower bounds on the number of<br />
beds left empty at the decision point and may be different for each<br />
day ,. e week. The number of filled beds includes those to be occupied<br />
by patients scheduled for admission later in the day. If the number<br />
of empty beds is g_ eter than the CRA, patients are called in until
- 231 -<br />
~HNCOCK Fig. 1. Daily census with and without call-ins.<br />
ET AL<br />
Without Coll-in$-<br />
45 - Census Mean , 172.63<br />
Census Standard Devioation · 11.459<br />
40 - With Co'l-ins<br />
Census Mean*187.85<br />
35 - Census Standard DeviQtion 5.956<br />
25 -<br />
z II,<br />
120o<br />
¡40 'N45 150 ¡55 160 .t65 170 175 180 185 190 195 200<br />
CENSUS<br />
the number of empty beds equals the CRA. If the number of empty<br />
beds is less than the CA, scheduled admissions are cancelled until the<br />
number of empty beds equals the CA. Thus the census at the decision<br />
point is always between the CRA and the CA. The overall effect<br />
of these allowances is to reduce significantly the variance in the hospital<br />
census and thus increase the attainable occupancy while maintaining<br />
a given turnaway level.<br />
Reduction of census variance through use of the call-in algorithm<br />
is the mechanism that allows the ASCS to achieve high average occupancies.<br />
This census variance reduction is illustrated in Fig. 1, which<br />
shows two separate simulation runs in which the numbers of scheduled<br />
and emergency patients admitted are equal. It is apparent that a<br />
facility using the call-in algorithm will operate at a higher average<br />
occupancy and with lower census variance than a unit without callins.<br />
In addition, a facility using the call-in algorithm will be at its<br />
bed capacity (200 beds in Fig. 1) much more often than a facility without<br />
call-ins.<br />
Probability Distributions of Emergency Arrivals<br />
and Patient Lengths of Stay<br />
In order to simulate the randomness of a hospital, it is necessary<br />
to assign a probability density function to emergency arrivals and to<br />
patient length of stay. The Poisson distribution is used here to model<br />
HEALTH emergency arrivals. This has been done often and has been found to<br />
E VEICRS be a good fit to empirical daily emergency arrival distributions [8,9]<br />
as well as being theoretically appealing. In the simulation model, a<br />
day is divided into two periods. The first period extends from the
- 232 -<br />
time when discharges begin to the time when all discharges are known<br />
(the decision point). The second period extends from the decision<br />
point to the time when the next day's discharges begin. For simplicity,<br />
it is assumed that the distributions of emergency arrivals in each period<br />
are identical. The assumption should have little effect on the<br />
results. The percentage of emergency arrivals, a variable closely allied<br />
to the overall mean emergency arrival rate, is one of the parameters<br />
whose effects are investigated in this study.<br />
Assigning a probability distribution to inpatient length of stay<br />
(LOS) is difficult. The nature of these distributions varies greatly<br />
among hospitals, services, and days. Some researchers have used negative<br />
exponential, lognormal, and gamma distributions to model LOS<br />
[7,8,9). Others report that no distribution fits their LOS data [7]. One<br />
possibility is to use an empirical distribution from a specific hospital,<br />
but that idea is discarded here in an effort to keep the model as generally<br />
applicable as possible. The use of a distribution described by<br />
a mathematical function makes it easy to produce probability density<br />
functions with given means and variances. This in turn allows LOS<br />
to be varied as a parameter.<br />
To model LOS, the lognormal distribution, which has been found<br />
to be a good approximation to empirical LOS distributions, is used<br />
[10]. To justify its use, 140 LOS distributions*-om five different hos.<br />
pitals were examined. The use of the lognormal distribution appeared<br />
to be reasonable, and it was concluded that a variance of about<br />
seven times the mean is a good approximation. In this study, mean<br />
LOS is assumed to be somewhat higher for emergency patients than<br />
for elective patients.<br />
Because of computer capacity restrictions, the LOS distributions<br />
were truncated at 50 days within the simulation, but this had little or<br />
no effect on the results because the LOS distributions had low frequencies<br />
at 50 days. (All means and variances refer to the truncated<br />
distributions.)<br />
Simulation Runs<br />
As stated previously, the effects of several parameters on the maximum<br />
average occupancy of a facility were examined. Maximum aver.<br />
age occupancy is the highest average occupancy that can be achieved<br />
by searching for the best choices of the CRA and CA for each day of<br />
the week. Initially, the following paramaters were investigated: number<br />
of beds, percent of emergency admissions (percent EMG), and percent<br />
of elective patients scheduled.<br />
During the first phase of the study, patients were scheduled five<br />
days a week (to reflect the scheduling policy of most hospitals) and<br />
emergency and elective LOS means were 10.38 and 8.39 days, respectively.<br />
These lengths of stay are typical of those found in midwestern<br />
general hospitals.<br />
The number of beds was varied over 40, 80, 120, 160, and 200. At<br />
each level the percent emergencies and percent scheduled were varied<br />
as shown in Table 1 (p. 280).<br />
SIMULATION<br />
<strong>OF</strong> HOSPITAL<br />
OCCUPANCY<br />
FALL<br />
1978
- 233 -<br />
HANCOCK Table 1. Parameters Varied for Simulation of<br />
ET AL<br />
Hospital with Five-Day Scheduling to Determine<br />
Maximum Average Occupancy at 40, 80, 120,<br />
160, and 200 Beds<br />
Phase 2<br />
Phase I<br />
E1%~'~ % ~<br />
EMfG scheduled<br />
Mean<br />
emeremnc<br />
LOS<br />
Mean<br />
elecotuve<br />
LOS<br />
acheduled<br />
30 40, 70, 90 5.1 43 40, 70. 90<br />
50 40,70,90 10.4 8.4 40,70.90<br />
66 40,70.90 14.9 13.1 40,70.90<br />
95 0<br />
In the second phase of the study, the effects of mean LOS on maximum<br />
average occupancy were investigated. Percent EMG was held<br />
constant at 50 percent and patients were scheduled five days a week.<br />
Again, the number of beds was varied over the same five levels. Within<br />
each level, mean LOS and percent scheduled were also varied as shown<br />
in Table 1.<br />
In the third part of the study, the effect of scheduling seven days<br />
a week rather than five was investigated. Percent EMG was held constant<br />
at 50 percent and the emergency and elective LOS means were<br />
10.38 and 8.39 days, respectively. The number of beds was again varied<br />
over 40, 80, 120, 160, and 200, and percent scheduled was varied<br />
over 40, 70, and 90 percent.<br />
A Fortran simulation program developed by Hamilton, Hancock,<br />
and Hawley [11] was used. This program embodies the rules of the<br />
ASCS and allows much flexibility in modeling different hospital and<br />
facility settings. The simulator has been documented and validated<br />
[5,11], but an attempt was made here to estimate the magnitude of<br />
possible errors involved in the simulation process.<br />
The parameters percent emergencies and percent scheduled are<br />
not directly controllable through the input but are dependent on the<br />
number of call-ins that occur. Thus a search procedure is involved in<br />
which the inputs are varied until the proper levels of the parameters<br />
are approximated and the turnaway and cancellation constraints are<br />
satisfied. Once this is accomplished, the allowances are varied until<br />
the maximum average occupancy at the given parameter levels is<br />
determined. This procedure causes two possible sources of error.<br />
It is impossible to set all of the parameters exactly at the specified<br />
levels. Percent emergencies and percent scheduled are generally<br />
within -2 percent of the assigned level, and the error that this induces<br />
in maximum average occupancy may be estimated from the<br />
HEALTH results using linear interpolation. For example, Fig. 2b shows that in<br />
XUEACI<br />
K a facility with 40 beds. a change of 30 percent in percent scheduled<br />
results in a change of 6.5 percent in maximum average occupancy.<br />
Thus an error of 2 percent in percent scheduled would cause an error
- 234 -<br />
Fig 2. Maximum average occupancy vs. number of beds for different percentages<br />
of emergency arrivals and with 40, 70, and 90 percent of electives scheduled.<br />
4-<br />
c<br />
Q)<br />
o,<br />
8 0<br />
w<br />
(Z<br />
ir<br />
2<br />
2<br />
00ooE<br />
95<br />
90<br />
85,<br />
100 r-<br />
- 30%EMG<br />
-50% EMG<br />
- 66% EMG<br />
(a)<br />
i .... 1 i .... 1.,. ... i .. 1<br />
I. 1 * . . ...<br />
........... ......... . ..<br />
951-<br />
90<br />
30% EMG<br />
50% EMG<br />
85 -66% EMG<br />
A .1<br />
l u<br />
100 r<br />
95 ..<br />
90<br />
50% EMG<br />
85 -66% EMG<br />
30% EMG<br />
Oo.<br />
40% of the Electives are Scheduled<br />
I .<br />
(b)<br />
1 , .... l . ., .e i . 1 e 1 . IIa<br />
- - - - - - - - - - - - - - -<br />
70% of the Electives are Scheduled<br />
cele 1 e1 IIo le! e ej le m te<br />
50 75 t00 125 150<br />
NUMBER <strong>OF</strong> BEDS<br />
90% of the Electives are Scheduled<br />
(c)<br />
1 1 I le L í<br />
175 200 .
- 235 -<br />
Fig. 3. Maximum average occupancy vs number of beds for different<br />
percentages of scheduled arrivals and with 30, 50, and 66 percent<br />
emergency arrivahs.<br />
100 r<br />
95<br />
90<br />
85<br />
- A<br />
c lw<br />
o<br />
g 95 -<br />
uo<br />
o<br />
90 _<br />
o 85 -<br />
, < r_<br />
95 -<br />
40% 0SCH<br />
l90% SCH<br />
' f . lilit 1 i I I1 i"<br />
40%SCH<br />
90- 40% SCH>/<br />
70%SC<br />
85 9 0 %SC'<br />
Ot '- '550<br />
(a)<br />
1 I tf I 3 I m 1I 1 ¡ t ¡ t i<br />
30% of the Arrivalis ore Emergencies<br />
50% of the Arrivais are Emergencies<br />
66O,<br />
(b)<br />
(c)<br />
1 1 1<br />
75<br />
le iI i 1 1 1 i lb i i ¡te i<br />
100 125 150<br />
NUMBER <strong>OF</strong> BEDS<br />
i I i i i i I<br />
175 200<br />
YO of the Arrivas 'are Emergencies
- 236 -<br />
of (0.02 x 0.065/0.30) x 100 = 0.43% in maximum average occupancy. SIMULATION<br />
<strong>OF</strong> HOSPITAL<br />
Similarly, for percent EMG (Fig. 3b, 40 beds), an error of 2 percent in OCCUPANCY<br />
percent emergency would cause the following error in maximum<br />
average occupancy for the 30 and 50 percent emergency levels:<br />
(0.02 x (0.937 - 0.897)/0.20) x 100 = 0.40%<br />
These figures represent the maximum errors in occupancy. In general<br />
(at different parameter levels) the error will be much smaller because<br />
the differences in the numerator are smaller. The possible errors are<br />
easily calculated from the graphs for an individual case. (It is interesting<br />
that the error increases as the number of beds decreases.)<br />
As with any simulation, there is a certain variability in results<br />
due to pseudorandom generation of numbers. In order to estimate<br />
the variance in occupancy within the simulation, 20 100-week runs<br />
were performed with identical inputs but with different seeds for the<br />
random number generators. The sample standard deviation in mean<br />
percent occupancy between runs was found to be 0.033 percent.<br />
It is possible to estimate the total error in predicted maximum<br />
average occupancy due to the simulation. Assuming that the error<br />
due to pseudorandom number generation is normally distributed<br />
and using a 99-percent confidence interval, the maximum error in<br />
occupancy (percent) is<br />
2.58 x (o-EM 2 + arEL 2 + 'RNp2) X 100<br />
where oE, = the standard deviation of the error due to variation<br />
in percent emergency. The maximum error is already<br />
computed as 0.43 percent. Assuming thie error to be<br />
normally distributed and using 99-percent confidence<br />
intervals<br />
YO -EM 0.43/(2.58 x 100) = 0.00167<br />
oEL = the standard deviation due to variation in percent electives.<br />
The maximum error is computed as 0.40 electives.<br />
Using the same assumptions'as for o'Em<br />
EZL f 0.40/(2.58 X 100) --'0.00155<br />
CraN = the standard deviation due to pseudorandom number<br />
generation. This has previously been found to be<br />
0.00033. Therefore, maximum error in occupancy =<br />
±2.58 x (0.001672 + 0.001552 + 0.000332)J x 100 = +0.594<br />
percent occupancy. This figure, ±0.594 percent occupancy,<br />
is an estimate of the maximum error due to the<br />
sources discussed above.<br />
Restu. . FALL.<br />
1978<br />
The results of the procedures outlined are shown in Figs. 2-5,<br />
and the effects of the different parameters on occupancy are discussed
- 237 -<br />
HANCOCK<br />
ET AL Fig. 4. Maximum average occupancy vs. number<br />
of beds with 95 percent emergency arrivals and<br />
all electives called in.<br />
o95<br />
100oo<br />
90<br />
85<br />
0% CH<br />
0 50 75 o00 125 150 175 200<br />
NUMBER <strong>OF</strong> BEDS<br />
below. Perhaps it would be desirable to use Fig. 4. as a benchmark<br />
when examining the remaining figures since it is closest to the historical<br />
Poisson arrival process.<br />
In all cases, maximum average occupancy increases with increasing<br />
facility capacity. The higher percent occupancy in larger facilities<br />
results from a decreasing coefficient of variation of census (standard<br />
deviation/mean) as the number of beds increases. When the coefficient<br />
of variation is small, the maximum average mean census may be<br />
doser to the facility-capacity while still maintaining the turnaway<br />
and cancellation constraints.<br />
For a given number of beds maximum average occupancy is observed<br />
to increase with decreasing percent scheduled. This is a result<br />
of the fact that as percent scheduled decreases, the number of call-ins<br />
is increased. Thus the ability of call-ins to reduce census variance is<br />
improved as percent scheduled decreases.<br />
In this study when patients are scheduled five days a week, a lack<br />
of call-ins is felt most heavily on weekends. With no patients scheduled<br />
for Friday and Saturday, it is necessary to call patients in to<br />
maintain a high maximum average occupancy. If the call-ins are<br />
unavailable due to a high percent scheduled, a weekend drop-off in<br />
average occupancy occurs. (Remember that the ratio of call-ins to<br />
scheduled patients is constant.)<br />
In most cases, maximum average occupancy is observed to increase<br />
as percent EMG decreases. This is because, in general, emergency<br />
arrivals introduce a greater variance in the census than elective arrivals.<br />
In certain cases, however, this is not true. In this study, when<br />
percent scheduled is 90 percent, the variance in census caused by elective<br />
admissions is larger due to the drastic weekend drop-off in averlHELTH<br />
age census. Thus, when percent scheduled is high and patients are<br />
ReIEARCH scheduled five days a week, maximum average occupancy will decrease<br />
as percent EMG decreases and the percent of elective patients<br />
increases.
- 238 -<br />
Fig. 5. Maximum average occupancy vs. number of beds with 50 percent emergency<br />
arrivais and 40, 70, and 90 percent of electives scheduled. Results of model are<br />
compared with Hill-Burton formula and Poisson model in (c).<br />
c<br />
Q>
- 239 -<br />
AECOCL. Table 2. Eflect of Changc in Schedulcd<br />
Caincellation (SC) and Emergency Turnaway (ET)<br />
Rates on Maximum Average Occupancy<br />
Maximum average Average no.<br />
No. of o/<<br />
bds<br />
beds EMG<br />
%<br />
sched.uled<br />
occupancy SC + ET for<br />
1-3% con<br />
SC and SC and<br />
ET: 1-3% ET: 2/mo tra<br />
320 30 30 99.3 98.7 8.3<br />
320 30 90 94.6 90.6 25.6<br />
320 90 90 96.1 90. 21.9<br />
80 30 30 97.6 96.5 3.2<br />
80 30 90 90.7 87.3 5.4<br />
80 90 30 90.8 85.0 4.7<br />
*Fewer than two per month but as close to tw as posible.<br />
In general, if percent scheduled is below a certain level (approximately<br />
80-90 percent) or if patients are scheduled seven days a week,<br />
maximum average occupancy will increase as percent EMG dqcreases.<br />
It is advantageous (from a maximum average occupancy standpoint)<br />
to schedule seven days a week because no weekend drop-off<br />
then occurs. Figure 5a shows that when percent scheduled is high, the<br />
use of seven-day scheduling allows a higher maximum average occupancy<br />
than does the use of five-day scheduling. This is to be expected<br />
since the'weekend drop.off for five-day scheduling has a greater effect<br />
when percent scheduled is high. Thus, when sizing a facility it is necessary<br />
to be aware of how patients are to be scheduled.<br />
The results of varying mean LOS are shown in Fig. 5b, where it<br />
can be seen that mean LOS has a much smaller effect on maximum<br />
average occupancy than the other parameters do. In sizing larger<br />
facilities, the mean LOS will have little effect on the results, but the<br />
same cannot be said for small facilities (fewer than 40 beds).<br />
As mentioned previously, the maximum average occupancy is affected<br />
by percent cancellations and turnaways. In Table 2 the maximum<br />
average occupancy with the 1-3 percent constraint on cancellations<br />
and turnaways is compared with the maximum average occupancy<br />
with the sum of the cancellations and turnaways being less than<br />
but as close as possible to 2 per month. For 320 and 80 beds, the constraint<br />
change results in a decrease in the cancellations and turnaways<br />
and the maximum average occupancy also decreases. For comparison,<br />
the sum of cancellations and turnaways for the 1-3 percent constraint<br />
is also given in average occurrences per month. For purposes of<br />
planning or determining the number of beds needed, the scheduledcancellation<br />
and emergency.-turnaway rates should be viewed as a<br />
HEALTH matter of policy. Once agreement is reached on their acceptable level,<br />
LSEAR' CH lthen maximum average occupancies can be computed using the simulator.<br />
It should be noted here that the occupancy data for 320 beds<br />
are not strictly part of this research and are furnished only for their
- 240 -<br />
vallie in thc sensitivity analysis of the cancellation and turnaway SIMULATION<br />
constraint. <strong>OF</strong> HOSPITAL<br />
OCCUPANCY<br />
Application of Results in Facility Sizing<br />
-The results of this study may be applied in determining the correct<br />
size of a hospital. The method is as follows.<br />
A. Obtain an estimate of the average daily census (ADC) of the<br />
facility. For planning purposes, this is frequently obtained by<br />
taking the present ADC and adjusting for demographic factors<br />
over thc planning horizon.<br />
B. Estimate the parameters for the facility (percent EMG, percent<br />
scheduled, mean LOS, and scheduling pattern). The usual<br />
assumption is that the percentages will not change over the planning<br />
horizon.<br />
C. Find the graph in Figs. 2-5 that is closest to the parameters<br />
estimated in B above.<br />
D. Determine the necessary number of beds (NB) using successive<br />
approximations as follows.<br />
1. Use ADC as an initial estimate of the number of beds, and<br />
determine a percent occupancy from the appropriate graph.<br />
2. Determine the number of beds needed using NB = ADC/<br />
(% occupancy/100).<br />
3. Use the number of beds found in step 2 to determine a<br />
revised percent occupancy.<br />
4. Return to step 2 and compute a new NB using the revised<br />
occupancy of step 3.<br />
5. Repeat steps 2, S, and 4 until the bed-number estimates<br />
converge.<br />
Use of the algorithm described above assumes, of course, that the<br />
ASCS system will be used to admit patients to the facility. The specific<br />
schedules, CRA and CA, which are specific for day of the week,<br />
can be quickly obtained using the admissions simulator. These values,<br />
of course, will vary for any point on the particular curve used.<br />
As an example, consider a facility with average daily census =<br />
180.0, percent EMG = 66, and percent scheduled = 70. To determine<br />
the optimal number of beds, find the occupancy estimate Of 96.3 percent<br />
from Fig. 2b using number of beds = 180. Then,<br />
NB = 180.0/(96.3/100) = 186.9<br />
This rounds to 187 beds. Figure 2b gives the occupancy estimate of<br />
96.5 percent for 187 beds. Thus the second estimate of beds is<br />
NB = 180.0/(96.5/100) = 186.5<br />
This again rounds upward to 187 beds, the sequence has converged,<br />
and the optimal number of beds of such a facility is 187.<br />
The results of this study should not be extrapolated to small<br />
(fewer than 40 beds) facilities, which should be simulated individually<br />
sinc. percent occupancy is extremely sensitive to the number of beds<br />
in the facility.
- 241 -<br />
HANCOCK Discussion<br />
ET AL These results ma> be used to determine occupancy factors for<br />
bed-planning methods. In comparison, other current planning methods,<br />
such as that of Shonick [4], the Hill.-Burton formula, and the<br />
Poisson sizing assumption, overestimate the number of beds needed in<br />
most cases and are thus inappropriate. Shonick's methodology is the<br />
same as the one in this study, but his model is different, and his results<br />
cannot be put in the format used here. The lack of a call-in algorithm<br />
as a census restorer will cause Shonick's method to have substantially<br />
lower maximum average occupancies under identical cancellation and<br />
turnaway constraints.<br />
In Fig. 5c the results of the present study are compared with the<br />
Hill-Burton formula, the Poisson assumptions, and the results obtained<br />
by Hancock, Martin, and Storer [12], who used a similar but<br />
less extensive approach. It is apparent that facilities can operate at<br />
occupancies much higher than those predicted by Shonick, the Poisson<br />
asssumptions, and the Hill-Burton formula. The exceptions occur<br />
in cases where percent scheduled is high and the number of beds is<br />
less than 75. In these cases the Hill-Burton formula predicts a somewhat<br />
higher occupancy than is possible. Both the Hill-Burton and<br />
Poisson modeis ignore important facility parameters that determine<br />
maximum average occupancy.<br />
Figure 5c shows that the occupancy curve derived by Hancock<br />
falls in the same range as the results of this study, but its different<br />
shape is attributable to the fact that Hancock used different turnaway<br />
and cancellation constraints. His constraints were set at two cancellations<br />
and two turnaways per month. Thus, in small facilities, two<br />
per month represents a large percentage of arrivals, whereas in larger<br />
faciliiies the percentage becomes smaller. This explains the "flatness"<br />
of the curve derived by Hancock and also serves to point up the<br />
sensitivity of the turnaway and cancellation constraints mentioned<br />
earlier.<br />
When sizing hospital facilities, all important parameters and characteristics<br />
of these facilities must be evaluated. All parameters must<br />
be consiaered collectively since their effects on occupancy are not independent.<br />
The results of this study may be applied to the sizing of<br />
individual facilities although it is important that factors not dealt<br />
with in this paper also be taken into account. Specifically, if the turnaway<br />
and cancellation constraints differ from those used here, one<br />
must expect the occupancy to differ as well. Other factors such as<br />
scheduling pattern, seasonal variations that cannot be smoothed by<br />
admission scheduling, and (to a lesser extent) mean lengths of stay<br />
should also be considered.<br />
REFERENCES<br />
1. Magerlein. D.B., W.M. Hancock, F.W. Butier, G.M. Mallett. and D.R. Young.<br />
HEALTH New systems an mean real savings. Hosp Financ Manage 32:10 Apr 1978 and<br />
SERVICES 32:18 May 1978.<br />
RESER.CH 2. Magerlein. D.B.., R.J. Davis, and W.M. Hancock. The Prediction of Departmental<br />
Activity and Itr Use in the Budgeting Proceus. Report No. 76-1. Bureau of<br />
Hospital Administration. University of Michigan, Dec. 1976.
- 242 -<br />
S. Facilities Engincering and Construction Agency. DHEW. Representative Construction<br />
Costs o1 Hojpitals and Related Health Facilities, p. iv. DHEW Pub.<br />
No. (OS) 73-6. Washington, DC: US. Government Printing Office, 1972.<br />
4. Shonick, W. Understanding the nature of random fluctuations of the hospital<br />
daily census: An important health planning Lool. Mcd Care 10:118 Mar.-Apr.<br />
1972.<br />
5. Hancock, W.M., D.M. Warner, S. Heda, and P. Fuhs. Admissions Scheduling<br />
and Control Systems. In J.R. Griffith, W.M. Hancock, and F.C. Munson (eds.),<br />
Cost Control in Hospitals, pp. 150-185. Ann Arbor, MI: Health Administration<br />
Press, 1976.<br />
6. Johnston. C.M., W.M. Hancock, and D. Steiger. The First Three Months of Im.<br />
plementation of ¡he Admissions Scheduling and Control System at Delta Hospital.<br />
Report No. 75-9. Bureau of Hospital Administration, University of<br />
Michigan, 1975.<br />
7. Yannitelli, P.F. and W.M. Hancock. Implementation of ¡he Admissions Scheduling<br />
and Control System into Charles Hospital. Report No. 75-3. Bureau of<br />
Hospital Administration, University of Michigan, 1975.<br />
8. Handyside, A.J. and D. Morris. Simulation of emergency b. d occupancy. Health<br />
Serv Res 2:287 Fall-Winter 1967.<br />
9. Young, J.P. Stabilization of inpatent bed occupancy through control of admissions.<br />
HospitaLs 39:41 Oct. 1, 1965.<br />
10. Balintfy, J.L. Mathenatical Models and Analysis of Certain Stochastic Processes<br />
in General Hospiltai. Doctoral dissertation, Department of Engineering, Johns<br />
Hopkins University, 1962.<br />
11. Hamilton, R.A., W.M. Hancock, and K.J. Hawley. The ¿Admissioun Schcduling<br />
and Control Systen: The Admissions Simulator. Report No. 75-1, Bureau of<br />
Hospital Administration, Univernity of Michigan, 1974.<br />
12. Hancock, W.M., J.B. Martin, and R.H. Storer. Simulation-based occupancy recommendations<br />
for adult medical/surgical units usiiñg admisions scheduling<br />
systems. Inquiry 15:25 Mar. 1978.<br />
SIMULATION<br />
<strong>OF</strong> HOSPITAL<br />
OCCUPANCY
#12<br />
Estinating the Need for Additional<br />
Primary Care Physicians<br />
By Arntbmy Hinddk, Nicholas Dierckman, Charles R. Slandridge,<br />
Harry DVlchcr, Raymond Murray, and A. Alan B. Prisker<br />
A /uems approach i¡ used to ea^ the primary health care delivery<br />
system in Indiana. The outpui (ofce viit) of prinmary care physidcana i<br />
estimated and compared with the demand for her r vicea. Indexes of de.<br />
mand, aupply. cou, and need are derived and used to determine the addi.<br />
ton u aumbr of priry care phycanada n d in ac urea. The raesul<br />
ol thb study are belh used to encorage aduating medical tudents to<br />
pr~ in ua in naed of additiomnl prima medial care.<br />
PRimuy medical catu has becon an are~ of- oonen because of<br />
the ppa deere in the umber of primary medical care proid.<br />
e m specdly g8eral and ahmily pantido;ne inD tbe United Sancs<br />
and spdcklly in tdie ut of lndiana [1-S]. A tchnique was dcvcl.<br />
oped la thib remebc to ~umr the primary health car delivery sy~<br />
in Indima and to provide inmaIua regaprding the ned for addi.<br />
tiaN pd~ care phystam nla drcat areu of tbe sate.<br />
Dibcuuom bet~w qms anm mullns t Purdue Universiy and<br />
phbiu am at the R]qenrieef Instute for Health Care revled that<br />
li ord or r the a modl be ushlf, it parame~t would haye to be<br />
dma b Ol actua data. Thus de modeling proca wu con.<br />
Uda~ed by tbe aivblM ky of dnu prduding for xample, considaea<br />
rb d lt e fie of Shnncim ma as Blue Cros/Blue<br />
Shied, M icare, d Medicaid. A discuion of thes modeling i¡nes<br />
can be formd n hnddg, Pri , and Delche [4].<br />
Meha.d¡o y for Aein Primay Medical Care Servie<br />
hPby M01a Cmar avk A s<br />
ac h in ll n [S,6] have dscribed the distribution of<br />
pTimay care enics by using rmii of population per primary carc<br />
TkL rs--- r& sJ mppaorad by had Rngguari~ IgJfutaf, 4 divion of thc<br />
Rrsr,. .uJtUo~. c,. IlpdU.~<br />
dd _amuum n~ r rad f sa er r~rInu lo Charlu R. Stdndri4e.<br />
imt. Pons, C e.l ,M~Lw. Ssteu D~vls¡i. Unrsitb ofl 1o°,<br />
¡m* Cal, 1. ,I 1 HI i udb U· akclmr in m* d.~mmta of opverU~om<br />
ALTaU m *,Sl V.ItIU > e rLmmau~; N~k Dkr~ .b k da mlesm ~aIonm e-.<br />
u av M Ld by T.e*sk.<br />
8|l<br />
MNd~icl lJ lorvmin<br />
7 Dur . de a lnur<br />
SJstrs CorporAlJio;<br />
eJl ume,,u, nm. Umwnivn; R~ymnd MUvU<br />
p1refullr a4d ec mmi . t d rsn0 of mId~nMe, MicAhigin SSi.e Uni.<br />
nwry; ed U. 1 1. pJ r. r proao~r in hA S~hool olnduurial Engincrnng.<br />
SM l~?74WO~r//(1oc/;T. oo/o<br />
O 197) H eial !facr uF d E.dumaloal Tnuri
-- 2ti4 --<br />
physician in a county. However, a political unit like a county may<br />
not accurately represent a medical service area since it is possible for<br />
cities of subustantial population to be located relatively doe to a<br />
county line, thus providing medical care to residents of contiguous<br />
counties,. or lor physiciana to be located within casy acces of people<br />
lrom another county.<br />
In this study, pimary medical care service arcas are defined as<br />
population cetera and their environs, specifically, towns or cities with<br />
population of at least 2,000 (the approximate number of people per<br />
primary care physician in the United States [7]) plus thc people in the<br />
immediate environs of these towns or citie. The environs are defined<br />
as the area within a five-mile radius of the town or city since<br />
that is a reasonable distane o travel to a physician. If the boundary<br />
drawn around the city overlaps that of another city, a combined service<br />
area re uluL Acording to this definltion, Indiana contains 79<br />
primay care atate's rc. The counties are grouped into 12 districts.<br />
each of which u divided into primuary care center and the residual<br />
rural area surrounding he centers (lee accompanying figure, p. 292).<br />
F himain cthe Capadty of the FulLTime Primury Care Pbysdcin<br />
A f~ e priamuy are r P) phylan is defined as a general<br />
or fmmly practition the age group S3S9, wh!-h he, the highest<br />
utput in term O visitu per year fOr this speciaty 8]. (Tables 1 and<br />
2, p. 29.) Prmary care phyiciam are condred to comprise nonfed.<br />
aeralo a~bed .hyidam, boCd medical anad ostophic, who are<br />
gen ralmd * aMaily pationer, pediariciba, internis, obstetriciangYo{o{<br />
or ger~ l faoo The output of one ~FPC physician<br />
a d~mdas he nusber o prma are visits per year for a general<br />
« fnilyS prncdt r in the a ge group 5-9. The output of phypiciam<br />
wt oth r ad spedlty charalt b expresed as a percmte~<br />
d tbe output of tde IMPC pbydian. Vitsa per week and<br />
we~s praciem pr yar by an FFPC phyuidan were computed from<br />
Rc
Pri c= arvicc a ia Indina.<br />
- 245 -
- 246 -<br />
Table 1. Relative Numb of Primary Care ViLt iuFOR u<br />
ft, Di~rent Speciahi~ FHYSICIANS<br />
SViddty Weeks/ Rclative vliitf/<br />
day yedar year<br />
Genral and hmlly .. 3931<br />
Internal medLcine .... 2095<br />
Ped latrtic ............ 3.1<br />
47.73<br />
47.20<br />
47.77<br />
1.000<br />
0.24<br />
0~25<br />
Obbanrñ.gy ldog . 2714<br />
CaGe n l urgry ..... 1873<br />
47.70<br />
47.0<br />
0.i2<br />
0.4M7<br />
E' l lted Ir.. Ddkber. Ra>tckh, and Murray 19.<br />
Et tlmated (rom Rrfernce Dato o, the Profil of Medical<br />
Prt"rc [-lll.<br />
incom of $15,000 and over since it is amumed that this income group<br />
has all of iu expreed demand satisfied and would be able to bear the<br />
full monetary cos of receiving care. In 1971 people in this income<br />
group visited all phycians at the rate of 5.1 viits per year, and, of<br />
thee, 3.0 viiut were to primary care physlcians [15].<br />
For he purpoS of this study, the ideal population i3 also defined<br />
as having damoep phic characriuica similar to the population of<br />
Indiana and it la sumed tht geogrphic acccaibility to .. m-a care<br />
(pentage of the potentlal demand that is expreued ae allowing<br />
for die comt &njd iíuavenlnce of traveling to a phypician) for this<br />
group l tihe ame au the average geopaphik accessbility for Indiana,<br />
whkch rus esablUb u a 0.9373. Thc demand rate for primary care<br />
ot be ideal population n thbn be calculted u 3.0/0.9373 or 3.20<br />
visiu Thaefore dth yearly capacity of an FTPC physician i 8,762/<br />
320 or 2700 individuals of the ideal population. With this informa.<br />
tion, an algorithn has been developed for obtaining indexes of pri.<br />
ary care delivery for the previoudly defned service areas.<br />
Tbl . ui~ve Nu~be d ViI Atene~ by<br />
Giernal Und Faiy PCra of D ut<br />
Ae G~<br />
(Sore: 5l~dr~ et aL [U8<br />
yer<br />
Unde 16 0.12<br />
vI39 UA24<br />
45-49 0191<br />
55-69 9.10<br />
¡(1~0-em6( amasI~<br />
Owd~~~-BO~~.~~ 0127dP ~ ~<br />
~FALL<br />
~~1978<br />
Ore.. _ . .~~~~~~~~~~~~~~~~~~~
. 1' - -<br />
IIINDLE Algorithmn for Determiuiang Pámu-y Care Service Index<br />
£T1 AL 1. Calculalc hce Equnwlnit Number of FTPC Physicians in Each<br />
Service Area. The visits attlilAde by each physician can be expressed<br />
relative to those attended by tLe FTPC physician as a function cf<br />
age and specialty (8-12,16-18]. For comparison among specialties<br />
(Table 1), the number of visits attended per day is estimated from the<br />
Delcher, Raykovich, and hMurra.y rtudy of Indiana physicians [19].<br />
The weeks worked per year are estimated from Reference Data on the<br />
Profie of Medical Praclice [9-111]. The days worked per week are assumed<br />
not to vary by specialty.<br />
Similarly, the output of physicianu can be compared among age<br />
groupa Standridge et al. [8 report relative values for general and<br />
family practitionen in Indiana (Table 2). Age and output are assumed<br />
to be independent of spccialty because the available data do<br />
not allow estimation of the relationship between age and output as a<br />
function ofl pecialty.<br />
The output of cach physician in a service ares, expressed as a<br />
percentage of the outpu of the FTPC physician, is computed as the<br />
product of the relative number of vuiiu of tlose in the specialty and<br />
the relative number of visita of those in the age group of that physi.<br />
cian (see Tables 1 and 2). Then. the number of FTPC physicians in<br />
a mervice area is the sum of these producu for all the physicians in<br />
that ure<br />
Physician extendern. that is, physician asistants and nunre practiuoa,<br />
acr not included in the model. Standridge [1] estimated that<br />
thee providen supplied leu than 0.S percent of the primary arre visit<br />
in Indina in 1975. However, it would be easy to extend the model<br />
to include thee províders of primary care.<br />
2. Compute a CGographic Acce#ibility Measure. Geographic accembility<br />
is defined as the percentage of the potential demand that<br />
becomes expr~eed demand after allowing for the cost and inconvenenc<br />
of traveling to a phyician. The accessibility measure is derived<br />
by auín g that &lU the people in a Mevice area are saved by the<br />
phyic amn located in that area The simplest case is the mall, appraitnmely<br />
circular, single.phyican area. If the population is randomly<br />
located within the area, thbe minimum expected distance to the<br />
pbh ui given by locauing the phydiclan in the center of the area.<br />
The appropriate model for this situation was developed by Eilon,<br />
Wauon ydy, and Chriitod [20].<br />
The problan becores more difficult ii the area contains more<br />
than ae pbys~ n loca~ion, but, lor most areas, use of a nearestlocation<br />
algorithm produces a set of polygons with the physician cenrally<br />
located in each polygon. The area of the individual polygon is<br />
estimated a the arca of the wrvice area divided by the number of<br />
physidan locationa. Although a precie result for expected distance<br />
HALST to the phyaician it not pouiLlc, a lower bound is given by assuming<br />
«zMUN dcircular subareas. Experimenul procedures and a sensitivity analysis<br />
lCd to the selection of this pro"dure [21]. Thus the expectdl Cartesian<br />
distance to the phytician in miles is given by
O.667(A/(wL))I<br />
where A is the area of the servce area in square miles and L is the<br />
number of physician locatio;s in ihe service auea. Expected distaníce<br />
was etimated for each revice area allowing for the different types of<br />
practice--olo, partnerhip, aid group [22]. A convernion factor, estimated<br />
to be 13 [22]. was employed o convert expected distance into<br />
expected road distance.<br />
Lacking informatin specific to Indiana, we anumed a simple<br />
linear relationship betnen distance and demand rate. Using data<br />
obtained from a sudy by Kane [2]J, we estimated the sope of this<br />
line aud ausumed that the rclatiozhip observed for rural Kentucky<br />
would also hold for rural Indiana becae of similar topography. This<br />
set of assumptiocs led to the following equation for ,eographic accessibility<br />
in a service ara:<br />
4CCESS, = 100 - 2.5D<br />
where ACCESS i the geopphic acceibility in tervice area j, expresed<br />
as pe ntge, and DJ is tbe pectd~ road distance to physidcum<br />
in lerv ~ j. The lMerpreta~on of the ucembility calculatian<br />
b ti 100-ACCESI b tbe percentage of potential demand<br />
tha doaes n bcoe exprced demand becaue of distance to a<br />
physidan.<br />
3. Com>ap #e ],ct ofl c omic St tusw on Expresucd tcmannd.<br />
A ponaran :J Ph. potental demand kfr primary medical care is de-<br />
Bflead by hc moaat ourn of obulning r The ecoaomic fecai.<br />
blit7 of ob~ning cue b defined oa the br of restricted activity<br />
dap par ymr, mui tr daa uad p~ccdurcs of Weds and Greenlick<br />
[24]. As down la Table 8, peraina in low.inmme famillie ned more<br />
mM~i l am thih pan In amll~ with bigher jcmnas It b as.<br />
anme d (mnd tbis maumptou ba borne out by the data in Tabl 3) that<br />
the hgber a fuity LaoCe. the arg the percentage of needa (po.<br />
tental d and) ezxpea ua visita to physician. It is further assumed<br />
TaS 8 Ceompma f _ dmaic Pembili Index<br />
ldana iicv<br />
o / , P restzLCted ~rlbilty<br />
NED FOIL<br />
PRaIMLRY CARE<br />
PHYSICIANS<br />
- 249 -<br />
HINDLE that all tlie primary medical care needs of those perons whose family<br />
tT AL incomes are $15,000 or greater arc expresed as demands for physician<br />
servics-that i¡a, economic feasibility is indexed as a functijn of their<br />
satisfied demand for ervices (»e Table for a]culationf).<br />
The following logarithmic function is used to calculate the eco.<br />
nomic feasibility index for each servic area:<br />
FEAS, =oax In(l)+ b<br />
wlhere FEAS i¡ the index of economic leasibility (expreued as a percentage)<br />
for service area j, I is average family income in service arca j,<br />
and a and b are cosants to be atimated by regression analysis. The<br />
values of 1 used wer tbe midpoints of the income categories except<br />
for the highest category, for which $15,000 was used. Uaing the data<br />
in Table 5, regression analyas yielded values of 0.274 and -1.68 for<br />
a and b, rapecaively, with an lS of 0.955.<br />
The interpretaion of these calculation ia that 100-FEASj is<br />
the porio of tb potential den d in a service are that does not<br />
bcoome expreued demand because of the monetary cost of primary<br />
hcalth are.<br />
4. ComputM Ihe Potentlh Demand. Potential demand ui the ned<br />
for primary halth care as expericed by the population. disregarding<br />
factor that could interfere with satifaction of that need [112,1].<br />
This tbhe demand the population would place on the provider of<br />
primay cdre the cost of obaining such care, both monetary and<br />
no me cty , ee aro and, of course, auming that the population<br />
l uniformly able to reco~el conditioa for which medical care ia<br />
Potenial demand bi conderd bere as a lunction of two charactaik<br />
of he populatio: age aMd need for car (15, 25-29]. The<br />
idml populuoua aiunaed to have the ame age distribution as the<br />
mute of Indiana. The average utilization rate for the ideal popula.<br />
tion of ldiana (
250 -<br />
Table 4. Primary Cre Ulization Rates by<br />
Patient Age Group<br />
Visu/penon/<br />
Age grup r«<br />
(4) ((.)<br />
Under 18 229<br />
O18r 2<br />
Over 64 4D0<br />
· ii i Bi i~~~~~~~~~~~~~~~~~~~<br />
The mean number of restricted activity or bcd days for the popu.<br />
lation of the service area lb ic dewmined as the population.weighbted<br />
average of restricted activity daya over the income groups. The mean<br />
number of retriced activity days by income group is estimated from<br />
data ia ref. $1 and 32 snd prented in Table 5.<br />
i T eThee calculatioau for age d family income are used to deter<br />
mine the poateial demanud in numbers of the ideal population in a<br />
given service ar by the folowing equation:<br />
ve, = N, X (1/o) x (x/Bo)<br />
where Yot is tb potencial demand in unitu of the ideal population for<br />
rvce area j and NI b the ictual population in wervice area j.<br />
5. Dc:..íin: he; Exprcued Dcmund. Al of the potential demaid<br />
bowever, will not be expre~ed as visiu to physiciau. Facton<br />
that may impede some people frn making visita to physicians must<br />
be tuar fito -aaat [18). Two such factor georaphic acceibility<br />
and econoaic kfalbilty, are ~ite into accIunt in tdh model and are<br />
auumed to act depently of one another. Thub the expresed<br />
deAnad iD a serviC are, VY, is obtained by multiplying the potential<br />
dena i that & ares, Y, by tbe a:eibiliUty and economic feasibility<br />
factor. tltarea a com caputed in seps 2 and 3:<br />
Y, = ej, x FEAS, X ACCESS,<br />
Tibe 5. admad ~ c d ky Dhys<br />
of Pathemtn la DI t ame Cm p<br />
Eniad a~ed<br />
Incrue aouy mvty.dap<br />
Under powny kwlt a0.<br />
Owr poway idl aid<br />
¡e a $15000D 14.<br />
15G000 ad over llJ!<br />
* rjasdd frk de b a Ddm.b* D~ I31) ud C.^u o1<br />
to U.u: ¡1f0 p1.<br />
t *u. Cn_ .f oL.U~: 19f0 (o .<br />
NEFD FOR<br />
PRIMARY CARE<br />
PHYSICIANS<br />
FALL<br />
197'
- 251 -<br />
HINDLE 6. Computc Mhe Availability Index. Availability is defined as the<br />
rT AL percentage of the expres~ed demand that is satisfied by the suppliers<br />
of primary care, thit is, that becomes satisfied demand. The latter is<br />
defined as the amount of medical services actually given by the providers<br />
of primary bealth care in responwe to population demand [15,<br />
33]. An availability index is costrued based on a model of the<br />
services that flow arou the service area boundariea. The basic assumptions<br />
of this model are:<br />
1. If the phyiciam have spare capacity after all the expred<br />
demands of thdi individuals in thc ame service area are satisfied,<br />
this spare capacity is made avalable to the adjacent rural arca.<br />
2. If people in a defined service arca can receive bectt service in<br />
the rural area, they will make demanda on the primary care physi.<br />
ciana located there.<br />
3. Persons do not coua district boundaries in order to obtain<br />
primary medical care services.<br />
Tbe availability index is defined as the ratio of the supply of visita<br />
available in the sevice ara to the expreud demand. The supply<br />
available Ia ic initial supply plus (minus) the amount of supply<br />
transferrd into (out of) the rvice area. The availability index for<br />
a service area (AVAILj) is computed by the following formula:<br />
A VrAIL, = (MDi x P)/V,<br />
whele MD a tbc number of FTPC phyidan in area j, P is the capac<br />
ity of owne FTPC physidan in teru of numbera of the ideal popula.<br />
tios aid Yt ex pr ed deanandin service aea j (the total number<br />
of phyiia n visits or the yer). An it¡raive procedure was developed<br />
o Mind the miber of FPC phy~dm in service ea j udng the<br />
tbree auumpiuas dacri be awa aud applied to each of the<br />
db.ua Im dpcadzaalty.<br />
7. Comnpulk tkl Primn, Care Sericc Index. The primary care<br />
cerl index lfr a evice ae (PCSI) is defined as te ratio of thc<br />
sttald Ad to bc poteCtial demand-tha t ¡s, is it the product<br />
of tbc exa deand demmmand the availability index, divided by the<br />
potential denad expreed a a percentage:<br />
PCSI, = (Y x AVAILj)/V,,<br />
This index i¡ thus the percentage of the potential demand that is<br />
atidiied.<br />
8. Comte khe Phtician Requirement and Need Factors. The<br />
pbhykin ruequirment fMctor, XMD, is the number of additional<br />
FTPC phy~idam that would be required in order to aatisfy the expeed<br />
demand t i not<br />
m ncucrendy being met:<br />
IHALTH<br />
UVA xZ<br />
XMD,=(v,/P)-MDj,<br />
where V ¡ the expr~ed demand in savice arca j (the total number<br />
of pbhyicin visiu pr year for the aa,. in numbenr of the ideal popu.
- 252 -<br />
lation); MDJ is the total number of FTPC physicians in service area NF- FOR<br />
j; and P is the patient capacity of one FTPC physician in numbers PMARY CARE<br />
of the ideal population. The physician requirement factor for each<br />
district is the sum of the requirement factors for the service areas in<br />
tlae district.<br />
The need factor is the estimated average number of member of<br />
the ideal population who are beyond the capacity of each FTPC physician<br />
to serve but who would have to be served in order to satisfy that<br />
portion of the ex~presed demand that is not currently being satisfied.<br />
The need factor, XP/. is expressed as follows:<br />
XP, = ',/MD,-P<br />
The need factor for each district, XPd, is<br />
XP, = (XMD, x P)/MD,<br />
where XMD, i, the number of additional TPC physicians required<br />
to atiify that portion of epressed demand that is not cumnrently being<br />
met in district d and MD 1 is the total number of FTPC phyicians in<br />
disrit d<br />
Meru~ df Eecue of tbe Prmary Medical Came System<br />
ElEctiv«ee indexes provide a mesure of the capability of the<br />
primary a e povida e in ach servtce are to met the demand of the<br />
popultion of that rca. To aras the performance of the primary<br />
medial care divs sd>em of a state, a policymaker need satewide<br />
mnaMures of effectiveane Several maurcs of performance that can<br />
be deived fron the inkd t aure diumed below.<br />
Iudtxa Raekd to Minimum LmbL of Serice or Availability.<br />
Fomulon of<br />
tto n that tbe g<br />
tme mem of effecuiveai i¡ based on the a*ump.<br />
o oí he poficy~ that some minimum level of<br />
eitbe the ervi ~ de a va;iabity idex is obtainrL The per.<br />
cetage of arvie u that have index values below a defined minimum<br />
leved 1 one uh meaure. Alarnatively, a population.weighted<br />
average of index levd below tbe minimum level ould be used.<br />
Popuwlio.Seighek d ldex por tl Stc. This measure combine<br />
the indexes lfr the ~rvc ar by multiplying either the primary<br />
care ice ind or the avaiblty inde for a particular service<br />
ares by the fraction of the Mate*' populaion in that arca and sum.<br />
ming the produc of ll aras.<br />
Pkhyucin R gquiremnt Factor for thc Stal. This measure is the<br />
number of additonal FIPC phucians needr in the state to atíify<br />
all of the exprsed demand<br />
of the serve area<br />
and is the aum of thd requirement factors<br />
The Analy for Indiana<br />
The procedure developed in thi reecarch is being used to evaluate<br />
the primary health care system of Indiana. It was fint uced in F<br />
1976 by the Board of Trusaes of the Indiana Medical Diustribution<br />
Loan Fund to identify areas in need of primary care physicians.
- 253 -<br />
HINDLA Tablek Meamm of Zficvemn of the Prmary<br />
Medal Care Sm: lndin, 1975<br />
Ma~wr Value<br />
ALAITH<br />
s=vK:M<br />
Pe~rct merice amas wih<br />
srvke lnd bdow 70 43.9<br />
Prca ewvice aras with<br />
avnbllWty bebow 85% 0.8<br />
Populatobn-wdghted<br />
mkr ha (%) 69.6<br />
Popula~i.wdlghtd<br />
avaiblUlty ~da (%) 87.1<br />
sauwi. pbhdd<br />
requrrn factor 251<br />
Data Soura for Physicain and Population<br />
Data conning primary care pbyaician in Indiana and their<br />
cbahnaairs wcrc obuined rom Lhe Indiana Physicimn Proile [7].<br />
Dma com.ning the dic and age distribution of Indimaa'. population<br />
were hb d oD tdc Indi~n Coun"y Popuhbtion Projections [301. The<br />
kvel of family incme in each crvce ara was derived from data in<br />
tie 1970 United Suite Ceuus [32].<br />
Rwail for tbc Btac d Indiana<br />
Tabe 6 summri the meaures of effectivenes of the primary<br />
medical arm sym of Indiana. It hows that 45.9 percent of the<br />
avice area bad a service inde of ls than 70 percent or that 43.9<br />
p~ t oe thc svice arca* were meeting lesa than 70 percent of the<br />
poentdal demamd F\uermore, 80.8 percent of the srvice areas hsd<br />
phul dan avalability ~ndexa that were lower than 85 percent.<br />
The popultionweighted wrvice index shows that le¡s than 70<br />
Table 7. lh~y an ll equiteme and Need<br />
Fpaca for Ind DhIm<br />
Phda Need factor:<br />
Di~ requl~t Idal pop/<br />
bctwor phydan<br />
I. Gary .....................<br />
2. Stih ida ...............<br />
8. Fort Wa ....<br />
4. Laayet .................<br />
5. Aam .................<br />
6. Te ame ..............<br />
7. diampol ..<br />
ILicuo m t. ~ ...............<br />
g. I doid~ ..............<br />
0o. Lawmm~bua g .............<br />
¡i. vanl .................<br />
12. N Alb.oy .........<br />
0<br />
45<br />
35.4<br />
8.7<br />
2.7<br />
21.4<br />
4............ .1<br />
6.6<br />
s.s<br />
.419<br />
28.9<br />
143<br />
348<br />
59<br />
62i<br />
261<br />
415<br />
748<br />
291<br />
220<br />
97<br />
610<br />
521<br />
i i ,
- 254 -<br />
Table 8. Service Arcas with Need Factorn Greater than 900<br />
Accfc Economlc Avail- Prim"ry Physician<br />
Service Aclt Need<br />
arta ~Ser*iac~ ribility ublmt fueasiiú rbilt ice e air. c ec-. factor<br />
*rre tndex inde index indx O<br />
Lawrence.<br />
burg-nrl ...... 77 79 37 22 11.8 4 418<br />
Fort Waynerurail<br />
........... 83 U 44 31 17» 8302<br />
Muton .......... 91 84 44 33 2.9 03(<br />
Angola ........... 92 79 46 34 2.3 506o<br />
New Albanyrurai<br />
........... 79 78 49 30 10.1 2 753<br />
Terre Iauterual<br />
........... 8D 80 52 33 11.3 2428<br />
l0oo0ote ......... 89 79 54 58 1.0 2291<br />
Zvamvlukrural<br />
........... 77 80 54 3 12.7 2291<br />
Hmuinuro ....... 94 84 62 49 3. 1 595<br />
ML Vcmon ....... 93 79 63 46 1. 1527<br />
Bol~ ........ 9 80 52 3S 113 I1475<br />
G~ry-t i ........ 84 80 66 45 9.2 139<br />
Ktn t~bnm ...... 89 81 67 48 0. 1 20<br />
iatal ........... 81 81 67 44 .820<br />
uval ........... 3 U8 8 47 9 1 215<br />
S F-o- - ........... ®e 77 71 so 0.7 099<br />
Lsil ............. 93 78 72 52 1. 1 m2<br />
percen of the ponti al demand can be satisld. The population.<br />
m~tged avalabilty indae ahows that 87 percet of expred demn~d<br />
¡ uatid. The value of the utaewde pbycian requirement<br />
factor ¡i 251, which shows that an additional 251 FTPC phyicians are<br />
needed in oard to meet bhe 18 prent of the expr~ued demand that<br />
i not a~ed Sincte fullm~ physician by definition provides thce<br />
mont viui per year of any phy~ln, the requirement factor may be<br />
viewd u the minimum number of additional physician required.<br />
ul fo Iai Dh ta<br />
The requirenmt factor and need factor for cach of the 12 Indiana<br />
district are presented in Tabk 7. The need factor reflects both<br />
pimuy care availability ad the extra work each phycian has to<br />
perL>rm if he o he ab to suisfy al of the capresed demand. Table<br />
7 shows tha 8 of the 12 ditu have need facton of 10 prcent or<br />
more of the capaclty of an F phyiscian (2,700) and four disricts<br />
have oecd facto d 20 paret ~ mare of thb value Thee result<br />
indicate that he demad for care placed on primar care phyicin<br />
in di.:' -o in aioU put of Indoiana snifsamtly exceed their capacity<br />
for providing such care.<br />
NEED FOR<br />
PRiMARY CARE<br />
PHYSICIANS<br />
FALL<br />
1978<br />
e
HINDLE<br />
Tr AL<br />
HIALTH<br />
falvCU<br />
- 255 -<br />
Table 9. Cumulative Distribution of Service Area<br />
Need Factors by Prcent of the Equivalent<br />
FTPC Capacity<br />
Lmee Number of Percent of<br />
pe t 1service<br />
a reas cervice arcas<br />
All ......................<br />
O .......................<br />
91<br />
40<br />
100.0<br />
44.0<br />
0-10 .................... 1 165<br />
10-20 ...................<br />
2-30 ....................<br />
40-60 ...................<br />
Ii<br />
8<br />
9<br />
12.1<br />
8.8<br />
9.9<br />
70 ................... -O<br />
90-100 ..................<br />
0<br />
S<br />
0.0<br />
SJ<br />
100-170 ................. 5 55<br />
ielu for Sevia Aras<br />
Values fo the gographic accessibility index, the economic feasibility<br />
index, the availability indcx, the primary care service index, the<br />
physician requiremnt factor, and the need factor were compiled for<br />
cach ervice area. Table 8 (p. 501) shows those 17 areas with need facton<br />
greater than 900, which is one-third of the capacity of one FTPC<br />
phidian.<br />
Finally the distribution of the arvice area need factorn in term of<br />
perct nuga of the iTPC phyician capacity (2,700) is thown in Table<br />
9. The tabla that ian ader to met all of the cpreued demand<br />
in the tate of Indiana, each physidan in 36 of the service arcas would<br />
hae to arry a paient lo bd at let 10 percent higher than hib or her<br />
esm ed maximam. In 17 of the service areas, ach phypician would<br />
haye to are for at lest 40 pernt nore patienta than his or her<br />
maximumw. Table 8 sbows that a a dditional number of phyidamn<br />
equivalnt to 11 FWC I phyaicuana required to meet the exprsued<br />
demad ln these 17 service are On dhe other hand, 40 service areas<br />
wer found to have no nced of additional primary care phyiciaan.<br />
Applk dof aria Idiana<br />
BeCginnig in Apil 1976, thc ramurch has ben used to usist the<br />
manben of thbe Bard of Truac~s o #he Indiana Medical Diutrbutba<br />
Loan Fund to determine the aru in Indiana in greatest need<br />
of addtblmal primary are phyici . The fund is a loan-forgivene<br />
pom that rwppar medical students who agree, in exchn~ge, to<br />
practic primary mdical care in an aea of m ed. Studenu funded by<br />
this pogram recive a list of the ar in Indiana in greatest need of<br />
additol primary care pbyucia, and medical graduaa select practice<br />
lacaom jintld with the loan fund board of truAte lndiana<br />
has about S00 m gaduates per year, and 95 studenu have par.<br />
tidpated in bis prnuo~ to date. Sixtyfour of these are in postgradute<br />
tralin and ave a prici n phypia The remainig 26<br />
are itl i medial c oL It b hoped tha this research will continue
in helping to rectify the maldistribution of primary care physicians NIED FOR<br />
;! ~~~~~Indiana;~ . MPRIMARY CARE<br />
PHYSICIANS<br />
REFERENCES<br />
1. Standridgc. Prima., Jielthi Care Man power Projeclions and Polic AuLcu<br />
men,. Matr' tha4 Shool of Induul ZngJEcring, Purdue Unlerity,<br />
Aug. 1977.<br />
2. 1970 Americn Mcdil Directory. Ch~lop: Acn Medical AoclatIoa. 1970.<br />
3. 1973 Ameri¡cm Medll thcctory. Ch~ko: Acra~ Mcdial Amaton, 1973.<br />
4. Standridg, -R., A.A.L. PRiL~r. and H. Ddch«r. Ier in the ddop t of<br />
a health mapower pnlnng ~mod. Simhdtion 31:9 july 1i7a<br />
5. Axdroo. S. &nd . Murray. lndiarn Pthyiu aud Rural Healh. Rq lf<br />
Instutute Rtpon. Rtgnx Innit.e, Indanpolls, IN. Oct. 1974.<br />
6. Boruff, J. Dldbuat¡in of phyl~dus ISBH Bul 76:3 July 1972.<br />
7. IndiaMn Phtkien Proile. Seven Area-Wlde Comprehbivc Health Ptmnning<br />
Ag~es o Indiana and Ocalth Servccs Manlag~gt. Inc., Indianapolls, IN,<br />
Dec. 1975.<br />
8. Suandrldge. C.R, C. Macal. A... Prkáer, H. Dclha, and . Murny. A Sim.<br />
atoo Mlodol 1 te Pra~ y Hk~l Cre S o Indian. In IIJ. H4hland,<br />
.GIL: iJe. ad J.W. Shmldt (edL). ProcdQ of tha Wfinr SimuhaUp<br />
CCrm.~, P. -359. GaltUsbus MD. Dec. 1977.<br />
9. CCLntor I hmloa Saian m dmrch ad b.Developme. Refer~a Do os fa<br />
Prkb of AMd~MI rtrfk, iJ7. Cha . Amian Mcdlcal AodItbno, 9P7.<br />
10. Cmnau m h svias~ IRe b and b RafStrK~n Daot o fthe<br />
uwg Mia Pre tica, 1973. cao: u n Mcdicl Amodaon, 1974.<br />
II. Care b§r lcalh crvioa iraach a sd DCevlopmL Rorf*nce Data on the<br />
P~ et A.'-c Pra, 1974. ica: m Mdal AoLbn 1975.<br />
¡L D_ d Ja, A. >e/ . Mé~cl Cm AdmhsUtá ¿ro: speif$ng Requrcn~<br />
or H~ CavL C&bd MA : P~d Unvi.a:y Per. 1973.<br />
¡i Wa T. and 5. a~ml Sr . A<br />
ana o th e b derlnanu oC phydan<br />
utúb~mda. a.r? p~.'nted at the lOs anual meeticng o the Am~ean<br />
bic HL A c ~ m a sa., San F~l. CA. Nov. 1975.<br />
14 Ay. L Iami:e d amu barrri ta e u of neted ditnkl r.<br />
lar MYd Co, m 15:44 J~ _1.<br />
U5 N# fw b hl&yb ~ada a. P , Voluma, ud Intamil<br />
&Um Lat VlOd, U~Jbd SM~di-i1. Vital Id Haltb Sicstiat Pubeia-as<br />
S«l 10, No. 97. DUW ib. No. (HIA) 7f152L Wahizgo. DC. UV5.<br />
G- t~mri d 08 , Mar. 1975.<br />
10. A Pdl Puml~ Cutan Phls ln Natoa~ Dlos~o and Thapeuftc In.<br />
da. Vda. 4 No. Al, PlA: PAI AmArla LUd. Jume 1975.<br />
17. VaMbda, LG. Unbtdka M Uplda kS lSe« In S.G. Vahovic anud P.<br />
Ahbv (eda.). Rfenr cait D o r Ah M ot MJdlal Prcie, 197. pp. 47o0.<br />
~ p Am~eria M~eda AIodaex~ 1974.<br />
I t L ¡~ J. phidmi A . la ~o se rc~ Qanarllica id P er.<br />
tra. la §.. LJ W w . Ab. A . d G.A. Ityui (ed&). RlJrrnc Di oen<br />
th& i~ Af ~7 I073. 3.s~, pp W=M. a po: Am~eri n Mial<br />
19 Daa . , %DdId , d .L amay. A ur t ludIn Ph!r~u'<br />
iJ~k CGnJ,~i &%b Tea kka~n. uui litute pot.TL<br />
Rmk~r l c. lUiaa g, Nl. M. 1!r. l<br />
0 San, S. CN. Wa*Osmdo. G md í. s~Tdes DltrbtU ManaKuerntl:<br />
ilath~.imUrl odWUi amd P lyulJs Nie Yak: Hatnmr. 1971.<br />
21. ldk. A. mod N. Dlitua- M>owir fr Pimuryi Madl~ Car in In l o.<br />
Repmtld laUnh lekpart. PImr Insgthe. lndnapola IN, July 197S.<br />
22. Dklremaa. NJ. P r JediCl Cm i ld. Matl s thaci, Schod d<br />
,Idud l Rhcarcek~ Purde Um~dVsly. Aug 19¡97<br />
23. &aum. RL Dacbtlb d hbl ai r pioritm and acpcuationa~ ,m<br />
ruIa mm HML Jnm k R 4:142 Sumin, 1¡09.<br />
24. Wdm . CawnLkh Deisnaa o medial lar utlllation: The d.<br />
len do l dn ~d dia mc a acu t h e ik l cure si Med<br />
C4m 8i:4M N v.-D 19. FALL<br />
23. Aday. L mud La lUdahom. ThA UUtl¿tlobn of Siuth ~es: lndiu d 1978<br />
Co~rasL DHLW Pub. No. (aM) 7ISM0. Wad~l. DC: U.S. Goern<br />
-t iU Or~. Dec. 1973.
- 257 -<br />
HIiDLZ 26. Ado, An . ad L. A adIca Patrn d Use ol Health Serics. In HzL<br />
IT AL F eman. . Levine, ad 1LG. IRMe d(). Hidbod o1 Mcdl S.oloO ,<br />
pp. 353.60. tngleeod (Wt NJ: h~mkes-Hal 12.<br />
27. Asdeno . O. ud J. Ne~ Sodal ad bdMduml denimu¡sau of medal<br />
oase utlLoai 1tihe Unlied Sate. YMUlabm Atn Pid Q 51:95 Winaer<br />
mPV~s<br />
HtlTl~l mVM<br />
RURAIM<br />
S. adas, L uad O. Ando. A Dmd o/ 1m Shiv as. Chlago: Unlier.<br />
dq dof Cbop P, 9in.<br />
29. li, T. .and L Wbhc. Yaoa re bid to te bw os bohald sias: An iater.<br />
dm aprl mve dy. oMR d Cwr 7:1U Mar-Ap. IN.<br />
»o. udIu~ Ce.um7 P~Ibam Pvo d, 19o1-20. s replmd for the adia<br />
Siute auid d H b ihe DhMl d a~d, d~ l ud B ,~ la.dl<br />
- Ualverity,. booion. IN. Jime ^1I.<br />
1l. NMJaml Ct~ br Habf Sa~t DblU Deys. Vital mad Hasth Sits<br />
da Pubaddb Sedrs 10. No. 9. WaMbla,. DC: UL Govemaem dat.<br />
ins O~ 974.<br />
S32. U.& U of the Cesmm Cme~ o PoptdWo: q7O. VoL 1, C/mmet/lsla<br />
?l «p ~bu. hn 1 (ldl~).<br />
33. NiadJ C~ctur Hoe Ilib hadbl Ndia~d Ambulory MYdial Cre dur.<br />
W7: ]JB a YsMeddole. Vitl uad Hatbh Saatdi PubUclaos<br />
er kr No. ci. DIEW b. No. (HRA) -IIS, . Wmhbiga DC: US. Coy.<br />
ezurt 0dadng OEc, 1978
MANAGEMENT SCIENCE<br />
Vol. 19, No. 12, August, 1973<br />
Prinled in U.S.A.<br />
- 258 -<br />
#13<br />
PHYSICIAN SUPPLY AND SURGICAL DEMAND<br />
FORECASTING: A REGIONAL MANPOWER STUDY*<br />
A. RE[SMAN'*, B. V. DEAN**, A. O. ESOGB1UEt, V. A(OGARWAL**, V. KAUJALGI'*,<br />
P. LEWY: AND J. S. GRAVENSTEIN**<br />
Thie paper discuases the methoda and the results of a forecast for the demand<br />
for operative and obstetrical procedures anid the supply of aniesthesiologista in<br />
Cuyahoga County, Ohio. The techniques anid resulta of a ten-year forecast for the<br />
deniand for and supply of aneathesiologists and auxiliary personnel in greater Cleveland<br />
are dlicusaed. Several regression modele were used to forecast asupply based on<br />
popuilation, number of physicians, and the income per capita. The demand models<br />
wcre based onr population, age and sex distribution projections, and historical data<br />
regarding operative and obstetrical procedures. The results of these "objective"<br />
models were then compared to forecasts tunder tincertainty geznerated by a panel of<br />
experts tU-ing the Delphi Method. Alternative states of healti care delivery were<br />
investigarted and irnplications for future aimiastlhesiologist maanapower requiremenlts<br />
detailed.<br />
1. Introduction<br />
It is gcnerally believed tlhat medical manlpower availability is a kecy element in the<br />
never ending struggle to solve the nationi's healtl problems 113]. Matry regions are<br />
facing severe shortages of health care professionals. There is general agreement that<br />
persomnnl qualified to administer anesthesia are badly rnaldistributed; somce believe<br />
tbat cven today many thousand anesthesia specialists are lacling. W\itlh the average<br />
agc of anesthesiologists in thc nation bcing forty-five years and an attrition rate of<br />
30% over thc next 10 years, a definition of what constitutes a properly balanced<br />
supply and demand becomes important. In Cleveland n group of coneerned anesth(!siologists'<br />
addressed itself to the problem of current shlortages in anesthesia manpower.<br />
Under a grant from the U. S. Public Health Servicc, 2 the present authors in<br />
cooperation with the Cleveland Committee on Anesthesia i\[anpower critically iavestigated<br />
the current and future status of the anesthesia matnpo\we(r situation in the<br />
county. Specifically, the problems of supply and demand of annestlcesiologists ia<br />
Cuyalioga County, Olhio up to 19SO wcre investigated and models were developed:to<br />
analyze these problems.<br />
2. Supply Model<br />
The number of anesthesiologists in Cuyahoga Courity in the year 190S can be forecasst<br />
by considering different supply mnodels. These models are esseritially recgressiona<br />
niodels. PaLranieters for tíhese models were, estima:ted usilg data fromt 1963(-1969. Ia<br />
the study by Dougharty [4], a set of regression models for the supply of plhysicians in<br />
the state of Arkansas was developed. The models proposed lhere correlate thle number<br />
of phl sicir:is to the population and per capita income, wvith the data obtalined fronm the<br />
* leceived Junre 1972; revised October 1972.<br />
** Case WVestern Reberve University, Cleveland, Ohio 14106.<br />
t Georgia Instittute of Technology, Atlanta, Georgia 30332.<br />
lt alliol College, Oxford, I:nglarid.<br />
' !)irect .,". Anaesslhesia D)epartmentsl in ninre major Cleveland lIospital:i.<br />
sCuntra('t Nos. NIII 70-4033 a:id NIII 71-4022 (Anesthesi¢logy N:tlilpnwrei<br />
Period Jai'uaary 1, 1971 to Marc'i 31, 1972.<br />
Problerias) for thit<br />
('opyriglt ) 1973. Tlhe InatitutL' 1ft M iarneuent heieuces
- 259 -<br />
REISMIAN, DEAN, ESOOBUE, AGOARWAL, KAUJALGI, LEWY & ORAVENSTEN ;._<br />
nation and the state. Since our work was confined to supply predictions for Cuyahoga<br />
County, two translateral prediction approaches were possible. One could either relate<br />
national figures first to the state and then to the county or relate the state figures<br />
directly to the county. A basic hypothesis in this study was that a relationship exists<br />
between the numbers of anesthesiologists, surgeons, and physicians in general.<br />
A. Model I<br />
This model considered population and per capita income as the most important<br />
factors which affect the number of physicians in a given region. Iistorical data on<br />
the number of anesthesiologists in Cuyahoga County wvere not available. However,<br />
the ratio of the number of anesthesiologists to the number of physicians was approximately<br />
constant lor the state of Ohio frorn 1963 to 1069. 'The average ratio was 0.038,<br />
with a range from 0.036 to 0.040. We therefore accepted 0.038 as a reasoxiable ratio<br />
for our projections and treated Cuyalioga County as a microcosm of the state. In<br />
Nlhdel I the nutnber of phlysciauiis ini an. year was assumed to be related to per capita<br />
inicome and population exponentially. Specifically, if P(t) = number of physicians<br />
in year t, S(t) = population of the county in year l and 1(t) = per capita income of<br />
the county in year 1 then P (t) = AS (t)"'I(t)cL, where t = X-1900 (X = 1960, 1961,<br />
1962, ... ) and Al, B", C, are equation constants. Note that both population and<br />
per capita income were assumed to be related to year 1. Choice of base year as 1960<br />
is irrelevant and does not change the results. S(t) = aIbl and l() = ab' where<br />
al, b1, a2, b2.are equation constants.<br />
D. AModel I (A )<br />
This model predicts the supply of physicians; assuming an exponexntial relation between<br />
the ratio of per capita income of the county anud the per capita income of the<br />
nation. If<br />
P(t) = number of physicians/1000 population,<br />
I(t) = (t)/(),<br />
I.(t) = per capita income of the county in year t,<br />
1. (t) = per capita income of the nation in year t,<br />
then P(t) = Aj2l(¿)B, A 2, B2 are equation constants. It was assumcd that I (t) is<br />
exponentially related to ycar t, I(t) = A 4tb ' .<br />
Now if D (t) = number of physicians iii the county in year t, and A (1) = (population<br />
of the county) X 10 a then D () = P(t).'A(t).<br />
The population of the county vwas assumed to be linearly related to year t, as<br />
A (l) = a 3t + b3, where a3, b 3 are equation constants.<br />
C. AfMoel II(B)<br />
A similar model can be built wherc the estimation of the supply of physicians was<br />
from the state to the county which is called Model II (B). If<br />
P (t) = number of physicians/1000 population,<br />
I(I) = I()/,(),<br />
I1 (1) = per capita income of the county in year 1,<br />
I.(t) = per capita income of the state in year 1,<br />
thien, P (t) = AI (l)''"' :Ld D (t) = 1, ( (). l).11<br />
The remaining symbols are similar to those used in Model II (A).<br />
D. Model III<br />
In this model the supply of pliysiciaiis was assumed to grow expollc,,tially with<br />
year t. If P(t) = number of physicians in the county in year t aud 1 = X-1900 (where
ANESTHESIOLOGISTS<br />
PHYSICIANS<br />
- 260 -<br />
PHYSICIAN SUPPLY AND SURGICAL DEMAND FORECASTING<br />
·-"- DATA =j FORECAST -<br />
192 5000 MODEL<br />
MODEL n<br />
í84 4800 4184S00 - MODEL m<br />
176 4600 40 - MODEL<br />
68 s 4400<br />
160 4200.<br />
152 4000 -<br />
144 3800 -<br />
136 3600<br />
128 3400<br />
1963 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80<br />
CALENDAR YEAR<br />
Fiouni. 1. Supply of AnIesthesiologists/PhyYicians in Cuyahoga County up to 19SO.*<br />
X = 1963, 1964, 1965, - ) then P(t) = Al4e" where A4 and 1¡4 are equntion constants.<br />
The detailed analysis of the models is reported by the present authors in 161. The<br />
results of thlese models are shown in Figure 1.<br />
It can be seen from the graph that Model III forecasts 182 anesthesiologists, tho<br />
highest, and MIodel II (A) 164 anesthesiologists, the lowest estimate. The predictions<br />
of Mlodels II(B) and I with 170 and 177 anesthesiologists fall within these values.<br />
The estimation based on time gives the highest, those based on per capita income, thc<br />
lowest value.<br />
Accordinig to these models, in 1980 there will be a 12% to 24 % increase in the number<br />
of anesthesiologists since wec counted 147 in 1969 in Cuyahoga County. Thce average<br />
amnnual rate of incrense in the number of anesthesiologists is 2 to 3 ancstlesiologists<br />
per year.<br />
3. Age-Sex Specific Demand Model<br />
In order to leffectively plan for the supply of manpower aLLd other resources it any<br />
professional discipline, it is necessary to have a means of assessing the future demand<br />
of the variables of concern. Manpower demand in any discipline over a period of<br />
time depends on demography, industrial mix, manpower utilization, and cconomic as<br />
well as social factors operative in a given comnmunity. Since these factors are subsumed<br />
in a model predicting incidence of operative procedures in any arca, any<br />
meaningful projections of the demand for anesthesiology services in Cuyalhoga County<br />
would normally include elaborate consideration of the demography of the area. This<br />
part diseusses the development and application of a deremand model for anetsthe.sia<br />
Personlrel bas :d on the demAnd for surgical procedures. In particular, an age-sex<br />
Specific m odel is considered.<br />
* Th app:trent discoittiruity at 1969 occurs hecause diffcrent regression mnodels werc uaed on<br />
the }listorical data from 1963-1969.
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REISMAN, DEAN, ESOGBUE, AGGARWAL, KAUJALGI, LEWY & ORAVENSTEIN l<br />
Let the populatioól be grouped by sex and age distribution, where the age groupl<br />
0-4, 5-9, ... , 80-84, S5 years and over are represented by j = 1, 2, -, J - 1;<br />
respectively. A total of 18 age groups were considered. Tlie surgical procedures weri<br />
similarly classified using the standard 16 international codifications (i.e., Neurosur.<br />
gery, Opthalmology, etc.). The following matrix of demand model was then devel.<br />
oped. ''<br />
Let A' be the matrix of surgical procedures for males and A' be the corresponding.<br />
matrix of surgical procedures for females. Tlifs distinetion is necessary since past stud.<br />
ies, (1] for example, indicated differences in demand indices betiween the sexes. The,<br />
cells of the matrix [alj] then give the coefficient of demand and represent the number<br />
of procedlures of type i performed on males. i¡ age groulp j in Cuyathoga County.in<br />
1970. Similarly, cells [a{jl represent the number of procedures of type i performed on<br />
females in age group j in Cuyahoga County in 1970. In performing the calculations<br />
we must consider all values of i and j where i - 1, 2, ... , 16, j 5 1, 2, ... , 18.-. .<br />
Let b" be a vector giving the distribution of males in Cuyahoga Counity in 1970 and<br />
hJ be a vector giving the distribution of females in Cuyahoga County in 1970.<br />
Thus, b" number of males in age group j in Cuyahoga County in 1970, and<br />
bJ = number of females in age group j in Cuyahoga County in 1970.<br />
Similarly let d", d t denote the vectors of projected distributions for males and<br />
females respectively in Cuyahoga County in 1980.<br />
Define a vector pw as the ratio of the projected male population by age group in<br />
1980 to that in 1970 in Cuyahoga County. Similarly define pl for females. Thus,<br />
(1) pj' = d="/bf'<br />
and<br />
(2) p/= d //bl, j = 1, 2, ... 1S.<br />
We must then compute a vector (X) = (X'4, X') defined as<br />
(3) (X')= =[A(pj"),<br />
(4) (X) = [i,' (p/),<br />
wvhich was obtained by direct matrix multiplication.<br />
It is clear that (Xj) gives the projected demands for surgical procedures by males in<br />
Cuyahoga Countty in 1)SO, with (X/) giving the correspondirng Iprojectioiis for females.<br />
Thus, X"' gives tlie projected number of surgical procedures of typc i to be performed<br />
on males in Cuyahoga County in 1980, and X/ the similar projections for females.<br />
If we define N" as the total number of surgical procedures required by males in<br />
1980 and N' thie corresponding figure for fcmales, then N"' = 'I[ X"'" auid N' =<br />
-!, X,/, hence NV = N' + N / is the projected total number of surgical procedures<br />
required in Cuyahoga County in 1980, if it is assumed that the current demand patterns<br />
continue till that time.<br />
The data for matrices A"' and A l (follo win¡g pages) wcre collected from tlhe QUEST<br />
division of Blue Cross of Northeast Ohio. The data cover 79% (estimated) of all<br />
surgical and obstetrical procedures performed in 1970.3 This factor was used througlout<br />
the initial phases of the calculations and then adjusted accordingly to accoftut for<br />
its partial coverage. The matrices A' and A' are shown in Tables 1 and 2 respectively.<br />
The data for vectors b' and b t were obtained from [10]. Thie vectors d ' and d t giving<br />
a In Nurtiheat Ohio.
- 262 -<br />
PHYSICIAN SUPPLY AND SURGICAL DEMAND FORECASTING<br />
:he age-distribution of the population in Cuyahoga County in 1980 were not readily<br />
vailable from any known source. Consequeutly, estimates were obtained by comparing<br />
tlie population distributions of Cuyahoga County and the whole U.S.A. Data<br />
;rere collected from [8].<br />
Twvo types of projections from this report, namely Series B and Series E, were<br />
rniployed. The basic difference between these two projections is due to the assumption<br />
under Series B projections of an average of 3.1 children per female iin the popuistion<br />
and for Series E, an average of 2.11 children per female. Employing these two<br />
projections leads to two types of results for the expected number of surgical procedures<br />
for botlh the male and female segments of the county.<br />
Statistical tests were first applied to the null hypothesis: "Thic distribution of the<br />
population of Cuyalioga County, by age and sex in 1970 was the same as for the U.S.<br />
in 1970." The null hypothesis was accepted on the basis of Kolmogorov-Smirnov<br />
Nonparametric test and Chi-Square Goodness of Fit test.<br />
'lhe vectLmo p'" and p/ were calculated using relations (1) and (2), and lthey are<br />
:hown in Table 3.<br />
The total iiumber of surgical procedures in 1970 in Cuyahoga County for males Nias<br />
51,199 and for females (including obstetrics) 96,229. Hence the total number of procedures<br />
for both sexes was 147,428. The estimated demand for surgical procedures for<br />
males in 1980 is 57,666 by Series B and 55,941 by Series E projections. Similarly, the<br />
,stimated demand for surgical procedures for females in 1980 is 116,041 by Series B<br />
and 114,606 by Series E. This estimation predicts an increase of from 9 to 13 percent<br />
in the surgical procedures for males and an increase of froin 19 to 21 percent in surgical<br />
aud obstetrical procedures required by females ia the county. hlie results of this<br />
analysis also present data on the projected number of procedures for each surgical<br />
category up to the year 19S0. These values are shown in Table 4.<br />
Th'le models thus provide us with the demand figures for Surgical Proectlures for<br />
cach category of surgery. While these figures are interesting in their own right, the<br />
greater aim of this study wvas the derivation of the number of anesthetics rcquired by<br />
the population in thc county in 1980. Consequently, to obtain this number, we proceed<br />
as follow-s:<br />
Let a¡ = the conversion factor giving the number of anesthetics required by the ith<br />
category of surgery.<br />
Rational estimates for the values of ai, i = 1, ... , 16, vwere obtained froni [21 and<br />
are shown in Table 4. The total number of 132,575 anesthetics in 1970 was then computed.<br />
According to [71, there were 149 anesthesiologists in Cuyahoga County in<br />
1970. This implies that S90 anesthetics werc performed on the average by an anestliesiologist.<br />
Using the above conversion factors and the precomputed projected number of surgical<br />
procedures, the number of anesthetics estimated by Series B forecasts in 1980<br />
is 156,227. Under these assuniptions and assuming identical workload in 1980 as in<br />
1970, the estimated number of anesthesiologists NA demanded in 1980 i¡S given by<br />
SA -Number of anesthetics in 19S0/<br />
Number of anes thetics per anesthesiologist = 176.<br />
Similarly the number of anesthetics estimated by Series E in 1980 is 154,824. -lence<br />
the nu,L_ -:- f anesthesiologists demanded in 1980 is 174. Thus tlie assumlption of 3.1<br />
children per female in 1980 as opposed to a figure of 2.1 accounts for a diffcrence of<br />
two aunesthesiologists dem',rnled ini 1980 as provided by thcse niodels.
- 263 -<br />
1350 REISMiAN, DEAN, ESOOBUE, AGOOARWAL, KAUJALI, LEYV & OGIAVENSTEIN<br />
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- 264 -<br />
PHYSICIAN SUPPLY AND SURGICAL DEXIAND FORECASTING<br />
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- 265 -<br />
REISMAN, DEAN, ESOOBUE, AGOARWVAL, KAUJALGI, LE\WY & GIIAVENSTEISi<br />
TABLE 3<br />
Ratios of Prcjected ¿Male and Female Populalion by Age Group in ':<br />
1980 to that in 1970 in Cuyahoga County<br />
Ma-l . Ytm.ls '.<br />
Age rup * 1
- 266<br />
PHYSICIAN SUPPLY AND SUIRGICAL DE.MAND FORECASTING 1353<br />
4. Conclusions<br />
Both the supply and demand models presented above are primarily projection<br />
,dclIs and the results can thus be compared. The demand for anesthesiologists under<br />
rreat practices has been predicted to be from 174 to 176 by 1980. The range for the<br />
.,pply of anesthesiologists in 1980 has been estimated to be from 164 to 182. Tihe<br />
;iults for the supply level are somewvhat less than the demand that is expected to<br />
1jst for anesthesiologists in 19S0.<br />
The main limitation of the above models is that they neglect the etíects of techno-<br />
,qical, legal, ethical and economic changes. It is, however, conceivable that these<br />
etors would influence the supply of anesthesiologists and the demand for surgical<br />
:;*ccdures ald hlence the demand for anesthesiologists ini 1980.<br />
To incorporate various states of nature that cuuld conceivably occur ten years<br />
:.nce into the prediction for the desired level of anestlhesia personnel, another model<br />
i iorecasting demand under uncertainty was constructed, which is reported in detail<br />
,1)i}. In that model, the subjective opinions of a panel of cxperts were used. The<br />
n;nel included individuals affiliated with a representative group of iistitutions or<br />
.ganizations, and having expertise in all areas that have a bearing on the problem<br />
n.der consideration. The panel was provided with factual data and information ob-<br />
,ined from the supply models. Tlrough several successive rounds of a DI:LIHI<br />
*.ercise, consensus of the experts in the health care area was reached on a set of<br />
.iestions concerning the future. The questions were coacerned with the following:<br />
:.e attrition rate among anriesthesiologists; the probabilities of occurrence of various<br />
aures over the next decade iii regard to tihe quality of aeasthesia cure and the num-<br />
:.r of anesthetics per capita; thec perceived requirements of anesthesia personnel<br />
*ith the change in the quantity of anesthesia care assuming no change in the popula-<br />
'.ju and the number of anesthetics per capita; and the possible uses of the new .class<br />
anesthesia persorinnel currently in training at Case West&en Reserve University<br />
::d elsewlhere. Based on the results of thce DELPHI certain predictions were made.<br />
was observed that in 1980 there will be an estiniated need for about 50 per rent<br />
:7,re anesthesiologists, about 50 per cent more anesthesia residents in training, and a<br />
ficienit number of trained nonphysician personncl in anesthíesia comprising a work<br />
't' of about 70 in 1980. Through the DELPHI exercise, the constraints thlat con-<br />
.ibute to thegap between current and "ideal" nianpower levels in anesthesiology were<br />
., identified and ranked in order of their importance.<br />
The DELIPHI method predicted a demand for 19S0 of 35 anesthesiologists more than<br />
' mraathematical projections. A high demand would exist for anesthesiologists if ali<br />
mproved level of health care were provided by 1980. Thc DELPIII model considered<br />
':i aspect explicitly anld in fact reaclied a consensus on the figure of 0.57 as the<br />
:robability for improved quality of health care with 10 per cenit inere:ase i the<br />
-umber of anesthetics per capita by 1980. The projectioin mnodel, on the otlher hand,<br />
=ade the preilictions under the current state of health care delivery, hence its predie-<br />
'ions are lower than those obtained through the' DELPHI.<br />
Acxxs>, .. l;.%t:xNT. .. ThI e present work wasl stipported under cointract a gr.iit, nid iide.lo .vailavbI?<br />
.:ughi N'iI 70-4033 :rild NIli 70-4002. The Ruthiors aire greatly indebted tu IDrs. J. P'otter, N.<br />
-Piero, S. Katz, S. Ko'v:ac, II. Iretlinhmer, E. Malia, 13. S:nlkcy, J. Smart, J. Viljiern; all Inelil-<br />
.t u lihe CleveImld C,ímilxittee on A':o^theslilogy .Manpowcer, aln to I)r. M. lRhteCn, frr thelir<br />
lklatnee, cooperation, nnd nssistance i¡n c',ndcting this atudy.
- 267 -<br />
1354 REISMAN, IEAN, ESOGCUE, ACGGAIIWAL, KAUJALOI, LIlWY & OIIAVEtNS1E¡ú1<br />
Ilarefertnce<br />
1. AuL:iR, (1. It., "Ana Analysis of Patient Load in a Medium Sizo Community Ilospital, M.LH<br />
Thesis, Techinical ltoport 1.1028.02, DIepartment of Industrial lnginmeoring, Syracuse ITi.<br />
vorsity, Junte 1070.<br />
2. Communlications with l)r. J. Potter, Chairniiasn, DIepartment of Anestlhesiology, Clevelah<br />
Clinic, Cleveland, Ohio.<br />
3. I)>:PUt:no, N. G. :S. AL.,"The Clevelaid Pilot Program ili Aneathesia Education," Marymouat<br />
llopital, Garfield Heights, Ohio 44125.<br />
4. I)ovHAHRTY, L. A., "The Supply of Physiciana in the State of Arkansas," Rand, l1Mq3i4 ,<br />
APC, August 1970.<br />
5. (ClAV,:NSew:um, J. S. et al., "Analysis of Manpower in Anesthesiology," Anealheciology, Vol.<br />
33, No. 3, (September 1970).<br />
(. (iiAV:NaST:lN, J. S. et al. "Analyais amad Forecasting of Anestiestia Matapower in Cuyahoga<br />
County, Ohio," Techinical Memorandum No. 259, I)epartment of Operationa ltcéeareh, Car<br />
Western lteserve University. Mareh, 1072.<br />
7. " lealth Itelated I)ata," Nortilheat Ohio Regional Medical Program, Part 11, Sections.V, VI<br />
antl VII.<br />
n<br />
4. "Popllati o<br />
Is-timnates and Projectimns: Projectionri of Lilo Popildationn of the United States<br />
by Age and Sex, 1970 to 2020," U. S. I)epartment of Commerce Service, P-25, No. 470 (l#-.<br />
vcmber 1071). " '<br />
9. It*:l*M*.\N, A. et al. " Analyai anId Codification of Pro- Lird Prwt-Operativo Anetlhesia Related<br />
Tasku," Tochniical Memorandum No. 229, Department of Operationis Itcsearch, Cae<br />
Western lReserve University (June, 1971).<br />
10. " Recport of Anesthesia fManpower Coinmittee," New York State Society of Anesthesiologist'<br />
Comrmitteo on Total Anesthesia Care, 1970. -:<br />
11. "ttatistical Abstracts of Ohio-1909," Econoinic tResearch I)ivision, I)cvelopment Depart-.<br />
menot, State of Ohio, 1970.<br />
12. "Statistieal Abstracta of the U.S., "U. S. Buroeau of Census, 90th Edition, 1909.<br />
13. ST:WAUT, W. H., "Manpower for Dotter Hiealtl Services," Public Heallh Ieport, Vol. 81, No.S<br />
(May 1966), pp. 393-396.
- 268 -<br />
A Spatial-Allocation Model bfor Regional<br />
Health-Services Planning<br />
,Villiam J. AL-:rnathy and John C. llertshey<br />
Stanford Unwersi*y, Staniord, California<br />
(letccivc~l A\utgust 12, 1'971)<br />
In planning for health services, the need arises to determine the location,<br />
capacity. and number of health centers for a geographically defined region.<br />
The present paper formulates this problem in a form convenient for solution<br />
and presents results from the model to clarify some important aspects of this<br />
allocation decision. The planning region is assumed to consist of geographically<br />
defined subareas or census blocks, of known location. The population is<br />
stratified in such a way that each stratum exhibits relatively homogeneous<br />
patteras of health-care utilization. The model characterizes the effects of<br />
center locations upon aggregate utilization and utilization of individual centers,<br />
sad gives optimal locations of centers with respect to several alternative criteru.<br />
An example illustrating computational feasibility and the implications<br />
of various criteria for the location decision is presented.<br />
HE PROBLENl, <strong>OF</strong>' determining ipatial locatioxns of primary health-care :enters<br />
for a dispersed population is an important issue in primary health-care planning.<br />
This paper forniulates the problem iii terms oi four different criteria. 'The importance<br />
of accepting census statistics as .source data is recognized in the formulation<br />
·and in the choice of optimization procedure.<br />
The distance from individuals in a community to sources of care is a recognized<br />
' ' t<br />
barrier to utilization." "1 Several types of decay functions have been proposed<br />
to describe the inverse relation between distance to medical facilities and utilization<br />
·M these facilities.l " '"- Recent research by the authors analyzes choice behavior<br />
among facilities when several facilities at varying distances are available. z'l<br />
It ¡e<br />
demonstrated that the influencc of distance upon choice behavior iN much stronger<br />
tairn ik the influence of distaince ulpn overall utilization.<br />
In addition, it is well known that demographic, socioeconomic, and health-<br />
*-tatus factors all influence individuals' medical-facility utilization. Strata that are<br />
?differentiated by these factors show different utilization patterns as a funetion of<br />
distane .12.'," That ,''I , is, distancc is a larger barrier to utilization for ~some<br />
strata than for others. Substantial progress has been mnade in understanding the<br />
e oomplex interactions of distance and socioeconomic variables. However, a method<br />
for using these interactions to suggest alternativc locations of medical facilities has<br />
not heretofore been developed.<br />
A frequently stated goal of regional primary-ihealth-care planners i¡ to allocate<br />
facilitie to locations in sueih a manner os to provide as much of the primary care<br />
Idemanded by the population as possible. Y'et this may conflict with other goals.<br />
For example, if the health planner maximizet total utilization, centers may be<br />
' placed closer to areas that contain large numbers of people for whom distance is a
- 269 -<br />
William J. Abernothy and John C. Hershey<br />
stronger barrier to utilization thau to areas with populations that are more mobile.<br />
Such an allocation of centers may be far from optimal in terms of thc goal of mini.<br />
mizing the average distance patienxts must travel for cach vis4it.<br />
The point is that alternative objectives i¡n thc spatial-allocatiosi problem will<br />
often eofliict. Any proposued louationie of health centera mnust be atudied i¡s Il ,.<br />
light of cach objective.<br />
This paper pres*enta a model that can a.rist a hcalth-.yístemn planncr in dlett.'r.<br />
mining the location and capacities of a specified number of health-ciLre (.'iuirs<br />
within a region in a'cord:uiec witi ritated criteria. Thc formulation reli(e4 ui,t,<br />
0c,',wuS df nmakilg tnruleTffs among multiple objective.s is almo explol*rld.<br />
Ans e xamphl olTerinig ,mnutirical experienice with the model ia givwn that
U<br />
u<br />
- 270 -<br />
Regional Health-Services Planning<br />
.:<br />
t:<br />
.zW<br />
9<br />
.i<br />
ti:<br />
¿C
- 271 -<br />
William J. Abernathy and John C. Hershey<br />
SUlppl>se ; prilmiary care acilities (or ueniters) r'e [O ebc located in the area. WVe<br />
dein,. dist:aince betiwveen two points it tihe ar'a tis the rertangular .separltion It ll,.<br />
iumni of the vertit.al arid hlorizonital distanees) betwee¡n the tswo points. Thir is<br />
,'nlr. Iiit inorf rl valid l1h:.i Ihle dirret, distani e I)\ !we', 1lw twvo pointis. siart, i¡<br />
¡livitidualsl -will tr:ivel iiglh\\tways i tihe tegelmr l per value of the power hlas iol Iue)ct empirically establisheid ior<br />
the general eaise, and various valued are reported.1"`1 The present formulation assumes<br />
a power of 1 for simplicity. The numerical method used for assignting fatilities<br />
to locations places no constraints on the use of different values, should they 1íe<br />
appropriate for a particular application.<br />
Wlhen more tllha osne renter is included withit a planieitg region, tlie ¡ormula tion<br />
inust be extended to recognizc the effect of distane on bioth the user's choice of a<br />
parti'ular ceiter among those available and the chalinge iii overal3 utilization thiatl<br />
r.sults wh(.n nu,'iío crínte í lrs ar: availal>l. 'l'lu .ecffet ofl distac, oa"c it" iliza.ioa i. bIt t<br />
meswured iii term.t of the proximity to thie clo.sest ceniter. ''lhe nminimunim dist:ilíec<br />
from a cen sus block i to a center is defined as bi niln,-i, ... .. b,,.<br />
A us.r's choice of a particular cente.r from among tliose availaltle is stron gly i¡iflueticed<br />
by tlhe proximnity of the cent.er to the use'r i rlatioí to til, proximit y ofC<br />
* tilher :',.te.rs. Rtece!int re.s.arcrh by the presi.nt tiittlLíori sh,o' tsli.it a regressjim liiO
- 272 -<br />
Regional Heclth-Services Planning<br />
distance can explain over one-half of the variance in the percent of all families that<br />
choose a particular center. tl t In the present nodel the choice of a particular center<br />
k by individuals in census block i is represented by the probability Pn.. Thiis probability<br />
is conditional upon the specific spatial relations among centers. Thus, if<br />
uij is defined as the total number of visits to center k by individuais in stratum j<br />
in census block i, then<br />
uiik Pin ije//( 1 + dib ). (:3)<br />
The particular probability distribution function tihat is ut¡sed in the numerical<br />
examples discussed later is as follows:<br />
Pa=- 1/[ _,'k' (bi/b,,) ]. j (b/l>bk). (4)<br />
This .tari tliat r the pirol)bility of c hoosiing a I)articular center k is a funetion of ithe<br />
distance to center k relativc to the distance to the nearcst center, or bi/bk. Theo<br />
probability function is formed by normalizing thiis ratio by the term k a" ( biJb),<br />
to satisfy the constraint .,- _ Pk, = 1.<br />
The specifii functional relations that will bhest represent patient behavior in¡ the<br />
choice of a facility j
- 273 -<br />
William 1. Abernothy ond John C. Hershey<br />
maximize or minimize a specified criterion.<br />
tives. for a regional planuer are apparent:<br />
Several reanonable cla~.,es of objev.<br />
1. tMa.o.niúc utilizatiopn. Mlaximize the total utilization of prinary health<br />
services i¡u the region, i.e., m:L(xU.<br />
2. JlinimUize dlisiace per capita. Tlhiu criterion mighlt be represmalted i¡ two<br />
differenit -wa:ys: ta) .\Minimize the average distaxnce that cucrlh individual in the,<br />
comminunity mu.st travel to reachi the enter of choice. (b) .\linimize the' averag,,<br />
dista.l'e per :apita t ttlihe (lo.s-t te iter. Tlhe latter alternative is choiiine for su.l<br />
~.lK'uent an-:lysis. .\[athenumti('ally, tlis t.ales the form minl( E.': :,' )./b"n<br />
:. .l litimiz,. i slitlce per c/ i. ,tinmizi the average ix.r-visit travel di.t:mn",<br />
to tlic n(arest eenrter, where all visits as computed in equation (2) are inchlulld.<br />
i.e.. miáiZ:-L £ - . m i,b/l'). i An alternative statemenit of thi.i ,riterion is t(i<br />
minimiz, thi- tvf.r:ige li.st.l:,. trav.hvdil IK r visit to thel u.ier's e, t(,Lr of choice. TI,.<br />
lirst vertsion i.s 'omsidre(d preferable for nmost applications, howvever, imice tui¡<br />
minnimum reqluired distanve exlusçive of c*hoiec better represont.i the effeet of di.tante<br />
ea a barrier.<br />
4. .lin&iilize percent deleyralalion in iutilizaíion. Thisi eriterion minimize.s ¡hei<br />
averag
- 274 -<br />
Regional Heolth-Services Planning 635<br />
requiren:mitas, a in e.:haaliasm for exanliniing tlic' in:renmental gaitis to be expected fro)m<br />
adding ad(litio(:: l e(enter,. alid a ii'i:1s to e)xplore th(<br />
tívc cntriteria upn solutions.<br />
it(ierentia:l (ffetets of alterna-<br />
Suppose thatl the hcalth planner can) select a criterion, atnd wishis to determine<br />
the optimal loc1ationri of G primiary caree ciitters. wliere O· cea:u r:tg. frLrom on, upa to<br />
some maximum fiasible ¡number. (If somne trieuters :air(,ady exist iti thc region, lle<br />
may want to hiolhd these illociations constant anil conisider only the optimal locationis<br />
of additiot.id centers.) By using the model, lie eaní compare the expected incremental<br />
gaiiis in thie c-riterion valuti for ea:h ah:itiotiual center. If tlie lhoicje :umong<br />
sevcral olthjttives is unia::tr, lihe prorlss of allor:nting Celiters can l)e relp.:ated to<br />
maximize eacll objective. for vach value of G. This facilita:tes a compari4on of<br />
different locations in terms of their relative erfec:ts on muiltiple objectivec.<br />
Suchla :a us( of thi( mod(el is illustr:at(d by 1lW( h xa tinl)el it thie followiltg ;se(liot.<br />
The ,i))ln'ai':atl restilts iar. o|r t:'hi):l for a conill)letc, ont-lille, ilnl era:ctive, FUILTUAN IV<br />
version of the mode-l, programmein to be suitable for several hundred census blockli4,<br />
and up to 20 centers and 8 substrata. The program determines the values for all<br />
TAISI.u.: 1<br />
UTiI.i.%iTioN C'iA.ll.\ ¢'TIr:tlIl'-T.^ 1O:A\II STIIA.\rUM<br />
Utilization rate at immediate proximity<br />
|litgh Low<br />
BIarrier effect<br />
tanee<br />
f dis-. Stl. ratum l j<br />
v, -5.2<br />
I¡ .Slratium j-4<br />
& ¿=l1.9<br />
d -. O.0005 d4-0.0008<br />
lligh Sratrtitmjj=3 St rat tiau j -2<br />
; =eli.2 t a2 .1<br />
: · ,Z,,o d.i lai<br />
115<br />
four criteria described above although only oune is optimized at a tinme. wse of the<br />
model provides understanding of the problem and insights into the impact of various<br />
cnrteria on the solution in a hypothetical example.<br />
AN EXA.IPLE<br />
AMsuYE TIIAT health care centera are to be located withii the regiom d.,cribed itn Fig. 1.<br />
The regiotl has 4 strata, with vi and di a.s given itn Tanhble 1. Strata 1 and 3 have manrkedly<br />
higher utilizatiotn rates al imtme
- 275 -<br />
William J. Abrnarthy and John C. Herhshy<br />
It is uieful to explore tile ¡inplications of thc variouu criteria for a given number of he:i(1h.<br />
care. centeor and then to examine the ellect of increa.sing the number of centers. Thle IfTawt<br />
of alternative criteria is the most obvious when one center is i>ositioned to satidfy the ent ire<br />
region'l; requirement. Figure 2 liows tlhe three differeltt locationa for onlul center that :ure<br />
T.,BLI:, I1<br />
l.,ATrlON. I.t)uXU, .xi)> POPUL.ATION uO C';:.SU 1B.ucLrs IY ¿VT.\lAT'M<br />
No. Coordinates Radius<br />
-1U.0 1 1.2 1.0<br />
2 t - I Iu.0o 12.5 1.0<br />
: -S.-8.7 1I2.(l i.0<br />
¡ -'. 4',j 1 1O.O 0.7<br />
, -11.5 10.4 1.0<br />
Ei -12.0 14.8 2.0<br />
7 -7.5 14.0 2.0<br />
t -6_. 3 i 10.4 2.0<br />
9 -10.2 7.3 1.8<br />
10 -13.7 1 9.1 2.0<br />
1 -1.2 11.5 2.2<br />
12 -3.2 j 3 5.0<br />
13 -12.5 4.2 1.8<br />
14 -12.0 -0.3 4.U<br />
15 4. ij t9.0 4.0<br />
i -8.3 -5.2 3.5<br />
17 i 2.7 -2.0 1.7<br />
I18 3.0 1.2 i<br />
2.0<br />
19 5. -3.7 2.0<br />
20 1 0. -4.8 2.0<br />
21 It.4 11.3 2.5<br />
22 ' 20.3 5.7 3.5<br />
!3<br />
2>4 j<br />
2 11.5<br />
10.9<br />
3.<br />
1--5.8<br />
1 5.5<br />
! 4.0<br />
25 j l.O -0.85 3.0<br />
21 ! 2.0 0.3 1.8<br />
27 24.8 --6.3 1.5<br />
't8 ' 18.0 -6.0 2.0<br />
29 21.8 - -3.3 0.8<br />
30 k2.4 -1 1.0<br />
31 22.8 -3.7 1.0<br />
32 20.6 -4.3 1.0<br />
StratunI 1 Straum 2 Suatum Stratum Slrau<br />
1O(Xi . i. 4;5 i 1;)<br />
634 1617 IX) ;t;<br />
j w33<br />
2 ;O 55<br />
1 7<br />
175<br />
! ¡? 14;x;<br />
¡0 llt ¡iuu<br />
i633 16i i (X}) .5;.<br />
1100 - ~0 130 454<br />
700 400 : 200 : »)<br />
tax,) 200 120 150<br />
ti}5 '.H1O 120 5lZ)<br />
700 T Ld0 1'25 ( ti)<br />
850 i J0 12,5 700<br />
i 512 1to o 338 j 5)<br />
44i 2i00 37 350<br />
34i2 200 1 38 250<br />
5)00<br />
iO0<br />
750<br />
112<br />
112<br />
112<br />
113<br />
113<br />
113<br />
2'25<br />
250<br />
167<br />
167<br />
166<br />
575<br />
375<br />
375<br />
450<br />
350<br />
700<br />
350<br />
450<br />
450<br />
450<br />
lU0<br />
534<br />
533<br />
533<br />
4;0<br />
275 S<br />
275<br />
250<br />
137<br />
288<br />
28 8<br />
787<br />
438<br />
537<br />
475<br />
850<br />
600O<br />
60O0<br />
6OO<br />
i<br />
.00<br />
500<br />
lictated by eriteria 1, 2, aid 3 with repeet to the three cities. The three dots indicate center<br />
ioatims; assoe~ited triangles identify respective criteria. The precise locations with resleet<br />
to the coordinates in Fig. I are given ii Table II. I)ata offeriig a comparison of each<br />
location with respect to all criteria, including criterion 4, are pIrovideti i¡u Table IV.<br />
Tlle tiree criteria yield eritirely different locations. Vhen criterion I (maximize utiliza-<br />
140<br />
150<br />
150<br />
150<br />
150<br />
350<br />
217<br />
216<br />
216
-¡' -l _ *-s 0<br />
- 276 -<br />
Regional Health-Services Plnning<br />
-50<br />
5<br />
. Center<br />
_/~ Criterion govcrning<br />
center locations<br />
O o 15 20 25<br />
gltJ1) ^^ B "'->)t<br />
\sQ~ty<br />
Location of I Center. for 3 Difzerent Criteria<br />
Fig. 2. Tlio e*ffe t úf eaeIh criterion iUpon the locatioii Of olle heaIlth *(entter.<br />
Center number<br />
I Wiil 1 I e'lter<br />
11 Wiith 2 eo.lotrs<br />
2<br />
1<br />
1ll With 3 cmleri.<br />
1<br />
3<br />
JV Wilh t ee-lhr, q<br />
4<br />
" °<br />
V Witb 5 velder<br />
4<br />
TABS L! lll<br />
.%1) SIIEUI*'fIr:IJ Mn..MEII F* ( (':XTEI:.<br />
O. c Fig. I f.,r I,,e ,.,rs ..f ('lmrdil:Ie,)<br />
Criterion<br />
(1) Maximizc (2) Maximize distance (3) .Minimizedistance<br />
utilization per capita 1 per encounter<br />
y x y x<br />
21. j11 - 3.1X) U 1.$4 1 .2 - .71) 10.1)0<br />
21.-1 -3.7 I l?. I -3.;1M) -3.3 1i .)! U)<br />
- i .U4 .i<br />
.SI) 10.4 -9.U I .10..U<br />
'2.40 -3 .1 21.52i -2.78 22.30 -3.20)<br />
-10. tIl 10.40 -10.¿¡ 10.40 -10. 0 1) 10.40<br />
3.-63 - .75 3.iO -2.80 3.i0 ! -2.80<br />
2 .» 402 .) 3.r14j t 22.00 -:J.50 1 21.23 -3.04<br />
-- IU.;dU LU .4U - IU.IU ¡u.5O<br />
IU.4U<br />
3.59<br />
11.32<br />
-2.7&<br />
- 2.25<br />
2.0YJ<br />
3.76<br />
-4<br />
3.04<br />
3.1il<br />
- 11.3.5<br />
-2.70<br />
3.00<br />
22.40<br />
3. 24<br />
11.04 l l .li<br />
ae Delermir:d ,eo.ly ftr Ihe tiran eriterico.<br />
-3.10<br />
lO.lil<br />
-3.19<br />
3.21<br />
-L )<br />
.1~
- 277 -<br />
William J. Abernathy and John C. Hersihy<br />
tiona) i , u.le, the ceniter is located near the center of C(ity C. 'G'lis is due lo the fItct thai.<br />
thi4s anra tcontains : large intuber of individuals for wlhom distutcec is a strong barrier. Aí.<br />
the satne time this choice of a locationi tends to inerea.se overall distance per capita vi-a-vis<br />
other criteria greatly, as can be seeni from Table IV. One might argue that this criterion is<br />
most equit:able, siice it favors tho*e wvhose utilization is mnust curtailed by larme travel di..<br />
ta:'nes. lowever, a cotiter :argumneit i.s thlt the resliltinig location shlift* the cost nf trans.<br />
portationi to those who are less .cansitive to lLsitance barriers, irresipective of their ability to<br />
accept it.<br />
'ihe tlird criterion (minimnize distance per enicounter) lends to a location near thi * r'net r<br />
of Ihe latriist *ity (.I). This loeat ion i¡. traduliionial hut not Ipartii.ularly equitable. ()vt.r:tll<br />
TABLE IV<br />
CH.AtA.CTV:HISTICS <strong>OF</strong> P)TIMULM ' LOCtATI.O<br />
Criterion<br />
Maximize Minimize distance Minimnze distance<br />
utilizatiuon per capita per encounter<br />
Will) I t;ml. Ier<br />
Utilizalti(,m. U i 12,29 11,07 119,572<br />
)istance/capita ¡ 25.82 18.00 1 * 1.18<br />
I)ist riceencouiter 24. 8 16.5 1 14 .110<br />
!lldex-.'- deerease ill -utiliza- 33.2% 35.4% f :..';;.<br />
Wilh 2 ('elnters<br />
Utilization, U 146,891 143,237 144,195<br />
b)istlace,ecapitu 8.53 8.14 8.17<br />
Distane/eneounter 7.39 7.41 7.39<br />
Index-%c decreae.¡ in utiliza. 21.7T% 23.4% q 22.0:<br />
tiotw<br />
With 3 Ceiters<br />
Utilizatiowl. U 155,086 154,575 155,051<br />
Distanee/capitt 5.32 5.31 5.32<br />
Distaniee enemxinter 4.00 4.94 i 4.90<br />
Index-%; decrease in utiliza. 16.9% 17.15% 1 16.915%<br />
tint<br />
With 4 C:enters<br />
Utilizatioas, U 156,932 156,000 155,514<br />
I)iataneei~'r:ipita," 4.87 4.77 4.79<br />
Diaitance/encounter 4.58 4.43 4.39<br />
Index-% decrease ini utiliza- 15.84% 1i.26% 16.567O<br />
tion<br />
tutilizaticin is the lowest with this eriterion and the pereent reduction in averuge utilizttiol, is<br />
highest (criterion 4). This third criterion is appropriately desecribwd tas a local one. That i.,<br />
it does not consi.tently represent needs throughout the region. In the present example, the<br />
optimium results from a simultaneous decrenae in utilisation in some arens and an increa.ce in<br />
uothers. .\s the center is moved away from distaince-.iensitive remote locI:tiont;, distance p er<br />
encounter decrea.es over the rasige considered. This is because utilization varies invers. -ly<br />
with, and at a higher marginal rate than, distance. At the same time, thbe center is moved<br />
toward large population unatenr so as to inereas~ utilisation at elo*e proximity. The criterion<br />
i;s analogous to the action that well-intentioned medical practitioners might take in<br />
independently locating their individual facilities-minimize the distance that their paticntl
- 278 -<br />
Regional Halth-Services Planning<br />
mwus travel. The e.'ssemtial pIoiit is thlat sirh a'l rule leads to nmuch diffcrcut re.sults tlhal are<br />
obtnine,íl with more global criteria.<br />
The .eeond criterion yield, a location tihat might be anticipated. PIer eaplitas distanee<br />
is miimiztired lien tlie center is located iii City B, betwen the two larger citieis. It ir interestinl<br />
to note that this mile, like the otlher two, tendx to locate ¡le ce eter in un area of high<br />
population ratliher tha: iii a s.par.sly Ilopilated 'elsus block.<br />
There is little difference in the effects of tihe three criteria uion locatio.as when tvwo or<br />
three eenters are allo:cated. As. lhow ti T:able i 1 for tlhe twao-reiter case, locatitu.s are near<br />
the cemiern of the two I'Lrage cities (.4 adml () for all itriteria. Siil'nil:rly witll tlinre eiEters,<br />
the! a e:msi-r.l hlly lo'ald .lr hel etr e f th rlenters l e e riles.<br />
The four-eenter ca.us, like the tione-center ease, aigain shows a distiset differece animong all<br />
tiree crinteria. This i9 depicted in Fig. 3. Three cetr are e oiiteit ly located iin the<br />
* Center<br />
/ó\15 \ ~/X Criterion governing<br />
-i C 10<br />
( \ t ) "/Ce Ce ntr O<br />
lo 15 2<br />
t tions<br />
Locotion o; 4 Centers -or 3 Di-s rennt Criteria<br />
Fig. 3. The effect of each criterion ulpol the location of four health centers.<br />
eities buit the location of the fourth one delcmlds r'ritieally on the criterion. The effect of<br />
each criterionI upon the location of thibs fourth econer is similar to the effeet of eacti criterion<br />
upon the locatiou of onne center.<br />
The diffelu.l ial effects of different criteria for hetalth -ervices tendl to dimil liu.-l the<br />
number of ceniters increa.-es. The ímpact of different criteri in a muel le&s whemí there are<br />
four centers than when there is only one. Figure 4 providei a direct comparisota of tihe<br />
criteria ai the number of centers is inraceased from one to four.<br />
The three separate graphl shown iii Fig. 4 pre.~ent the valuc of each criterionm wielm it<br />
merves uai the basis for optimizing the locatioii of frona one to four renters. Eaíh gmrapl li l.so<br />
provides a comparisaoí of this with the dlegradation in the same criteriomn measure wlen each<br />
of the other two erintearisa optimized. The eommol pauttern with each criterion ia a sigííificarlt<br />
improvement a* the ¡unmber of centers i inereaased above 1 but a marked decrease iii the rate<br />
of improvemerit a. more venterJ are added- a ntro:zg tetsdeic.y towvard dimiiishing rettirlat. to
- 279 -<br />
William J. Aberncthy and John C. Hershey<br />
Increase in distance per encounter when<br />
criteria lond 2 ore optimized (miles)<br />
o 4r 0 o<br />
(sgall.w) Jaunooua Jad aouos.!-<br />
Increase in distcance per copita when<br />
críterio lond 3 ore optimized (miles)<br />
t 2E<br />
u t<br />
eln o<br />
I 1 .<br />
~ I . Z<br />
Decreo'e in utilizotion when criterio<br />
Z ond 3 ore optimized (totol visits>x i000)<br />
P O o + , r -<br />
(o000oo1 u te.! ^ 1oo40) UO!,OZ!ll.n
- 280 -<br />
Regional Health.Services Planning 641<br />
scale. When niore fhau fotr i.e¡ter.s :te :all¿xated, thlere is little reltive inmproveimelit i<br />
any of the imtea.urcs,<br />
:uid liflerene.es among tilhe regíion-widc imeasires are negligible.<br />
The thrce graphs incliuded iii Fig. 4 deincm.trate the use of Ihe model in the inlportant<br />
aranlytic nrle of deternlining the incremental Ienefits from inrea:sin lthe nítiber of eenlers ii<br />
a region. The siecifics ouf :ai'dy.is ean Iwx varied to aicomiodaitc t he planning ie problemi at<br />
ligd. One or more centers cln be fixed in location or capacity to represFent existinig farilities,<br />
different criteria can be studlied, and miniimum or maxiiiiiini ecnter sizes can be included iii<br />
the formuílamtion. The moidel also gives vohlines bhy !.troat:s for eachl renter so thnt i¡.m'os related<br />
to liiirmln size iiol :ei a ofie ,.rf rai e:il. e:I,1w dealt wii .hit Wlilh sp'ilie refinlements<br />
can xie infrlimiruued to accolllxoditte a pIatticular plaiíning probleni, Fig. 4 illastrates the etylx<br />
of analysis that can be performed to leterniine increniental beuefits from a.dding nmore eenters.<br />
A health pl:iaitter can comniare tlie rost impllications of sugg.lted inimbers, sizer, and<br />
ocaLatioi, of center.s wvithl thl( mriiír.iiic:l Ibeefits ofof l ervie, wlhere IM-nefit, :Mr,<br />
inme.sllreu4 ii t1'm111ís (l . .l cMh 1 ritrio L :s ttilizaitiol tr',l¡'el di.,.lnse,, or per alfilat p ereent:íge<br />
decrease i¡n utilization oun a region wide hAt.-is.<br />
In the tinal aínalysis, the decision maker must decide how to weigh different<br />
objeetivw,$. No olnl( curiterion is best. Thc ultimate decision as to tlw number.<br />
capacity, aind location of health vueter moinst be hoised upoIn a broad range uf coínsiderations.<br />
However, formal analysis can be extremely useful in reducin¡g ihe<br />
number of variables that must be considered subjectively. Furthermilore, by<br />
forcing the mniodel to evailate decisions that are proposed on other hbaes, the model<br />
can serve' to qu 1itify th e'Oll(seluent s of alterliative choices for comparison with<br />
the optimum solutioins derived from explicit criteria.<br />
C(ONCLUS .ON<br />
Tg REOIOXA4L allocation problem is a central issue in research on health-eare<br />
delivery systems. This paper has undertaken to develop a method that can be<br />
applied praectically by a liealth plasittcr in bridging tlihe gap betwveen re.eareh resulta<br />
anid implementation. Emphazis is, on providing a formulatiotL tihat usefully<br />
eharaeterizes the problem within a region rather thaun on the elegance of optimization<br />
procedure!s. (As a benchnmark for eomputatioínal feasibility. cach optimization<br />
for the above example reqccuired about 20 seconds of CPU time onu an IB.M<br />
360-67.) The formulation distinguishes the separate impact of distance on various<br />
.ocioeconomie strata with respect to their choice of a particular center as well as<br />
overall utilization. Thc model can be extended to acecommodate considerations of<br />
inlxOrtaunc! ina partituil:r aPpplieatioris by eh:alngiuíg tlíi cirteria: uisl for oIplinliza:tioi<br />
autd the onllstraintls imposed ;11 the formnulationi.<br />
ACKN.OWLED(;GM'ENT<br />
RESEARCH REPOITED i11 this palper was<br />
supported in part by thé National Center<br />
for Health Services Rewtarch anid Dcvelopment, Departmeiit of Health, Education,<br />
and Welfare.
- 281 -<br />
642 William J. Abernathy and John C. Hershey<br />
REFKERENCES<br />
1. WV. J. ADEM.NATYI AND J. R. MoOORE, "Regional Pltulling of Primnary Healthl<br />
vices," .IUdicol Care, forthCloming (1972).<br />
Care S,'v-.<br />
2. - - AX) E. L.. SCIIii;M.s, ")i>tiSaIa alid llcalthl Service.: Is.U¡es of I.lilizaii¡O :andi<br />
Facility Choice for l)emographic Strata." Re.wearch I>aper l 19, Stanlford I'niver.it y.<br />
Graduate &hool of Busincs, July, 1971.<br />
3. E. S. BurVA A.> W. V t1. TA.UERT, "EvaluatioII of D)irect Conlí>uter S.arch .MellkI i";. -<br />
th( .\n.g:r i1at P'lmingiPK I 'ul)hll," m 1l ¿du. .I[Iu,('IIti»i nl¡¢., 193"?(6 1. lll, , 67.<br />
*1. A. ('IoCCo ANi 1. ALmA.N, -1eical Areas aSrvice únad 1 )istaluCes *Iravehed for l'bhyi.i;:l<br />
Cate iii WVestewn Pe.i .>ylva uia," Iublic Hcalth *iottogra:ll<br />
Service, 1959.<br />
No. 19, Ul.,S. I'ulliv 1 h:ill;,<br />
5. J. 1). FonllEs AND W. T. ZI:mImA, "EstimationI of Supernmtrket D)rawiig ')ow\r: Al. 1:\tensjion<br />
onf l.Oc:at; 'I Therry :ud I'nrii:tice," .Annanls Rl¿iontl Súi. (forthlIcling).<br />
6. W. L. G.AR-ISOX, 1). F. AI.nRLE, J. D. N¥sTUEN, AsN) R. L. MIORRILL, Sl.udies oi ¡n:l/f<br />
wag Deelopment and Geographic Change, University of Washington -'ress,<br />
Wa.hington, 1959.<br />
Seia:ttl.<br />
7. P. F. GROSH, '"rbanU Health Disorders, Spatial Analysis auid thc Ecounomics >f o[ h.ahl<br />
Facility Locatiut," Iaper presented at the 40th National Confesrreniee of the í ¡,,t; V<br />
TIOss RtUM.EAR.C SOCIET:Y oF AM.I;RICA, Anaheinim, California (Octoxber 28, 1971).<br />
S. 1'. llaggett, Locario.ial .4naludis in Human Geogragphy, St. Martin's Pre.,<br />
1966.<br />
New York.<br />
9. R. HooKE .AND T. A. JEEVtS, "Direct Search WSolution of Nutmerical and Statistical Pruo<br />
lemrs," J. .ALoc. Computing .1achinery 8, 212-229 (1961).<br />
10O. P. J. .IHLII *a.oD R. L. IC.NA..MARA, "Tlle Relationi of D)i.:tance to the l)ifferential; l ',<br />
of Certain Health Pers>onel and Facilities and to the Extent of l3ed lllnes.," Rurai<br />
Soc. 17, 261-26.5 (1952).<br />
11. R. L. KANE, 'lI)etermination of Health-Care Priorities anid Expectations amunong 1tua:1l<br />
Consumers," Hcalth SCervice8 Res. 4, 142-151 (1969).<br />
12 . . Siu. X N. i, R. L. BA3aSHua, AND C. A. NIEZNER, "The Concept ouf Disuance U:t a<br />
Factor in Acesaibility and Utilization of Health Care," .lledical Care Rev. 26, 143-1Al<br />
(1969).<br />
13. J. A. SONQUIST AND J. N. MIORG.A, The Detection of iteractiun Ejfectsa Silurvc! Re.:Lrcl11<br />
Center, University of Michigan, Monograph 35, 1964.<br />
14. W. H. TAtEr, "A Search Decision Rule for the Aggregate Scheduling Problem,"<br />
15. -<br />
Management &i. 16, 343-359 (1968).<br />
, The .Search-Detiion-Rule Approaeh lo Operalions P>lanning; Unpulblishliedl )octr:dl<br />
l)i.-,.rtation, U.C.L.A., 1968.<br />
16. J. E. WEiss AND .%i. R. GREEXLICK, "I)etermninuLts of Medical Care Utilization: Th'<br />
Effects of Social Class aud Distance on Contacts with thc lMedical Cnre System
How to determine - 282 -<br />
the optimum numbie ofoperating<br />
rooms<br />
Jay (;olhilmm. D).S,'. t(od II. A. K,,l)l)jhr' rh. r. I).<br />
11owv 'lmainy ol)icratimg§ rooiims do<br />
y)ol rcally ííe((tl? Is ii necessari y to<br />
acq
Decmand in Mintu és/Day<br />
Numnlber oi Olenj.tillg 1t l1lí1s<br />
Ca¡pacily ilt ¡ lllu.ie,' ]).i)'!<br />
Lua(di I"a' t.'<br />
A~···8 'tl-cluge aUviltf ).t \s W.,ilvd 2.<br />
:)<br />
- 283 -<br />
I. ,s(i, -/l ..... .... O.)(i )!X --- til ll>t ivel tile .i'c . '.,c ,r(,lliit (Lily d'e-<br />
:. iil .2 73.ii i:li 771-. * . tl (i,. - :;lilf :, 1 Ii t y.i itn7..<br />
thiIh ¡xd \ o hl ¡t " lul 1 r. lOl)')ratil"rZ "<br />
TJ-i; I.I' 2. J"lí s,. 1,,l , ,iil ,"it 1,'Ii '1, s "Id,¡r<br />
u I.. l ,iír<br />
displays el..í'.c " t', 'icb, ' ¡or ou . ") fm'5 (
0r<br />
1.'<br />
* SI<br />
'<br />
S5<br />
II MAND<br />
it'Al 1. D'IAYI<br />
lOAD FA':IOK 0.S'4<br />
FOR 5 ROOM5<br />
- 284 -<br />
?240<br />
').7,s C,,il9.1 ! .%917 0.?3R U.lJ'b 0./7 1.0)<br />
I 'l(:(- 1 í;t11111 ai d ,, . ' i. ,',pl u<br />
a.s a tIIW'ti>ií orf . 0'<br />
for a demand of 2,175.1. minites<br />
per day,<br />
Ci : C, -- 2:!Sn (0.R5 - 044)<br />
365 (7 03 - 0 .) -<br />
for a dmernad of 2,27l4 miimntes pc'<br />
day, almd<br />
Ci = r, -- 250C: 0 .91 - 0.481<br />
365 (23.09 -- 0.621<br />
for a demanaid of 2,372.9 minutes<br />
per day.<br />
(Conftined on Page 1.98)<br />
Disposal System 326<br />
IIstlic I,',i,í l s,'i X\i,. il' iii, , i" S ;,,,ii; l<br />
\ll l ~l;ll,-r ('(Uxlllilt. ;I : 1", u,1 .. ;"1,mf<br />
t1r:l(.1h3 . c;(.d,1h "1 .(i ip. i. "I' Id,<br />
3 i "i ',,l,, "1 ~ ,If,' I"''' ll(1 ,) ;'1'<br />
¡ l'ti\ i:llh' li'r l! '{} %IN ('i tit i"i.:i<br />
i''iii i;lth Iil. slihiiil. ,i¡l, Ii "i"l<br />
r,. i, l r ih S' \'¡l.t '<br />
ilftt ll¡i (h1'. ,111,<br />
!.,,, 1]',II ) .:!i *ij sl ¡t it ililh: I:, i l-;i " \;!<br />
-'-',' 'h.. t'llt;. .Am('ri( :11 ( ::, ( 'o.<br />
Respirator 327<br />
ilir. ;i v.hll,,( li7>i(: l. I!,u l it íl.ísh "'<br />
O"V·\ 1<br />
1- - . '<br />
.,0. :La<br />
- ZO5 -<br />
''" '' l &l 'v ic .' :l3si *iiIl('(1,- i 'i,'\\l , l.io.<br />
- (';iltii. vh.,(i"i". uIhr ;,tiiio i;iI. h;i'.,1<br />
;l. i I r li l h ';l, sisllt Illaxil)';i<br />
;dal , ', v 11 t l I ; a . .l , 1 .1 i 1h, \h m j; l(,-<br />
: 111(' ;i ;11li.¡ 1I ,li'; t' i¡,\·. ( i -';l1;s.<br />
I;lIm,'llS, ILKi',<br />
Multiple-Seating 328<br />
'I'iu ii¡' \\i í.i lí,l - -' ,ili:'. . s t!'."i<br />
S i-th r.',írí; -I.'' - Sh hu. í<br />
wa -dl.'<br />
s('atin,« ;IrrI'ill"('l*l('llt. ,~ .t('m (xOi<br />
:i1.i lia)h. n i( 'i'ly ti ,t' I'a.tri'<br />
.\Nl i.i.h.s iilh t. 3 str .. rici l'<br />
.Xladlis.sl I"tr.cihntX I.dulusrie,.<br />
Blood Warmer 329<br />
Dll, iii il. til t u,,¡t',, l(
!<br />
21 i<br />
Monitoring Syste:m 330<br />
\ Ii' '\ i, i telielíl;.l11. %!'i', e i"""'"'l"i::<br />
" ¡""I n \glil " 1"X<br />
Die11 111 il l 11s 1 i' ti11.1'<br />
i*Itijee . llleI iliít I li ' ;e ';lll<br />
,l ""il-. I th llee. .' i,' :li!lb ;<br />
i!'!:: 1l1.':li; l i1:' ;. li\ i!, ::,:e : -';l<br />
Urinal & Bed Pan 331<br />
/ ee,11',lelell'h'e te l'( .iil. Ii !l.le e l,. li.: i(.<br />
bm ('.5 - cd: ',j,:,I' e le l líle. lUei";;i. l (';e<br />
- ZOO -<br />
tlr-iilgl~ :a \l itle llal. lbamt. plrtevt lids<br />
.,ilí ,í.h , .c : i .. .1l rel lldh lie<br />
hr,.bh ,d "" dlt.1m, d 'r ¡l 4. ,," % ilt<br />
tille ilil, pliie'fd,. pl, íh';% (:oi.<br />
Recordinfg Titrator 332<br />
t<br />
\ lll :e , l' le rIle. (cc ll(lic,'4 litl;hte<br />
e' 1 l,,' i11,-1, il .1 ;ilet , e teece -.<br />
elli! e :lle . ele,*:e eti:, c 'l li ill e i ;l,<br />
: '! 'Ii .lll\ ::iti : "i , 1, .{ ,Ji' , : ,! .i:<br />
e(e l - 1 el leí . íee l * 11 1e i\ le-. % ei ! cl(í<br />
'l.l, hi'.1 ;,.c lll' ,cIf c i ''.' 1lA(i11 ll' ills<br />
tl"el ",el 1<br />
,i l, el le., Nlll. \11 n;Ih.ítli;'ls<br />
ill t'l iia 1 o I('" li-<br />
:1Si; . lut¢ini:cleil li.esIlu liii.lefil. eli-,.<br />
t $l.¡LI li<br />
Calculator 333<br />
.l : ,e:ie. ,s ,;" e ,. le 'le le, .eei l e .1.<br />
ililll: m, Ill .:Jill' ,u,(./,,~ ' ! , fl,,<br />
r",', ".,le S ¡jel l : 1- ee "; . . "1i.<br />
h1r .i I j|I :|| i i';I !l . ', , | j<br />
I<br />
;,feí í,-i,'e' ltli.,l e!S: h, :h'.i. .ll, hq, ,í<br />
Iltle ll ell , hlelS e jt e j e'. l-' l;ll:e e e l'i :-<br />
Jil",« 'i"",!, l'l'.]'.J: : i)J)'llli~llt \: llJl<br />
i 1 ' l !ll, %le'" .. :i "'t li.ll í . 1a 1 _ ' Ie<br />
i " l} y." 1 «' 1'ti a, 't ,X 1 . , '<br />
.irilt tl e,(-ie l (.;t : e :ii e le :e l. -! e ¡ : i _<br />
I¡.,lirablioriei. s it-.<br />
This new AAF horizontal Roll-O-Matic<br />
air filter is ideal for central station<br />
air-handling units or ventilating systems<br />
where headroom is limited.<br />
I _<br />
11
i<br />
Trays 334<br />
Colorful pattenis anid obllontg, rowl(l<br />
;i.!i<br />
:, tJl(r-olustati' mixiny, \.iv' [)prcsct<br />
.. .<br />
JI., 1<br />
for 105' 1'. .edíl a :;vitch lthat penurits<br />
,n,:tuu|il adjí¡stin(,lt. (3) Tinencd hydrotilerapy,<br />
with sliut-olf ut any time<br />
pl tl :i() 30 ,imtcs. ({4) 'Iit(.l (leplty-.<br />
iníg an1 auto¡ilnatie: S)lt-Mlf of water<br />
pIunip. Ille Electric Corp.<br />
Ice Dispenser 337<br />
Nhdvl XID)(;-29() t:.)il>ttlil, i í(e<br />
dlislpcscr relcas4's culbes ¡isi, ice<br />
Im 'k 'ts. pitht.l irs tlr ti!er conldtairnr.<br />
:, itliout c( ntamniril tion 1):. i,<br />
;ila Ila;iduls. ite unl it. Initlco'; up<br />
t, 3 10 pn,,,ilms of i t o cu ), ts (t: aly,<br />
;aitd ,as ;I ii isitxllil'1 iseiSl)lsihig aiud<br />
.ti>ruug (.;il;cityt tL4 275. I>nllrd>.<br />
\l:itXo(~: J, (lUil)ine-lt \!orks<br />
New AAF horizontal «-o0MATIC<br />
o0<br />
air filter. . . Comnp!etely automatic opteration<br />
- Entire unit located within plenurn<br />
i Arailílable mn 6-foot-hiqh unit<br />
The new Tvpe H lModel G Roll-O-Mlatic<br />
seits new indt.,!:y slandard for horizonial<br />
roll-tyipe filers with many advantages rolt<br />
availabli in any other unit.<br />
One of thc utniue features al the enew<br />
l ype H is the ;ibilitv ¡o change mediaii rom<br />
oulside the plenmiil tiespile ihe fact Ihe culire<br />
unit is hotised within the pleaiiii. Drive and<br />
conirols are Iocaled outside lhe plenunm aiind<br />
are readily 'ac'csible. 4ll electcical equipimein<br />
is otaiside Ihe air strea'tn.<br />
A patenied ainti-sag device provides posiise<br />
imedia seal. aik idier rolls al each end<br />
I I i-<br />
plrc idJc m,,re unifrim tracking olf me, it.<br />
l'c-vrii. ;il. id .lid e rasCtbl' Mitly .;¡l;iiI¡i.<br />
1 i0-'oial C(jl'!GCij{ki1 ¡tl C boiit'Ol lbOX i.s i(l<br />
licld wi-inoC, icqul:'ed.<br />
The ;new Typle 11 Rill-()-Nlilic. aivailaIll<br />
i .t sv¡ide .rane. of sizo .ind flutir litlercuit<br />
.ha io!itrS, . ol'cf. s lt.'ler applic.tlij<br />
I!exibiln, th.iii ne ,r lefoe.<br />
l"or clllj'1lct in,.I; l;ioII, call ytllr llei'r-<br />
)byA.,i I: i elpcrti ive; o, tite ile tr r Bullhiilm<br />
No. 24,', Robert Sloore. Anierican Air<br />
F ill er Cmpnisi. ll l c., i Central Avectie,<br />
Louisville, Kentuckv 4-0208.<br />
American Air [ilter<br />
BETTER AIR IS OUR BUSINESS<br />
I - -- - -Y-<br />
F,,r umm, , 1.,?.Y -ii -r..li .- /1<br />
t<br />
i
LITERATURE & SERVICES<br />
*ii . . i<br />
Partitions 338<br />
1,aríw1íí3il3.q the l'AI' 1;e), Jtii I)hn1.<br />
htr(rhsi!l
tiie, gency L:ghting 347<br />
,i',., .:. !l1i.' Ii 'lll)3 H'r333 345 L: )13t3';li<br />
, .. .,..." 33ll... ,{ . "im i.: !.'xi §., '. . , (. . .i, 3i. P 1.1 :'3 .1.i !. .!<br />
SUPPLIERS NEWS<br />
_ _ ag____<br />
1.d1.lr 1i.,,;()v1r::h \llulti :,; , ( :(:.. ,<br />
n--('-eh l:. . lo . 'hi: ., .<br />
4' 5t:tn('el: ,I lit':: 's Il -\<br />
::! í 5I;<br />
\.<br />
; .c .' I'i4 '<br />
3Ih"'.i . ":3 'l,, r (',,rl3., ..l
,' i6<br />
- 290 -<br />
Facility Location: A Review of<br />
Context.free and EMS Models<br />
By Charles Re Fllc, Dalid Bigmian, Da :id Schilling,<br />
Jared Coho, annd Richard Church<br />
EM.S hl(ation mriodels arc tlae Iorriiilald to address s5pc(ilc probllris<br />
of cmergercy mnedical services systemrvs; (ontecxt-free lonation niodels arc liaose<br />
developed *wilhout referencec o partirtular applications. The literature onx<br />
dI,cee t,'o iypcs, of pullic Iacility Iioc;tinu mrindeli is revise'cli. and Ic devel.<br />
opmnent of the maximnal .overiíng¡ nio(lel [rons several cma lier context-free<br />
models is described. witis cmphasis on poblen statcments anid articulatious<br />
ol service objectives. An applicationl of tlhe naitnial coverUsg mnodel lo fire<br />
truck location points up the ability of tlis rnodcl to handc nmultiple objerc<br />
tises: its ability to tomlpare alhicia solutions gives it great utiility for<br />
i>lanini>; and cvashllting EiMS systcus o(l a wide raut;c of comiplexity. I'o<br />
tential applications of the maximal covering inodel arc discussed rcgarding<br />
EtlS problenms involving multiplc timic satandards and service objectives,<br />
location of special equipment, aid siting oI fixed facilities.<br />
'i lda(cment of facilities un a nciwork to rcspond to demands<br />
or tu alract consumers has blccome a subjcc lfor both study and<br />
teaching. The cxtensive bibliography by Lea [I] indicates how thc<br />
literaturc in this arca has burgconed in recent ycars. IThe literaturc<br />
includes investigations of the location of both public and private<br />
fa;...ies; much of the literature concerning both the public and private<br />
sectors throughl about 1970 was brought together in an articlc<br />
by ReVelle. Marks. and Liebman [2]. Private sector facilities arc<br />
often located to fulfill precisely stated objectives. suclh as minimnum<br />
cost or maximum profit. in conitast, ithe goals and objectives of public<br />
facility location are more difficult to capture and translate into<br />
quantifiable teras.<br />
The gradually evolving interpretation ol tlhe goal of maximum<br />
public welfare has led to a number of possible problemni statements in<br />
thc sphre of public facility location. Each of these diffcerent statemelits<br />
has the potential lo fit tle perccptions of some decision niaker.<br />
RKcogniring the vatiklity of nmany ot>jectives has bro¡xght us to wha;t<br />
Addres communicatiolis and iXqlu.sss for ip:lilu t(o Charlic ReVrlle. Pro.<br />
ipam in Syuemu Analyais a*nd Ecoomnis íor Publir Deisieons Makisg. Johss Hopkins<br />
University. Bahimore. MD 21218.<br />
David Bigman is an «'onomlr with thre Iniernational Monetarn Fun(I; Dasid<br />
kShiUing ia asistant profesuo at the Centcr tor Technulory and Adrainistration. SUMMER<br />
American, Univel>ity; lad Coalol is ,u ite prnlcaor in tIre loIhns Ilopkins Pro 1977<br />
gram in Syerms Analyris and Eonounics lor Public )elision Making: and Richard<br />
Churth i aistiíant profesor of
- 296 -<br />
REVEI.LE we believe to be the most uselul oí probleni stal;tmcnts for the pub:<br />
E:' AL. lic f.cility prohlem. It i¡ a statementc thal adtnis tic multiplicity oí<br />
locational objcctives and sccks those spatial pattirns that are superior<br />
under a number of ,hese objectives.<br />
'IThe purpose ol tiis article is to rcview thic location analysis literaturc<br />
of the last fecw ycars that deals with public eiergency lfacilities.<br />
Sorne of thisi literature represents studies directed toward specific<br />
problems ol emcrgcncy medical services (EMS) systeras. primarily<br />
location of ambulance dispatching points. Much of the lictrature.<br />
lhowvecr. reports contex-free mode dels developed o atidlrcss location<br />
probleiis imn general; these mnodels are not ticd to specilic applications.<br />
Nevertheless, cach oí IIhe context-free miodels we shall discuss has<br />
been applied in planning some forni of cmergency facilities. Wc<br />
sh;lil trace iie develoipmient of thc coilteI .frcc moidcis inod .discuss<br />
Iheir pieniaiil for furthier application iii emergency medical recovery<br />
systciis. T'Ihere is an ad:d-tionial body oí location literature thait trals<br />
locations on a plane, using ithe Euclidean metric; these works will not<br />
he rcvicwed liere becalisc we feel that thc aippro:cil lacks rcalism fro<br />
thie ypes of problems we wish o ; !dress.<br />
Location-Allocation Models for EMS Systems<br />
Ihe location-oriented literaturc Lth:t has ben developed in the<br />
specific context of planmling emergency sysiems may e dlivided into<br />
twu catcgories: thc first is coniLrtic n mainily with locationial and<br />
sr!aial rcnsidcralions and occasionally inclides notions of randonm<br />
.v,::? thiat are explored in an iecrative fa.slion throtugil simulation or<br />
IqueCeing. Severnii o thlese works draw on the context-free location<br />
literature. Thie secontd ci.tegory addresses thli event-service sequence,<br />
with eniphasis on the random components o tlhe events. Location<br />
anl. ', when it appears. is generally an ad Ihoc rather<br />
integral leature oí thlese investigations.<br />
ithan an<br />
Spatial Analysia Applied to EIMS<br />
Focusing on the average response timne. Vol¿ 3] applied a "steep.<br />
est descent" procedure to eici,iiine locatiuois of ambulances. The<br />
procedure, unlortunately, is subject to entrapinmet at local optinia.<br />
Alhhouglt best soliations are possible, there is no way shiort of enu.<br />
meration to verify whetiher a solution is inferior to the true optimum.<br />
The model's suitability for planning ptirposes is hindered by its requiremnents<br />
for data and computer time. Its complex structure makes<br />
it very dillfcult to introduce other considerations and additional objectives.<br />
The assumptiíon that emcrgenicy calls arrive as a Bernoulli<br />
procesU (i. , with stationary independelnt inrcreients) may be unrealistic<br />
in certain contexts. Volz added other assumptions thiat reduce<br />
thie mathematical coniplexihy but impair themoldel's useuilness. NeviL^.LTkH<br />
ertheles, thlis model was the fi st to trcal the interactiiou I>ctwcen<br />
SlRVICUS<br />
RESEARCH lo
- 292 -<br />
from tile demandl sites. He used both a simulation an< a ql
- 293<br />
R£VELLE is apparent in light of accusations about wastelul diuplications and<br />
eT AL underutilization of critical care units. Willemain's model illustrates<br />
the inierrelationships among'important planning variables bl>t does<br />
not lend itself direcily to empirical use.<br />
Event-Service Analyses<br />
A multiple-server queiucing model was uscd by licl¡ and Allen<br />
(l]j to deternmine tie riiniber of amblulances neicdcd to :achievc specified<br />
response times. They assumed that tihe temporal distribution ol<br />
calls .ould be describcld by, and meet tihe assumnptions of, a Poisson<br />
distribution; tihat is, that each event occurs independently of tihe<br />
preceding one. Unfortunately. tihe extension to multiple servers distributed<br />
across the network posed severe complications beyondl tihe<br />
mnathematicil coniplexities because of the need to define rules of<br />
prccedence and responsibilitics for each arca.<br />
Savas [121 analyzed ehe cost.cffectiveness ol pioposedl challges in<br />
New York's ambulaince service with a descriptivc sinimulation model.<br />
'I'he simulation was of a standard sort. developed witli I¡BM; ahlerna<br />
tive locations were investigated ,I trial. 'ie costcffectiveness was<br />
dlisplayedl as a benefit/cost ratio o. zminlites saved to additioínal (ol.<br />
lars expended per mionlil. 'Th'lis was a stlamigitlorward bti pioicering<br />
eclort to use quantitative methods on anr emcrgency service system.<br />
NMeasuring benefit in lives saved, Smith [13] developed a benefit/<br />
ost analysis ol a coronary emergency rescte service. He used botit a<br />
quetieing atI a simulation model, with no appreciable difference in<br />
·. h. C.aly aggregatc data werc av;ailable. whichí reduced t¡he reli.<br />
ability o tlihe an.;lysis.<br />
Stevenson [j1 used queucing theory to estimate dispatch delay in<br />
ambulance service operations. For a given number of ambulances,<br />
he provided order.of[magnitude estimates of the minimum expected<br />
response time, using aggregate data antl a simple queueing model.<br />
The data reflected general regional characteristics such as average<br />
speed. area, and total number of calls. The results were expected to<br />
help the decision maker determine equipment allocation levels. Ex.<br />
plicit locational considerations wvould probably have provided more<br />
uselul result.<br />
Chailken and l.arson (15] explored the characteristics of urban<br />
emergency scrvices and reviewed tlie operational problemns of these<br />
systems. Their concern was with vehitle deployment and application<br />
ol queueing (chiefly) and simulation approaches to these problems.<br />
They considered allocation policies relatecd to the number of units,<br />
location and relocation of units,. response areas, and patrol patterns.<br />
Acton [16) studied tihe cost-effectiveness of five alternative heart<br />
attack programa. Many ol the uncertain parameters in the analysis<br />
were bhaed un estimates hy a panel of experts. He usedl a Mlonte Carlo<br />
IEIALTH simulation to ciaTulate expccted lives saved and assoiated costs of<br />
RESEARCH cach program. The benefits duc , , savel lives were ectimated by<br />
livelihood saved and by willingness-o.tpay measures; the latter were<br />
obtained from questionnaires and require further study to gauge
- 294 -<br />
thcir validity. Cretin [!7] analyzcd ilhe process of dcathi followinii FACILTY<br />
nmyocardial infarction and developed a model of risk of death fronm LOCATION<br />
inriarction. ¡ler model combined features of both the disease process<br />
a;i.d tie msiedical iolpunse and was used to evaluate policy alternatives.<br />
Thec disease was nimodeled as a discrete Mlarkov process, withi transition<br />
probabilities and other paranimeer: obtaincd froin statistical regression.<br />
I'lhi is an interesting approach, whlici coulhl form 3n integral<br />
l:art ou broa;der rm ,dels.<br />
l1cvcs,,olS aind Willeniain [18,19] vicwed thie scrccnitig process as<br />
a triage system. in which calis were alloated to prinmary service if<br />
Ihey wiece ciecrgcncies and to secondary service if they werc not.<br />
Cadlls wicrle aso routed to tile ecoundary service il all priuniary service<br />
vehicilhs were buisy. lhe analysis consisted of comibining assiarimed decision<br />
and evesst probabilities. Although the approaci was straightl.<br />
forward. tile assurmed prohabilities were not justified by the autihors.<br />
Ti'ese models and ,,ncceptualizations representl tle state of the<br />
;ar as relletied by tihe EMS-oriented literature iup to about oIIc ycar<br />
ago. 1i is clear tisat there is great potential íor lurther application of<br />
locatiota niodels to ENIS problems. We believe such applications will<br />
draw heavily on the cointext.free location litera;iav specifically on<br />
tihe Imaxinmal covering model and its refisenicenis, whllli atre distIissce<br />
below.<br />
Context-free Location Analysis<br />
An interlocking set ol tihree network loiation mnodels will be<br />
described here. A!' :aideb hta;.. have been applied. at least conceptually,<br />
lo emergency seivices. Tite third model (tile ttmaxiinal covering<br />
model), whose lurdier developmient and refincient we sihall discusIs<br />
has recently bcen applied to the location o[ fire stationis and<br />
equipment in Baltimore,'MD. I'lis i¡, to our knowlelge. tíhe first<br />
applications of this model to such a seiting, although it is chiaracterized<br />
by the moht versatile and adaptable objective of all thrce niodels.<br />
The p¡Median Problem<br />
The location model that underlies, tieoretic!"l)y and historically,<br />
the others we sliall discuss is the p-median problemn. whicil was pro-<br />
Iseld by Hakimi [20,21] in the context of locating switchiing centers<br />
in a communications network. It was recognized. lhowever, that the<br />
probiem statement could be extended to many otiher fiames of reference.<br />
We will state it in the setting in which people come to facilities<br />
lor service, but it can easily be turned around to pertlin to the situation<br />
of serven going from facilities to points of demand.<br />
Locate p faciliies on a network ol denreds so tha tihe average travel<br />
lime of all uen is a minimnum. Since fhe Ifailities ate not dstiinguishetl<br />
Lt sire or specialiaiion. it is asumed tihat every user will travel lo hisa<br />
uearest facility. ,tJ MM ER<br />
Numerous researchers iave propxned sulution , .lihods tor thc<br />
p-median prublenm. and solution procedcsílt' are imporirant: a well-
- 295 -<br />
REVEt.EI.<br />
ET AL.<br />
poSJcd probleni stalticlcit withiout at adel a icatc solitioún |proedluic is<br />
of litle use. (Necveitilclss, olr primary concerl ha;is bcen withl prob-<br />
¡lem statementes. Capturin§g tic Io
- 296 -<br />
The Location Set Covering Model FACILITY<br />
A possiblc otitcome oí gradually tiilictiilng ihe miaxini¡ill tithme ! .)CTION<br />
constriintis is tit;li, at some point. tile p Itailities will hecome insufficient<br />
in nuirilbe lo t oer r all points of- dcialudl withiiil tlhc timec (onstraint.<br />
'I'he logical questiou t lh:t follows is, given tile time standlaríJd,<br />
wliat is tihe leais niumnber of facilities required? This question lcd to<br />
ite aot"".uIl;tisim<br />
and solution of thle loatiorn set covelilg probllnim by<br />
1'l'cls ct ¡,1 . 1:121. A stateimelt o1 tev plr)blcm is:<br />
Fiidl tihe iniaiiurnuin t¡iiiinLber of fatliieis ¡ aiad lihcir lou.lio.nas suct la :<br />
eJt I i. i lt ul dIci¡i1anld Ia;is 'a .ciliti) witilsis / tsllC u Isits.<br />
iterestiniigly. several specialistsL ins ciiie:rtiiy hicailil services have<br />
also posed this prob¡em, aliloghtil tlhey were unaw:;rc of ihe tractablle<br />
niathiematical strtucture uitndcrlyiuig it. liitmley [34] ga;vec i(t lolow.<br />
i"g verb.,Il It'illltCW)a<br />
' :<br />
Hlow nmasiy amlbulaictes? Arc li'tre riotiligh? 'l;lii is Jal .ICeCil ¡ehI: zC.<br />
ispons¢ timie? Usually iti a inctiopolilan arel. i¡ is 15 nmiúitsl .... II<br />
a 15 misnute responxs tinei il deiimallded. how mi;otv a:inmulances are rc.<br />
quirrd; wlrrc muull rley bc Iosi(ioiuilt ¡1 ptu iu ;,;.l( alsla Ct<br />
thal tihis criterion is nicie<br />
The saiime undamental questionis were asked by (:assid)y and Wilson<br />
in thlicis stmldy of thie l.oinlot Anmbilalile Se:vitc [3.iJ:<br />
llow maity velCiclc; 1.aulId .It Seivi£c hlavc asid luow siOUhild tIíh I.ll<br />
llcet be divid; *..'Cca .irceclicr auibula.igcs amad ithe vaJ¡iou s¡izs of<br />
sittiitig
- 297 -<br />
RM.VELLE<br />
EL AL.<br />
of facilities and thieir locations. A facility sitc tilat is eligible to cover<br />
a number of denlan¡d poinis is generally a miore ellicieni choite tIhan<br />
a site with only a Iew appearanices in tile nmany denianid sets.<br />
Wlien tile location set coverinig problemn was first stated anid<br />
solved. its precision ol problemn statenent. its strong relation to stated<br />
necls. and its straighlitforward solutíion metilod quiickly established it<br />
as a widely recognizc( nimodel for thei location of facilities. Thle suc.<br />
ccsslul ellorts of Public 'i'ccliology. Ial'. ini promintig thiis model floi<br />
locatitng fire stations lostered this recognition. 'I'lThe model has been<br />
rcquested for ause iti njearly 100 cities.<br />
The localioJt set covering niodel as tile first to use sl e ,nl:xiiiiii<br />
uiadi;;nce (uo tiime) ;is a deter-iiiiii;:l ol tic spati;il cotiligulatioit<br />
of facilities. As such, it was tile first to neet thie need for distante or<br />
tinie stantdal;r thal t liad beet stateid iitd he ic clirs ;saiiih!iii·c f alid tr;ivcl tlie lii .a git'si ssiiiiitle /, pI 'i f;il¡it. líe lh.a.<br />
IILALt I 11 tion Ket covertig niollvl igt:,res pIo¡ lationí, ;iiI ltil tile tI litliillííí<br />
SERVICl" tiunitber ouf Ifilities ietieledl so c 'rs' .1 set uo tlel. ml.l i,luiit>s withiiil ;1<br />
iaslputle-tiinte stlandlarl. TI'hc .Ixialt.iil overitg mitlutc 1 .ihil.iit 1the<br />
ilsipurttilie uf IxJuiiatiul n stul drel.,il .í CSleiOt'.SiíS tili' .t.tl' 1: ti(
- 298 -<br />
Fig. 1. Maximal covering model results: Percentage of<br />
population covered within 2.0 time units by various numb .rJ<br />
of optinmally placed facilities. Point B is a solution tou<br />
the location set covering problem.<br />
c<br />
o<br />
100<br />
o<br />
v .<br />
oa.<br />
o<br />
e<br />
- 50<br />
o<br />
o<br />
c<br />
e<br />
. _<br />
00 ,E<br />
o<br />
o<br />
4 8<br />
Number o1 flciliHties ued<br />
Ia¡ ilitie are to be placed so a> to cover as much of the pIoptulatiolu (or<br />
as tsallny dmi;atld Ipints) as Possible. Wilen p, the liuint un I:t ilities,<br />
is niacreilsd to tihe !)oint iiat 1(10 percent of hi1 tdel:iítantl is covered<br />
by tihe a axiiiial bovering iiodel, its va;luei is sle aic a- tilte unii.i<br />
iitiii numinbCI indicated by the Ioc:alion set (overilag nmodel; tile latility<br />
placemenits indicated by tite two incdci, el howevari.<br />
sarily be tihe same.<br />
will oltu Icls.<br />
TIlia. maximal covering model fill ata ilii m,,.tant need in locatioii<br />
analyis. It
REVELLE<br />
ET AL.<br />
HALTOI<br />
SERVICUS<br />
RESEARCH<br />
- 299 -<br />
Fig. 2. A solution to the locatino set covering<br />
problem. Facilitiea (circled dots) are placed so that<br />
all demand points and 100 percent of the<br />
populatiun are witiin 15-unit limits (jolid lines\<br />
from some facility. Dashed linres are 10-unit limits<br />
from cach facility; they enclose only :31 ¡perccnt<br />
ol tihe populalion.<br />
placed facilities will cover 90 pcrcent ofl tle dcimamidi. elic (litcstioi<br />
is imrnediately apparent: are t!he four aduidiioinal la ilitics wortlh<br />
their cst. wben thiey cover only the last 10 pertent of the denm;md?<br />
The location et covering muodcl would Iave yielded only the inforination<br />
underlying point 13 of thc grapih.<br />
Solutions available from thie locatíio set coceting miodel are<br />
rigid. in that all points must be coveedsl; ini additioun, the sohltions<br />
are not "tight." Extensive computatioinal experience indicates tihat<br />
the mininimuni nunmber ol lacilities to provitde :over mu;y br ;a¡r;aiged<br />
in many ways without significaultly violatinig the futd.ilidimt:il uovirage<br />
standard. Applictaion of the mi.íxiíiil. *osc iti¡g niKlCl *a0t oftCi<br />
improve on solutions oblainable Irom thle lc;ilio e' t i>is¡ls. liiws ii ¡: g I. I .íi¡
- 300 -<br />
Fig. 3. A maximal cuvering solution to the location<br />
problem of Fig. 2. Facilities (circled dots) are placed<br />
lo that all demand points aml 100 percent ol<br />
the population are withian 1i-unít limits (solid lines)<br />
from some facility. Dashed linc, are 10.unit limits<br />
from each facility; they enciose 55 percent<br />
ol tihe population.<br />
- -<br />
is one of tlhe many possiblc solutions to the prolblem of minirnizing<br />
the number of facilities (five) needed to cover all points within 15<br />
timenc (ur distanice) units. The tdlusters surrounted by solid lines in.<br />
clude points within 15 units of thec Iacility to whicl tibat cluster of<br />
uiints is assignietd. lhiec dashed ¡lisn suiround puints tat aerc withini<br />
10 units of eacai cluster's facility; these points represrint oily 31 pertent<br />
oL the area's populatiosi. The reinai:iring G9 percent o thic populatium.<br />
althoughl it falsa withioi the 15-unit limit. is mirce than 10<br />
units away fromi alny lacility.<br />
Figure 3 representa anothier solution to tlie probtlen. obtained<br />
with the maximal covcring model. Th*is solution was Loomputed with 1977<br />
¡he ,ame number ol facilities. and all pointis stil Iie within 15 units<br />
ol thleir lusest latility. T'le omullutiaioiil. however. sought to mllaxi-<br />
FACIIITY<br />
L)CATION
REVELLE<br />
ET Al..<br />
- 301 -<br />
Fig. 4. Another maximal covering approach to the<br />
location problem of Fig. 2, with 15-minute constraint<br />
relaxed. Facilities (circled dots) are placed so that<br />
95 percent of the population is within 10-unit limit<br />
(dashed lines) from tome facility; 98 percent is<br />
atill within 15-unit limits (solid lines).<br />
mize the population within 10 units, given tice countra;int of keeping<br />
the entire population within 15 unitu. In the new configuration 55<br />
percent of the population is within 10 uniht of a facility. Although<br />
the location set model nuight have foutd thiis solution by chance, tihe<br />
probability of its doing so is low; in general. onily explicit optitnization<br />
using the maximal tovering model cain hc expected to yield sudc<br />
solutions.<br />
If the rigid constraint of complete cever-gec witil¡n as: ouiter liiit<br />
is reLaxed, alternative configuratiois witl puosilly molu e sic'l'l charirIAMit<br />
acieristiis may be derived. Figure 4 depicts a solutioii ohtaiiicd witi<br />
SRaLaaiUR tbhe standard of 15 units discarded. Fiv'. facilities can cover '.Y5 percent<br />
ol the population witlin 10 units wilce leavislg ulry '2 l.'cint<br />
o the popuilation otusieir a 15.unit p
- 302<br />
Multi-objccuve Maximal Covering and Fire Station Locatimo FACILITY<br />
Iri thc past year we have bcen assisting the fire department of the LOCATION<br />
city of Baltimore in planning its future system configuration. Thc<br />
National Board of Fire Underwiiters (now tihe Insurance Services Organization)<br />
has stated guidelines lor fire protection (391 that arc similar<br />
to those given by the EMIS regulations except that they are given<br />
in teirms of distance. The fire siandards are absoluitc: they do not<br />
include thie 95-percent specification thlat gives the EMS standards<br />
their realistic flcxibility. In practicc, however, it is accepted that<br />
absolute attainment of the standards is not within reach; thus the<br />
maximal covering model is appropriate and useful in this setting.<br />
Althiough thc fire standards are expressed for coverage of property.<br />
coverage of the population is anothler obvious objectivc. The<br />
fire hazard to population and thie fire hazard to property. determined<br />
as the product of population (ur property valuc) anid fie fre frtlcecy<br />
for subarcas of the city, constitutic still other mncasures againllst whi:<br />
to gauge coverage. Coverage ol fires, as reflected in fire frcquncicy, is<br />
also an important ofjective. These issues wcre worked out in consultation<br />
with the firc
- 303 -<br />
REVet.<br />
¡T AL<br />
Act of 1973. The menaning of an "adequlate nul>cier of emergency<br />
vehicles, called for in the legislatioan. is interpreted in the regulations<br />
as a number suifficient tlhat 95 percent of relquests for assistance can be<br />
met within 30 minutes in rural areas and 10 minutcr. in urban areas.<br />
To the location analyst. tihe framers of the regulations lor emergency<br />
services appear ao he among the most articiulate of decision makers.<br />
for their specificatiolis of elfectiveness mnicsures are cear, concise<br />
mathematical entities. Tihe analyst is seldom fortunate enough to<br />
encounter such precise problem statemcnts.<br />
The coincidence of viewpoints of tie frainers of t¡he rcgulations<br />
arid the autihors of the naxinial covcring model suggests, correctly.<br />
that this model was structured to meet real needs. In fact, the origin<br />
of thle model lay in a 1970 report of the Carnegie Comnission on<br />
Higher Education (42]. That report called for establishment ol 55<br />
t<br />
lieaith i are teiters acroís the natiol, loatced iii stlch a way that 95<br />
percent of the populatio.! was within :an hoiir', drive of a faciliy.<br />
IlThe numinbers aside. this concise stat,:imtciit sparked the lcvelopinicivt<br />
of the maximal covering problem by Chur(hl and ReVelle [41] out ol<br />
lthe location set cove'ring problem.<br />
The maximal covering inoxlel ullers adtlitiona.sl informination beyond<br />
that requested by the EMS regulations. As discussed previously<br />
in connection wiíth Fig. 1 (jp. 137), tihe maximal covcring model can<br />
indicate noi only the n numbe r and locations of vchicles requuired for<br />
95 percent of responses to o(xcur within 3S minites. but also the nunmhkr<br />
arul !ocatiois needed for any coverag;e level one wislies. allowing<br />
..
- 304 -<br />
population center; the use of secondary outer standards could ame. FACILTY<br />
liorate the situation o thiose who represent the 5 percent of demand LOCATION<br />
that is ex mpted Iromn tlie regulation standard.<br />
Still other uses u thie maximal coverirng model are possible: alter<br />
maximizing coverage within a stated time, one may seek tiue solution<br />
tihat minimizes the average service time for tiose outside the stand;trd.<br />
Tite economic and geograpliic options available to planning<br />
regiouis difler cnoughl that each region miglit benefit. both in service<br />
and in cost. from "fine-tuning" its EMS plan by examining many<br />
such secondary solutions withisn the regulation standards.<br />
Sonme work has already beien done oin ;aplying time other two<br />
toutexxit.ee models, tihe p-median andl tihe location set covering models.<br />
to emnergenry ambulance services. The work of ReVelle, Tore.<br />
gas, and Falkson [38) cited carlier extends the location set covering<br />
model t to twn nore detai:ld tspects o! tie EMIS locatiosn problemn.<br />
()nc ol limes, .Isp:Cts concerns travel stieC oli tihe link froni demant d<br />
¡point to care facility alter time patient is pickcd t up whlidi needs to bc<br />
considered in determining ambulance locations. The other aspect is<br />
that demands in the real world tend to occur along continuouis roads<br />
rather tihan at discrete o Berins. erln. l. 'elle. anit Elzinga [43) used<br />
time p.mediant framework to investigate tie riisinimum average time<br />
when the travel from demand to point of care is included. We<br />
have not yet applied the maximal covering nmodel to these more detailed<br />
expressions ol the problem, but it will be usefucl to discuss here<br />
omrne possibilities inherent in sulch an application. These possibili.<br />
ties si: :.d ir,- of interest to EMS policy makers, since they allow the<br />
evalative standarda diseussed in the regulations to be extended to<br />
include the link from demand point to point of care.<br />
When an ambulance arrives at the scene o a call. certain limited<br />
care may be given the patient, depending on time training and equipment<br />
of the arriving personnel. The time standards for response to<br />
calls apparently apply only to the arrival of the ambulance at the<br />
scene. Thle purpose of tire ambulance is twofold. however. and the<br />
second function is transporting the patient to a staffed antd equipped<br />
emergency care center.<br />
Without meaning to suBgest dilterent values lor the time standards.<br />
it would seem useful to apply a time standard to the entire<br />
time between dispatch of the vehicle and the patient's arrival at the<br />
emergency care facility. 11 thie 30.minute response standard were extended<br />
to cover both functions. more vehicles and locations would<br />
be required to achieve the stated coverage. Two standards might be<br />
formulated. one for time time from ambulance dispatch to the emergency<br />
scene, tihe other for the entire time from dispatch to the appropriate<br />
site of care. Time addition of this new standard provides<br />
another yardstick widi whicl lto nmeasure the effectivenes of an emergency<br />
recovery system. Modeling with this added standard does noU<br />
seem to present any insurmountable challenge. UMNER<br />
Still another standard could be applit 1 lor the time from dernand<br />
cene to hospital. Application of such a stalidard, however, is not
- 305 -<br />
REVELLE possible within ilhe location concepts discussed tliur, lar. whici focus<br />
ET Al.. on tile dispatchl location of emergency vehicles. Achievement of a<br />
standard lor tile demandl-point.to-hospital Ieg of the transportation<br />
triangle (depot lo demand to hospital to depot) can ciily be influenced<br />
by the locations of emerg;ency care hospitals.<br />
The locations of aiuch hospitais in turn affect the vehicle loca.<br />
tions needed to achieve standards on the entire depot.to-point.ol-care<br />
time. The twin problems are interlocking and complex, but potentially<br />
solvable. Together the two problems of ambulance location<br />
and location of emergency care facilities comprise almost all of tihe<br />
transport segment of emergency care. Seen as two interlocking problenms.<br />
they give rise io a more basic question:<br />
With limited resources lor purchase and opcration of vehicles and for<br />
establishment and opcratio.m of emergency care facilities. dctennine the<br />
nunmber and localionís of boill ¡Ihat will maximize the proportion of resloScs<br />
occurring withi.i the lime sandard.<br />
A complementarity of achievement exists between emergency vehirles<br />
and emergcncy care facilities. An additional emcrgency care<br />
facility miglht oblvi;:te the need for I ,r (to choose a number) emergenty<br />
vehi(lies by dliiiiisling thc total time from dispatch to final<br />
care site. The maximal covering model will permit these trade-offs<br />
to be examined. The relative costs of mobile and fixed facilities<br />
would indicate whiclyhuoicses were appropriate and open the possi.<br />
bility nl cost.eflcctilness comparisons that could Icad to EMS syst(..<br />
,. wuld be'1.both functionally and economically optimal.<br />
Summary and Conclusions<br />
We have discused the remarkable hainiony between the structure<br />
of the maximal covering model and ihe goals of policy nmakera.<br />
The ability of the model to deal with multiple objectives and to opti.<br />
mally asaign special equipment to optimally-located depoits, as in our<br />
fire department study, indicates the model' general utility in a wide<br />
range of location problema. It should be particularly useful in plan.<br />
ning and evaluating emergency nicdical systems.<br />
In location research (perhaps in other types of resc'rchl as well) a<br />
aymbiosis exists between the setting of a particular application asid<br />
the development of models. Lcation models aid in conceptualizing<br />
a problem in a particular setting and the special characteristica of<br />
the setting feed back to enrich the location model. We expect such<br />
aymbiosis from the EMS setting. We believe that location analysis<br />
can make a significant contribution to the evaluative structure oí<br />
such services and that tlis setting will add new and important di.<br />
mensions to location ¡clcarch.<br />
l1tALTH.' REFERENCES<br />
silavíC I. Lea. A. An annouted bibliogiaphy olf , lei io.aUocaIoU I Wolking pH'ry. I>.<br />
lESAtmti of GCeogaphy, Uniacnisiy olf uunto. 1973.<br />
ReVelke. C. D. Marks, and J.C. l.iáeman. An analysti ol privale and publitc wc<br />
lor loation modrit. Mondge Sti 16:62 July 197'0.
- 306 -<br />
3. Voli. R.A. Optimum ambulance location in acmi-rural arcas. Trans, .Sri 5:198 FACILITY<br />
May 1971.<br />
4. Fitsuimmons. J. A methodology for emelgency ambulance deploy)rrtit. Manage<br />
Sei 19:627 Fcb. 1973.<br />
LOCATION<br />
5. lerlin, G. and J.C. Lltbiran. Matilrmnatical anal)yis of<br />
location. Socio.Economic Plann Sri 8:323 Dcc. 1914.<br />
tnc-lgciucy amnibula cc<br />
6. Stidl'lim. S.. C. Toregas. and G. Iisher. Operatiolial analy.si of dcmand-.es-poi.<br />
isvc a>stema. Department oí Envlmnrnmental Systemins Eumgincaing. Cnimell Uni-<br />
imbity. · Report to the New York Siate Scicnce amd T'ed.lillogy F'oundation.<br />
Jan. 1971.<br />
7. Stidham. S. Stochasiic dcsign modcls for location ant allocatiorn of public scrvice<br />
lacilities. Depanment of Environmental Systems Engineering. Cornell<br />
Univsenity. Reron co the New York State Science and Technology Foundation.<br />
May 1971.<br />
8.
- 307 -<br />
RLVELI.E 29- Khumawala. a. An cffricie algorithm tor h. 1973.<br />
30. Swoveland. C.. D. Uyeno. 1. Vertinsky. and R. Vickson. Anilmtlance locallon,:<br />
A probabilistic enunication apprlahla. Alanoge Sci 20:616 DI)c. 1973.<br />
31. Carbone. R. Public facilities location unelcr stochastic dcmand. INFORl 12:201<br />
Oa. 1974.<br />
32. Toregas, C., R. Swain. C. Re'.Vclb.. and I. Ihkm.nlnti. 'rhuc lkliiin tío a Lti( al Iti
.'17<br />
- 308 -<br />
INITER.'ACES Copyright (e 1979, The Institutc of Management Sciences<br />
Vol. 9. No. S. Novcmiber 1979 0o92-2102/79/090510003501.25<br />
THE LONG ISLAND BLOOD DISTRIBUTION SYSTEM<br />
AS A PROTOTYPE FOR REGIONAL BLOODMANAGEMENT<br />
Eric Brodheim<br />
Lindsley F. Kimball Research Institute, The New York Blood Center, New York, New York 10021<br />
and<br />
Gregory P. Prastacos<br />
Department of Decision Science, The Wharton School. University of Pennsylvania.<br />
Philadelphia, Pennsylvania 19104<br />
AISTRACT. Eacti year ovcr two million htospitalizcd Americaiis dci.n1tl<br />
pon Ilhc ttilm ely av;iilaililiiy ofl Ihle riglht yp.c of hinod i)rojucls . t 6.O(XH)<br />
ioslpitlal hlhto banks (HUUB's) in thie United States. If the right bIood products<br />
are not available al thc HBB whcn requircel. thcn medical coinplicalions<br />
or postponements of clectivc surgery can result which translates to extra<br />
days of hospitalization and expense. On the other hand, since most blood<br />
prodtlucls may only Ihe adllinislerLcd io)t ia pliCllh of tic saillc bild typlc withiln<br />
21 days of collectiot., overstocking at HBB's leads to low utilization. which<br />
increases costs and is wasteful of the scarce blood resource.<br />
The Long Island blood distribution system was set up as a prototype of a<br />
regional blood ccnter and thc hospital blood banks that it services collaborating<br />
lo preplan regional blood tlow. It maximizes blood availability and<br />
utilization accordling to a Prograinmcd Blood Distribution Systenm (PIDS)<br />
model and strategy that has been shown to be generally applicable. PBDS<br />
schedules blood deliveries according lo statistical estimates of the needs of<br />
each HBB and monitors actual requirements lo adjust deliverics whcn indicated<br />
by control chart techniques. In addition, it provides a daily forecasting<br />
of shorn-erm shortages and surpluses for the next several days that results in<br />
controlled movement of blood to and from adjoining regions. Finally, the<br />
system is able to adjust the regional strategy so that availability is reduced<br />
uniformly at all HBB's during periods of seasonal. regional shortages.<br />
PBDS has drastically improved utilization and availability of blood on<br />
Long Island: wastage has been reduced by 80%, and delivery costs by 64%.;<br />
This prototype is acting as a model for other regional blood centers in the<br />
United States and for other national blood services as a basis for planning<br />
and controlling blood flow in a geographic area. It usually replaces preexisting<br />
procedures where a regional blood center collects blood based upon<br />
gross estimates and reacts to requests for blood by individual HBB's on the<br />
basis of experience and on the currently prevailing inventory situation.<br />
Introduction<br />
The Operations Research Laboratory of the New York Blood Center, in collaboration<br />
with the Long Island Blood Services (LIBS) division oí the Greater New<br />
York Blood Program (GNYBP), has been studying the probleni of providing a high<br />
availability of perishable blood products at each of the hospitais in a region, while<br />
HEALTH CARE-BLOOD BANK<br />
INTERFACES November 1979<br />
Z.; ~~ ~~.<br />
; y.,,p `, ~~~~. , ¿;~~. 11- 1.
- 309 -<br />
assuring thal the maxinmum nuniber of these products are utilized during their 21-day<br />
lifetime. This problem requires thai the dual and seemingly conflicting concerns<br />
about availability and utilization be reconciled. It also rcquires a radical change in<br />
management decisicn concepts so that the regional blood center (RBC) that is responsible<br />
for collecting and distributing blood and the hospital blood banks (HBB's)<br />
that stock it for possible use recognize common objectives and collaborate in implementing<br />
a strategy that optimizes the regional utilization and availability of these<br />
scarce products.<br />
The first section of this paper describes the national problem. The Management<br />
Science techniques lthat were utilized to create a transferable mnodel for a distribution<br />
plan with near-optimial characteristics are dcscribed in the second section. This is<br />
followed by a description of the implementation of this model by the Programmed<br />
Blood Distribution System (PBDS) and of its testing al LIBS as a regional prototype<br />
for the Cvolutioni of a national blood distribution netwourk and operation. The managerial<br />
and economic impact and the implications and extensions of this prototype model<br />
are then discussed in the concluding sections.<br />
Background<br />
The national problem<br />
Mosl blood products in the United States are derived from whole hlood thlat is<br />
collected in units of one pint from volunteer donors by approximately 200 RBC's.<br />
After laboratory processing and testing, blood products derived from the whole blood<br />
are distributed to the HBB's in the region where they are stored to be available for<br />
transfusion when requested. This paper is restricted to whole blood and red blood<br />
cells (i.c.. whole blood from which plasma and other components have been separated),<br />
which together account for over 95% of all transfusions. Both have a lifetime<br />
of only 21 days during which they can be transfused to a patient of the same type and<br />
after which they have to be discarded.<br />
Historically, HBB's have maintained high inventories of most of ihe eight<br />
different types of each of these products in order to provide high availability to<br />
satisfy patient needs'and have accepted the low utilization resulting from spoilage.<br />
Consequently, the national utilization rate of whole blood and red blood cells prior to<br />
expiration was estimated to be only 80% in 1974. At that time, the federal government<br />
adopted a national blood policy that called for an all volunteer blood supply to<br />
be accessible to all segments of the public. The blood supply was to be efficiently<br />
administered through the formation of regional associations of blood service units in<br />
each of which a RBC and the HBB's that it serves would collaborate to achieve these<br />
objectives.<br />
The role of Management Science<br />
It had long been recognized that Management Science techniques were required<br />
to improve blood utilization and availability. Strategies with desirable characteristics<br />
were formulated for individual hospital blood banks and pragmatic regional approaches<br />
that improved performance in a certain region had been implemented and<br />
INTERFACES November 1979
- 310 -<br />
reponed. Thec Nutional Heart, Lung and Blood Institute Resources Panel in its 1973<br />
recommendations, which were a major factor in formulating the National Blood<br />
Policy [4], stated that:<br />
One of ihe strongect arguliculs I'ivoring tihe introduction ol s)'slcins management lo<br />
blood service is that it will result in improved service. in more economical utilization of ihe<br />
blood resources, and most important. in iniproved effectiveness and efficiency. For these<br />
reasons ii is recommended ihat emphiasis be placed on developing micasures of activity und<br />
relalting thcse io objectives. Only ii ihis wa;y will it bc Ipossiblc to oill;lio secire antl credillc<br />
cvaluatioin of the chaigcs lo ble mi'dc.<br />
This study addressed these issues by:<br />
(1) creating a model for relating measures of blood banking activity to<br />
availability and utilization;<br />
(2) developing a management tool called the Programmed Blood Distribution<br />
System (PBDS) to implement a regional blood distribution strategy that is based upon<br />
this model;<br />
(3) evalluating the effectiveness of PBDS in a prototype region (LIBS).<br />
Complexity of the problemn<br />
The complexity of the blood distribution problenm is primarily due lo the perish.able<br />
characteristics of blood, to the uncertainties involved in its availability to the<br />
RBC, and in the variable daily demand and usage for it at each of the HBB's. Thc<br />
situation is complicated by the large variation in the size of the HBB's supplied, the<br />
incidence of the different blood groups, and the rcquircments for wholc blood and red<br />
blood celis at individull hospitals.<br />
Since it is a national policy for blood to be derived from volunteer donors, its<br />
availability is uncertain and is a function of a number of factors thait canniot be<br />
controlled by the RBC. The demand and usage of blood at HBB's arc also unicerlain<br />
and vary from day to day and between hospital facilities. The HBB's within a region<br />
may range from those transfusing a few hundred units per year to those transfusing<br />
tens of thousands of units per year. The most frequently occurring blood type (0<br />
positive) occurs in approximately 39% of the population, while the least frequently<br />
occurring blood type (AB negative) occurs'in only about 0.5% of the population.<br />
While most medical authorities agree that at least 90% of all blood trans.fusions could<br />
be in the form of red blood cellis, sonme hospitals transfuse almost cntirely red blood<br />
cells while others transfuse entirely whole blood with the ratio of whole blood to red<br />
blood cells frequently changing with time as transfusion practices improve.<br />
Approach<br />
The transfusion services throughout the nation are characterized by diversity.<br />
Each RBC has independently evolved its own philosophies and tcchniques for blood<br />
distribution. Each region strives for "self-sufficiency" iii supplying the blood nceds<br />
of the hospitais in its region from donors who also reside in approximately the same<br />
area. Because of these factors, it is essential that any strategy devised be defensible<br />
from the point of view of both the RBC and caclh of the wide range of HiB13's that it<br />
serves. Furthermore, any strategy that involves interactions between RBC's niust<br />
provide for clearly defined benefits for all participants. In addition, it is desirable that<br />
INTERFACES November 1979
-311 -<br />
the implemented strategy he c hitaraileri/cd h ixo imauaqgeii ment cn tcepis: rotation o l<br />
blood producis between HBB¾.. aínd irc.ilhCeduLId deliveries to ¡he HBB's.<br />
Any strategy Iha¡t aill>oeaes hltoitl Iprnnd itct, tio he retained t until ransfused or<br />
outdated will result in low uili.zation. cspciiaill in the case of tiie small usage HBB's<br />
which, in aggregate. aecoun
0 6<br />
- 312 -<br />
FIGURE 1. Availability Rate Model.<br />
le · · · ·- · · A nvAiLABiiTY<br />
1<br />
> I IJl/ I I J<br />
I90<br />
>- 1MEAN DAILY DEMAND, D<br />
MEAN DA11Y DEMAINlD, D<br />
It was similarly established that the daily usage co'uld be modeled as an exponential-type<br />
distribution whose paraimeter is relcted to tie mician dily us;agec (U).<br />
The dcinUand-to-uslge ratio (D/U) was found 1o vary betwceni 1.5 and 4.0 Ior mllost<br />
HBB's with an averagc valuc of about 2.5 iii most regionsl' Thcse unalyses shliowed<br />
that the parameters for the models of demand and usage coi Id be readily estimated<br />
from records maintained by HBB's and ftirther tlihat aviabilily ratc eCoi(d bc reliahly<br />
estimated by thec mIodel.<br />
Utiliza Iion /1<br />
The utilization rate (i.e., fraction of the periodic supply'iwhich is transfused) al<br />
an HBB depencis on the size as well as the age mix of its blopd supplies. In order to<br />
derive a model for utilization rate, ihe following basic distribution strategy was<br />
developed, based on the premise that periodic shipments are rade to each HBB. At<br />
the begirining of every "period" the RBC ships a fixed number of fresh (1-2 days<br />
old) rotation units and a fixed number of older (6-9 days old) retention units to each<br />
HBB. The retention units are permanently retained by the HBB.until transfused or<br />
discarded at the end of their useful:ife. The rotation units that are in excess of u fixed<br />
"desired inventory level" at the nd of the period are'returied to the RBC for<br />
redistribution as retention units. Since the rotation units a're fno subject lo spoilage,<br />
the utilization rate is determined by the behavior of the retention inventory.**'<br />
The number of retention unitsin inventory at a HBB immediately after each<br />
delivery can be represented by a hfinite-state Markov chain, whose trUnsition probabilities<br />
are a function of the fixed periodic input (i.e., che fised retention shipments),<br />
and of the variable demandland usage. Under the Ussu.Imp-ion that Ihe oldest<br />
unit in inventory is transfused firc, the steady state solution of thc system can be<br />
computed and related to the utilization rate. This model was examined in [3], where<br />
**Ulilized Units = Total Supply - Units Spoilad.<br />
INTERFACES November 1979
- 313 -<br />
analytical approximalions were derived for Poisson usage, relating the number of<br />
retention units in each shipment to the resultant utilization rates with the desired<br />
inventory level as a parameter.<br />
This rclationship is illustrated for a fixed utilization rate of 98% by the family of<br />
broken lines in Figure 2 where the scheduling factor P is the fraction of mean daily<br />
usage that is replaced by retention shipments. As an example, if a HBB's mean daily<br />
usage for a given blood product is 1.5, thecn the HBB can achicve a utilization rate of<br />
98% by any of the lollowing combinations: desired inventory 1= 1 and P =0.89, or<br />
1=3 and P =0.82, or 1=5 and P =0.70.<br />
0.9<br />
a: 0 7<br />
FIGURE 2. Utilization Rale Model.<br />
/<br />
- / CALCULATED<br />
L0. / I ¡ 3 /OPTIMAL<br />
I 0.ó r I / ,--- I=S<br />
FEASIBLE<br />
.(/) Y I / SOLUTIONS<br />
: 1INVENTORY<br />
LEVEL<br />
0.5 I I I<br />
0.5 1.0 1.5 2.0 2.5<br />
MEAN DAILY USAGE, U<br />
It was shown thatthis stocking procedure maintains the mean inveqtory close to<br />
this desired inventory level most of the time. It was also shown that adding additional<br />
stages of returns and redistribution would make only slight improvements in the<br />
availability rate and utilization rate achieved. Since multiple redistributions introduce<br />
severe logistical problems and significant transportation costs, distribution<br />
strategies involving more than two stages of distribution were not investigated.<br />
Properties of desirable regional allocation strategies<br />
Having derived models enabling us to predict the availability and utilization<br />
rates of a HBB fc- any rotation/retention policy implemented by the RBC, the<br />
regional allocation problem was examined. It was assumed that some fixed penalty<br />
costs were associated with every nonavailable unit and every nonutilized unit, and<br />
the objective was to determine the distribution policy parameters so as to minimize<br />
the total expected regional cost.<br />
INTERFACES November 1979
First, the policy that minimizes the total expected one-period cost was derived<br />
[5]. It was shown that this policy involves the following operaiions:<br />
(I) first allocate all available retention units so as to equalize the utilization<br />
rates at all HBB's;<br />
(2) then allocate all available rotation units (which are not subject to spoilage)<br />
so as to equalize the availability rates at ai1 HBB's.<br />
It was shown thait this pucicy is independent of the unit penalty. costs, and that is<br />
maximizes both the availability and the utilization of blood in the region, simultaneously.<br />
That is, any deviation froni the policy that would reduce utilization would also<br />
result in reduced availability for the next period, and vicc versa. It was next shown<br />
[6] that this policy was not only myopically optimal but also approximately optimal<br />
in the long run. Further, in a large number of cases that were tested by computer, the<br />
utilization and availability rates computed froni the myopic results also corresponded<br />
to the absoluite optimal values comnputed.<br />
This result established the principle that a distribution policy should seek to<br />
equalizc utilization rates and availability rates. This is also a policy that has thc<br />
essential elerents of "fairness' in equally spr!ading the nonavailability and<br />
nonutilization risks among hospitais regardless of their relative size and is consequently<br />
a highly defensible policy.<br />
Finally, it was shown that the highest possiblc regionil availability and utilization<br />
rates are achieved whcin the desired inventory level for each blood type in each<br />
HBB is at the value that minimizes the total number of rotational units that are<br />
required to achieve these availability and utilization rates.<br />
It is a straightforward effort by computer to calculate the combination of inventory<br />
level and schcduling factor that requires the minimum number of rotational<br />
units. The minimum number of rotational units required to achieve a fixed utilization<br />
rate of 98% and an availability rate of 95% are indicated by the points connected by<br />
the straight line segments in Figure 2. Thc irregular behavior of this solution is due to<br />
the fact that inventory levels must be integer values and rounding occurs on very<br />
small absolute values. As an example, the minimum rotational shipments required to<br />
an HBB of mean usage of 1.5 units daily to obtain the target goals above occur when<br />
the desired inventory is 5 units, and the scheduling factor is set to 0.67. The trend<br />
line which is drawn in the heavy line in Figure 2 is meant to indicate simultaneously<br />
the optimal values in inventory level and scheduling factor for given values of mean<br />
usage.<br />
Adding operational constrainis<br />
The above distribution model of equalizing availability rates and utilization<br />
rates among the HBB's is illustrated by the two curved lines in Figure 3. The upper<br />
curved line shows the minimum total shipments required to achieve a fixed<br />
availability rate at a HBB of a given mean usage. The lower curved line shows the<br />
maximum retention shipments to achieve a fixed utilization rate. The area between<br />
the curves would have to be met by rotational shipments. As can be seen from the<br />
right end of the curves where the tails meet, this results in a situation where the larger<br />
usage HBB's receive almost all of their shipments in older retention units, while the<br />
smaller usage HBB's receive almost all of their shipments in fresh rotation units.<br />
UITERFACES November 1979<br />
- 314 -
- 315 -<br />
rcquired Ior shipping and oilher piurposes, is iiscd to creale data files. Fronim hese data<br />
files, and using lihe model described above, "policy selection tables" are generated.<br />
These tables indicate the minimum total fresh supply needed to be distributed on rotation<br />
in the region over a two-week period, in order io achieve certain *acceptable' values for<br />
availability and utilization. On the basis olf hese tables, of the amount and the stability of<br />
the collections, and of the reserve to be kept at the RBC, the attainable values are<br />
determined. and the "target" values are selected for these performance measures.<br />
'-TO INITIALIZE SYSTEM<br />
Q<br />
I:l¢itt:l-i 4. Pnogrnlíinicd B l oold Distribution Flowchart.<br />
CREATE DaT* FILES |<br />
_J~~~PREPA<br />
SELE(<br />
IN STEADY - STATE<br />
INTERFACES November 1979
- 316 -<br />
Once thc planning phase is completed, hospitais are assigned to delivery routes.<br />
These delivery routes are constrained lo provide for deliveries lo aill hospitals at a fixed<br />
time each delivery day. Delivery day intevals are cither one, two, or four days,<br />
dclpendiíng on ihe size of lhe hospital alid special requirements or strong preferences<br />
expressed. Froni these assigniments "regional distribution sumniaries" per delivcry day<br />
are prepare(l for eval:uation. Thlcsc ae revised as needed to equalize the amnount of blood<br />
distributed cach day as far as possible. Individual hospital "sumnmaries of delivery<br />
schcdules" anid of 'desired inventory levels" are then prepared and sent lo all HBB's.<br />
After discussions during which the above distribution schedules are confirmed or<br />
modified as required andtl extensive educational sessions with the HBB's' management<br />
and operational personnel take place, thle operation is ready to start. The final step is the<br />
preparation of packing documents which are prepared in the order in which deliveries are<br />
to be made.<br />
Once operational, da¡ I'files or dislribution schedules are modified by one of two<br />
meanis. As new hospitais are added, as hospitals are removed, as changes in usage occur,<br />
such as those from incrcased bed capacity, or as chlilages in us;age are deleccd by hle<br />
control procedutire, i¡e tl;al; I'iles ae muodilied. 'I'he olicy selectiomn tables are revised<br />
eacl tiIme tilere ale revisiois ii usage estimates. The revised tables are then nmanually<br />
evaluated lo determine if the changes are substantial enough to require a change in<br />
targets. A change in targets may also be required if a substantial increaise or decrease iii<br />
the blood supply is anticipated froni othler iniformation. If such changes are required, then<br />
the regional distribution forecasting procedure is performed again as described above.<br />
Scheduling deliíveries<br />
A major advaintage of PBDS, both to the RBC and to the HBB's, is the ability to<br />
preschedule most deliveries. Prior to PBDS being implemented, a number of delivery<br />
vehicles were dispatched as orders came in. For urgent orders, vehicles were dispatched<br />
immediately, while for more routine orders an attenipt wa.vs made to hold vehicles back<br />
until several deliveries in the samne geographical area could be combined. This procedure<br />
was expensive and, perhaps more importantly, resulted in situations where even urgent<br />
orders were delayed, since delivery vehicles were not always available.during peak<br />
delivery hours.<br />
With the PBDS inost deliveries are prescheduled, and take advantage of known<br />
traffic patterns in order to mininiize delivery time. An interactive, comiputer-aided<br />
procedure was dcvised which assigns HBB's to delivery routes so as to meet their time<br />
and frequency of delivery requirenients. The twelve delivery day planning cycle is split<br />
into three groups of four delivery days, after which the delivery cycle repeats. In each<br />
four-delivery-day cycle each HBB receives either one, two, or four deliveries. Thíc<br />
procedure tries lo satisfy the delivery requircmenis without leaving gaps in consecutive<br />
time siots, since an emnpty time sloi indicates idle time.<br />
An opportunity to test the flexibility of this delivery schene occurred recently when<br />
the LIBS Blood Center was mnoved from one location to ainoiher several muiles away. 11<br />
was found that the delivcry roules couid be adjusted rapidly and the required reassign.<br />
ment of the HBB's was determined conveniently.<br />
INTERFACES November 1979
- 317 -<br />
Controlling ¡he system<br />
The shortage deliveries and the rotational returns for cach Iospital arc nionitored in<br />
order to dltect chainges iii hospilal requircilecils. Evcy Iwo wccks thc "discrepaincy"<br />
hctween tIhe hospilal's cstinialtdt and expected usagc during these two wceks is computed.<br />
This discrcpancy is added to the cuniulative discrepancy frorn prior weeks to form<br />
an updated cumulative discrepancy. which, togctiher with thic nutiiber ol wccks included<br />
in it. ald ihe vyaluc ol thic lhospitall's expected usage. are used to compute the "normalized<br />
cumulative discrepancy" of this week. This last value is compared with a statistically<br />
establishcd "limit;" if it excecds the lirnit, it is concluded that a shift in usagc level has<br />
occurred. New usage cstimaUes arc conmputcd. and new distribution schedules are prepared.<br />
Otlherwise, no action is takcn.<br />
Since the mix of the eight blood types is a function of the ethnic mix of the<br />
population, which is in a state of transition for some of the hospitais tested, the above<br />
control procedure was established for cach of the blood types as wcll as for all types of<br />
whole hlood and all types of red blood cells. Adjustmenis were made either by blood type<br />
or for all blood types. It was found that this had the unfortunatc characteristic that if<br />
overall usage was increasing or decrcaising, individual blood types tended to go out of<br />
control in consecutive evaluaítioni cycles belore the total usage chart went out of control.<br />
liis causcd an excessive number of distribution changes. For this reason, the concept of<br />
"waming limits" and "action limits' was set up. A changc is only milde il onc of the<br />
blood types exceeded Ihe action limnits. However, at that time if any other blood type also<br />
excecded tlhe warning limits, then that distribution would also be changed at the same<br />
time.<br />
Daily inve'ntory ailjustment<br />
The resulting regional blood flow is illustrated in Figure 5. In this figure the<br />
aging of the RBC inventory is indicated down the center of the figure with the<br />
scheduled movement of blood to HBB's indicated to the left of the figure and the<br />
nonscheduled movenment to the right. The long-dated, stock-dated, and short-dated<br />
RBC inventories refer to blood units that are suitable respectively for rotation shipments,<br />
for retention shipments, and solely for supplemental shipments - which are<br />
filled by the oldest available units. The arrows indicate the blood flow that is normalized<br />
to 1,000 units collected.<br />
On the basis of this anticipated regional blood flow, the RBC's inventory is<br />
evaluated and adjusted daily. Stock-dated inventory balancing is performed late each<br />
afternoon after all rotational returns have been received. It involves the part of the<br />
flow circled towards the bottom of Figure 5. The available stock-dated inventory is<br />
compared to the retention shipments that are scheduled, the anticipated supplemental<br />
shipments plus a small reserve for unusual circumstances which is shown as becoming<br />
short-dated inventory. When the inventory for any product exceeds these requirements,<br />
the excess units are designated as surplus, and transshipped to the New<br />
York Blood Services (NYBS) division of GNYBP. When stock-dated inventory is<br />
tThe usage is determined by combining the known weekly scheduled distributions with the recorded<br />
supplemental deliveries and rolational relums to form an estimate of actual usage.<br />
INTERFACES Noveniber 1979
- 318 -<br />
I'Fu Itii 5. Regional B3lood Flow Baliacing.<br />
SCHEDULED DISTRIBUTION RBC NON-SCHEDULED DISTRIBUTION<br />
TO HBs i TO HBBs<br />
I NVENTORY \Ni /<br />
STOCK- DATED_ ~ INVENTORY<br />
STxo OO LONG-DATED<br />
V \ / ~~ I~NVENTORY<br />
LONG DATED ALANCING<br />
RBC<br />
RBC<br />
O T DAT 0ED<br />
OUTDATED<br />
DESIGN\TED<br />
below requirements then either surplus long-dated units (if available) will be retaíined,<br />
or the shortage will be made up from the other divisions of GNYBP if<br />
p~ssihle.<br />
Long-dated inventory balancing is performed each morning after the bulk of the<br />
bloods collected the previous day have been typed. It involves the part of tile flow<br />
circled at the top of Figure 5. The long-dated regional inventory which is expected to<br />
bccome available during that day is compared Lo the commitmcnt ol' units lor<br />
scheduled rotation shipments plus units required to meet open heart surgery needs<br />
(which is a specialized procedure where only fresh blood units are suitable). Any<br />
units in excess of these requirements are either retained to make up for shortagcs in<br />
stock-dated inventory as discussed above, or are made available for transshipment to<br />
other divisions of GNYBP. Since LIBS collects in excess of its needs', there is<br />
generally a surplus of rotation units especially in the more common blood types.<br />
Computer operation<br />
The effectiveness of PBDS depends upon accurate and timely data on operations,<br />
which is achieved in part by running the system on a niinicomputer, and by<br />
utilizing machine-readable bar codes on blood products and on test samples [ ]. The<br />
machine-readable codes on test samples are used in conjunction with automated<br />
equipment which performs blood type determinations and links the daita concernilng<br />
thc unit and its test results directly in the computer. This provides the earliest<br />
possible indication of what products will be reaching inventory during that day. The<br />
bar codes, which indicate product, blood type, identification numbers, etc., are also<br />
scanned as blood units arc shipped out and rctuirned, Lo maiilntainl perpttlul inventory.<br />
In this manner, the total inventory picture al the RBC is accurately maintained in real<br />
time.<br />
INTERFACES Novenlber 1979<br />
l~ ~~~~~-
- 319 -<br />
The light pen techniques are also utilized to control computer operations and lo<br />
identify the locations to which blood products are shipped or from wherc they were<br />
received. This is done by scanning bar codes on menu sheets that list all shipping<br />
locations, all types of transactions, and all available types of computer operations.<br />
This way, the computer is effectively used by nontechnical personnel, and any errors<br />
in entering data are minimized.<br />
In order to maintain a modular approach that can be utilized by all RBC's<br />
regardless of size, a network of miniconlpiuters is hcing used to h:ndic aHl the RBC<br />
blood processing needs. In a larger operation, such as LI3BS, thc operations are split<br />
functionally (i.e., separatc miniconiputers in the laboratory and disiribution arcas),<br />
while in the smaller centers a single minicomputer would handle all functions.<br />
Impact, Implications, and extensions<br />
Scientific in¡puct<br />
The successful operation of PBDS at LIBS has demonstrated the ability to set<br />
performance measures on the basis of regional planning. It establishes the first<br />
quantitative management guide for the selection of fcasiblc targets and slrategics. for<br />
the evaluation of options within a class of strategies, and for establishing the best<br />
possible performance within that class as a refercnce for the stratcgy selccted. It<br />
further demonstrates the ability to identify 4eviations from anticipated performance<br />
and, consequently, the ability to manage by exception.<br />
An example of this is the analysis of reported utilization by 28 HBB's that was<br />
performed recently. Statistical techniques indicated that the utilization rate pattern<br />
for 18 of the 28 HBB's were statistically not differentiable and showed an average<br />
utilization rate of 96%, which is close to the 98% value predicted; 6 HBB utilization<br />
rates were indicated as significantly below this norm and 4 utilization rates werc<br />
indicated as significantly above the norm. Since the same utilization rate is achievable<br />
for all HBB's under PBDS, deviations from the statistical norm can be confidently<br />
attributed to assignable causes. The utilization rates above the norm are<br />
attributed to sophisticatd techniques such as holding the same blood unit for several<br />
possible recipients concurrently. The poorer utilization performance of the 6 HBB's<br />
is attributed to poor blood banking practices such as failure to retum untransfused<br />
units to inventory promptly, or to special hospital practices.<br />
Management decision implications<br />
PBDS implies major changes in management decision `models both for the RBC<br />
and the HBB's. Most regions follow a procedure characterized by a decentralized and<br />
reactive distribution. In this mode of operation, the HBB checks its inventory status<br />
one or more times per day and, if it deems it to be low, places an order for additional<br />
blood. The RBC makes a decision whether its inventory is sufficient to fill the order.<br />
If it is, it delivers the requested quantity. If it is not, then it seeks to modify the order<br />
to a lesser amount, to substitute red blood celis for whole blood, etc. This "discussion"<br />
results in a modified order which is actually delivered. Both the HBB and the<br />
INTERFACES November 1979
- 320 -<br />
RBC are making short-term decisions regarding each delivery, sometimes with conflicting<br />
objectives and a,-e rcacting to a situation more than anything else.<br />
PBDS allows the system ¡o operate in a predictive distribution mode. In this<br />
mode the RBC assumes responsibility for the long-term scheduling decisions, while<br />
each HBB assumes responsibility for ihe daily finc adjustments. Thc RBC starts with<br />
a distribution stralegy as described abovc. A copy of this, in the form of a shipping<br />
schedule and recommended inventory levels to be maintained, is furnished to each<br />
HBB. The HBB inventory checking is then reduced to two steps. First, bcforc each<br />
scheduled shipment is due, any inventory a;bove the desired levels is returned and<br />
second, whcnever the inventory is insufficient to meet demand, a supplemental order<br />
is placed which is automatically filled under normal situalions since it is assumed that<br />
it is heeded immediately.<br />
The supplemental deliveries and thc returns are monitored over a two-week<br />
period, at the end of which period a decision is made based on the control statistics on<br />
whether or not to revise the distribution. This is a further example of how PBDS has<br />
achieved a management by exception principle.<br />
Economic inipact<br />
* The economic impact of PBDS can be most directly measured in terms of<br />
improvement in blood utilization. Prior to thc implemnentation of PBDS, thc utilization<br />
rate in the LIBS region was 80%, which was also then the national average.<br />
Since the implementation of PBDS, the utilization rate for LIBS has improved by<br />
16%, while the national average has improved litile if at all during tihe same interval.<br />
The improvecient in utilization at LIBS translates to 80% reduction in wastage, and<br />
therefore, to annual savings of $500,000 per year.<br />
Of lesser economic impact is the reduction in the number of deliveries. Before<br />
PBDS was implemented, an average of 7.8 weekly deliveries were made to each<br />
hospital, all of which were unscheduled; after PBDS was implemented, the number<br />
of deliveries dropped to 4.2, but of which only 1.4 are unscheduled. By associating a<br />
$10 cost to an unscheduled delivery to an HBB and a $5 cost to a scheduled delivery<br />
(which is part of a route), PBDS has achieved a 64% reduction in dclivEry costs. Thlis<br />
translales to annual cost savings of $100,000. Additional important, though less<br />
tangible, costs savings are achieved by the implementation of sounder blood banking<br />
practices to reduce discrepancies between actual and achievable performance for<br />
individual HBB's.<br />
Probably the most important savings in the national health care bill brought<br />
about by PBDS is realized by improved blood availability to patients. Since deliveries<br />
to the hospitals are mostly prescheduled, elective surgeries can be prescheduled<br />
also, so as to minimize the number of surgeries postponed because of lack<br />
of the right blood products. However, savings from this improved availability are<br />
extremely difficult to estimate and quantify.<br />
National implications<br />
It can be seen from the model of Figure 3 that, in order to achieve high<br />
availability and utilization rates for the rarer blood types (small usage), most of the<br />
INTERFACES November 1979
- 321 -<br />
shipnients have to be on rotation. In practice, however, RBC's can only schedule<br />
between 70% and 85% of the average blood collections for rotation shipments because<br />
of uncertainties in blood availability, and the need to keep an RBC reserve.<br />
Therefore, if thc amnount of rotational blood available for distribution is approximnately<br />
equal to that which will be utilized within the region (i.e., if u strict selfsufficiency<br />
criterion is applied), then for these blood groups either very low<br />
availability or alternatively a very significant rcduction iti utilization must he accepled.<br />
Since neithecr of these alterniatives is desirable, un alternative is to rotate nmore<br />
blood units in this blood groupl thal will be cventually transfused in the region and<br />
redistribute some portion of the returned blood units lo another region utilizing the<br />
inventory balancing techniqLues that wcrc described earlier. This is a feasible approach<br />
in LIBS since, like most regions thal are primarily suburban and rural in<br />
nature, it has the capacity for collecting blood significantly in excess of the overall<br />
regional needs.<br />
LIBS collccts approximaitely 20%/1 more blood than will be ultimately transfuised<br />
in the region. Virtually all of thc rarer bloods are first rotated to HBB's iii the region,<br />
while the excess collection in the more common bloods are mnostly immediately sent<br />
to the New York Blood Services (NYBS) division of GNYBP. This division encoiipasses<br />
the metropolitan New York arca and, like n1ost large urban arcas, has difficulty<br />
in collecting enough blood to nieet the needs of the imajor medical centers anid<br />
other hospitals in this area. The influx from LIBS is of significant help and the small<br />
fraction of older, rarer bloods thilt are reccived as stock-dated units can rcadily he<br />
absorbed. Thus the units collected in LIBS in excess of its own transfusion necds<br />
improves the quality of blood services in LIBS as well as in NYBS. On the other<br />
hand, the major medical centers in the New York Division of GNYBP also serve the<br />
needs of much of the population residing iii the arca covered by LIBS.<br />
It should be noted that not all major regions such as LIBS require interaction<br />
with larger regions. A planning exercise performed for the regional blood center in<br />
Richmond, Virginia, which services only seven HBB's, indicated that this region<br />
was remarkably self-sufficient. This is primarily because it includes a major medical<br />
center which accounts for a significant part of the regional usage. However, for the<br />
most part there is a.mutually beneficial interaction feasible between the smaller<br />
RBC's serving mainly suburban and rural arcas and the larger ones which will mostly<br />
service larger urban areas.<br />
These conclusions suggest that the concept of total regional self-sufficiency<br />
which has long prevailed in blood banking is in conflict with the goals of the Nutional<br />
Blood Policy that calis for high availability with efficiency. Rather, a modest level of<br />
resource sharing between regions as outlined above will work to the benefit of all<br />
participants.<br />
Extensions<br />
The success of PBDS has fostered a favorable climate for the further application<br />
of Management Science techniques both on a national and international basis. Thc<br />
International Society of Blood Transfusion Expert Committee on Automation has<br />
INTERFACES November 1979
- 322 -<br />
reccnily endorsed the concepts inherent in PBDS and the Swiss Red Cross Transfusion<br />
Service is studying it as a basis for the creation of a national blood distribution<br />
system for that country.<br />
On the national level, as the PBDS strategy is expanded to the other three<br />
divisions of the GNYBP, it will provide an opportunity to more thoroughly investigate<br />
a broader regional network. Concurrently, other regional blood programs are<br />
investigating the use of PBDS. The American Red Cross Blood Services - Northcasi<br />
Region has already implemented a distribution plan for its six RBC's based upon<br />
the PBDS concept. These implementations represent broader geographic groupings<br />
of RBC's which, together with other such groupings, could eventually interact<br />
through a hypothetical national blood clearinghousc.<br />
Such developments would contribute significantly towards meeting the objectives<br />
of the National Blood Policy. It would act to alleviate the "national blood<br />
shortage" which, in part, at least is thought to be not so much a national blood<br />
shortage but rather the lack of a national logistical system for moving blood from<br />
where it is available to where it is needed. They would thus contribute to a reduction<br />
in the consumer's hospitalization costs and the delivery of higher level health care.<br />
Acknowledgements<br />
We are indebted to Aaron Kellner, M.D., President of the New York Blood<br />
Center, Inc.; Johanna Pindyck, M.D., Director; Robert Hirsch, M.D., Medical Director<br />
of the Greater New York Blood Program; and Thcodorc Robcrtson, M.D.,<br />
Director of Long Island Blood Services, for their wholehearted collaboration and<br />
encouragement. We are also grateful for contributions made by Professors Cyrus<br />
Derman, Ed Ignall, Peter Kolesar, and Donald Smith of Columbia University, at<br />
various phases of this work, and for helpful comments and encour4gement provided<br />
by Professors Howard Kunreuther, William Pierskalla, and Morris Cohen of the<br />
University of Pennsylvania.<br />
This research was supported in part by the National Institutes of Health, National<br />
Heart, Lung and Blood Institute Grant No. HL 09011-16 at The New York<br />
Blood Center.<br />
REFERENCES<br />
t11 Brodheim. E., "Regional Blood Center Automation." Transfusion, Vol. 18, 1978. pp. 298-303.<br />
[2] Btodheim, E., Hirsch, R., and Prastacos, G. P., "Setting Inventory Levels for Hospital Blood<br />
Banks." Transfusion, Vol. 16. 1976. pp. 63-70.<br />
1[3 Brodheim. E.. Derman, C., and Prastacos, G. P., "On the Evaluation of a Class of Inventory<br />
Policies for Perishable Producis such as Blood," Management Science. Vol. 21, 1975, pp. 1320-<br />
1326.<br />
[4] National Blood Policy, Department of Health. Education and Welfare, Vol. 39. 1974. 176.<br />
[51 Prastacos, G. P., "Optimal Myopic Allocation of a Product with Fixed Lifetime," Journal of the<br />
Operational Research Sociery. Vol. 29. 1978. pp. 905---913.<br />
[6] Prastacos, G. P., "Allocation of Perishable Inventory," forthcoming in Operations Research. Also<br />
available as Technical Repon No. 70, Operations Research Group. Columbia University. 1977.<br />
[7] Prastacos, G. i. and Brodheim, E., "A Mathematical Model for Regional Blood Distribution."<br />
Working Paper 79.02-91. Depanment of Dccision Sciences, The Wharton School. University of<br />
Pennsylvania. 1979.<br />
INTERFACES November 1979
- 323<br />
THE CREATER NEIW' YORK BLOOD PROCRAM ¡<br />
The New York Blood Center ' American Red Cross<br />
Dr. RaJ Nigam<br />
RCA<br />
David Sarnoff Research Center<br />
Princeton, New Jersey 08540<br />
Dear Dr. Nigeam,<br />
310 Esst 67 Street. New York. N Y. 10021. 794-3000.<br />
August 3, 1979<br />
The Greater Newv York Blood Program,the largest blood program in the world,<br />
has assumed the responsibility for the blood needsof 18 million people<br />
residing in New York City and in much of its surrounding area. We recruit<br />
people to donate their blood, collect this living tissue from them, process<br />
it in our laboratories and distribute it to the 262 hospitals in our community<br />
vhere it must be available to care for the people in need. Our aim is to have<br />
enough blood of the right types on hand to meet the usual hospital demands and<br />
the emergencies vhich may arise, but not so much that it vill be vasted since<br />
blood can only be stored for 21 days outside the body. We face the major<br />
problem of hov to maximize the availability of blood to each of the 262<br />
hospitals that ve service vhile effrectively discharging our implicit covenant<br />
to our donors to see that their gift is efficiently utilized.<br />
We turned to management science to help us achieve this goal and provided<br />
the Long Island Blood Services Division of our program as a test site. The<br />
system that vas developed has been in operation for two years. It integrates<br />
the blood supply of a region by developing a complex pre-planned rotational<br />
system so that the availability of blood of all types becomes the ssae in<br />
hospitals regardless of size and usage, and utilization of the blood also<br />
becomes the same.<br />
Patients in the community have equivalent protection for blood services at all<br />
the hospitals vithout burdening some of them vith excessive vaste. This system<br />
has given us a mcechanism to do exactly vhat ve urgently needed - Takc the Crisis<br />
Out of Blood Banking. We have offered to our hospitals a rational, effective,<br />
functioning system - vhich vill soon be extended both throughout our service<br />
area and elsewvhere i the United States and abroad. It is not unfair to state<br />
that this program can and vill contribute to an improvement in health care<br />
throughout our nation, and therefore touch each and every one of us at some time<br />
in our life. We are proud of our achievement and appreciate this recognition.<br />
JP:ck<br />
I -<br />
Sincerely,<br />
Pindyck, N.D.<br />
ie President snd Director<br />
The Greater New York Blood Progrsa<br />
I ' ls - -II - IP B - - - -· ~·s~WI<br />
INTERFACES November 1979
"'1 .'.<br />
- 324 -<br />
Using Computer Simulation<br />
to Predict ICU Staffing Needs<br />
by N. Duraiswamy, R. Welton, and A. Reisman<br />
Tis aricl dacritbe a compurt imubdon study to deiwufs<br />
¡he ambr oM!f fuff-¡u ;te:t d nmra sequdt<br />
to ddv~r afe nur h a 20.had medical<br />
_Lawev mr usat n Le asheonr' compua dmul~ion<br />
madd p d/ffwu, stafrdu r i* /for two sLr-<br />
MIh* lo np a e aborot~l he.ao tMhe w<br />
ddi wn am omplhd ad ndisuahe dost omd<br />
/fffO, f/ ,, o, t dmt loa ohr e t.<br />
ami~p.<br />
The rfi nutning cervi.e stadrd of the Joint Commisaioa<br />
cm Acdliuati of HoSptir (JCAH) cabll for "a<br />
fflca mnumber of duly iUcnsed rqlered nures on<br />
dry all en a ... to live patient the nurnin car<br />
timt mq~ir the judgmant ud pcilkted sklil of a<br />
_ ~tr au m"ll¡1. Many rect muanmcnt dudk-1<br />
4e a mued tn to define how many nurnes consImuem<br />
a ufllciem ?umbur.<br />
m qh aay bpita, nurdn rnaffins is done -lmost by<br />
tidon;a~ maa addas, wbrmt. and r aem.,la<br />
taff on the baais of a ubjective prception of what<br />
msems o~siary. Nurs are often reaacned from noto~uy<br />
uare to cover busy ars$l5. However, in thc<br />
mitlve cue unlt (ICU). whau ou must be knowlodgab<br />
a caxtive, observant, diQnostic, and therapWdc<br />
daona of altial care(6), reasniln nunrcs<br />
from other au~ can jeopardlte c unit's standard of<br />
are. Ths intuiti approah to rtafMng al o difficult<br />
N. O. D , PaD., ik iata porI or Of bulesa m ladr<br />
Uam V, Ko. .k ~recdd u MS. md Ph.D. la opea<br />
da_ mrerb kr~ Cau Wemua Ium Ui vduy.<br />
IL Wll, LNR., IM. LN., bk a m,~t dese ~uind e lba e n Prono<br />
P~ lid Sodd do Nl~ . Can Wqm a~maere U-ailty.<br />
A. l5m , P.D., P., kL pmomw o<br />
Wmm Iammw Umial~y.<br />
o opa~i rtuar., Cmu<br />
*19SI The Jounml ot Nunda Admitnmiwn<br />
Thb Joural of Nwiqa Admimmu / Feb~ruy I1N<br />
ID translp i to quantifiabl terms that are uaderstandable<br />
to othrs, including hospital administrators, boards<br />
of trustees, and other nurses.<br />
This article describes a system-analytic study of the<br />
nurse staffing needs of the Medical Intensive Care Unit<br />
(MICU) at the University Hospitais of Cleveland. la<br />
consdering how to determine the efficacy of various<br />
staffmrn alternatives, we decided that a computer simulaion<br />
woud be the best method. Computer simulation<br />
acraes a computer version of the real system and provides<br />
laboratory conditions in which decision makers<br />
can tet lternative policies. Simulation allows the testing<br />
of muffina choices in the light of the conflcti~g<br />
objective of cost continment and quality of care.<br />
Morcover, it allows consideration of variations in patient<br />
admission and discharge ratcs, lesnth of stay,<br />
leves of acuity, and levels of nursing care requirements.<br />
Traditional assessments for staffing<br />
Syutematic mcthods for staffin8 have taken several approche.<br />
One approach takes such dements as diet,<br />
toileting, vital sign measurement, respiratory aids, hyiene.<br />
suctionn,. and turning and/or positioning(7-9)<br />
and applie a wcigbted point *ystem to these uarcas of<br />
care. Ihe point total is then converted to some unit<br />
equlvaat o a specific amount of nursing care time.<br />
Other approaches have lumped all care categories tother<br />
and subjctively established required levels of<br />
care ranfin8 from hih to minimal(0l] without def'ning<br />
the criteia to be used. An "hours per patient-day" formula<br />
multiplies the number of patients by standard<br />
houn of nunin care, such as 5.0 per patient, and then<br />
multiplies this total by 7 to obtain the required hours of<br />
nutinl care per week. Another approach uses patient<br />
care categoric such as minimal care, partial care, modrate<br />
care, complet care, and intensive carell 1-131 but<br />
includc criteria for indirect ad supportive elements of
_,~ .-<br />
- 3. 2- -<br />
TABLE 1. PATIENT CLASSIFICATION<br />
Ca Re Aummt : : Wmd Poes .o4rdilnO to LCr<br />
Cl'"'y ' ", '<br />
.ol tCue<br />
Intse HIlgh Moderaot e Minimal<br />
Physlcal Dp-idan~ 2.4 1t48 11. 4<br />
Obwvakn .8 19.6 OA<br />
8octEmot,~loal Ce 2a0 18.0 10.8 4.<br />
RshFIIUorTeaCNno 22.0 1L2 924 4.4<br />
the nursing process, thus allowing a comprehensive asscssment<br />
of actual care required. Such a comprehensive<br />
approach forma the basis for the patient clasification<br />
ysiyem developed a University Hospitals of Clveland,<br />
and this approach was used in the study described here.<br />
Baekgrlound<br />
¡be University Hospitals of Cleveland include a<br />
1000-bed ;ace c medicl center located on the easi<br />
aíde of the city of Cleveland. lts aix specialty hospitals,<br />
il umd om cnra maamet, are closy afrilated<br />
with theb profesional and graduate schools of the healih<br />
adc disciplnes of Case Wern Reserve Univerity.<br />
Tle Medicael Itensive Care Unil (MICU) of Univerity<br />
Hospital conlir0 of two patent care arueu: thc intmelve<br />
cm unit (ICU) where crically ill patienut are<br />
biitally admitte and cared for during the acute tage of<br />
their illns, and the progrceive care unit (PCU) where<br />
p~rtls ar e cared for lfter the acue stae of Iheir illnm.<br />
Both units were desigpd to accommodate 10 patins<br />
ecah with 10 single roomr in the ICU and 5 double<br />
roomu in the PCU, yielding a total posible census of 20<br />
patient for the MICU.<br />
After the firt year of operation at 100 per cent occu-<br />
TABLE 2 PATIENT CARE CATORIE8<br />
ACCORDIN TO TOTAL POC 8CORE<br />
To~ PO 8Moe CdaMV<br />
80or dox,<br />
m0a40<br />
o.~ 40<br />
Mt~-<br />
.~Modmmm<br />
mlml<br />
pancy, the 44 budgeted full-tinic nursing positions<br />
proved to be inadequate to provide safe nursing care in<br />
both Ihe ICU and PCU when both were at 100 per cent<br />
occupancy. For this reason, 4 beds in the MICU were<br />
closed to patients, reducing the total possible census<br />
from 20 to 16 patients for both units. We undertook our<br />
study to determine how the original 20-bed unit could be<br />
restored without resorting to overstaffing or understaffing.<br />
Data collection<br />
We used the department of nursing's Patient Care Categorization<br />
(PCC) assessment tool, with the charge<br />
nurse as the source of data. This classification system<br />
uses four categories of care requirements: physical dependency,<br />
observation required, social/emotional requirements,<br />
and rehabilitation and/or teaching requirement.<br />
Within each of these categories, there are four<br />
levels of required care. The charge nurse chooses which<br />
level of care each patient requires within each of the<br />
four categories.<br />
A total acore, called a PCC score, is then obtained by<br />
adding weighted points for the level of care chosen in<br />
each category. (See Table 1). Based on the ¡otal PCC<br />
acore, a patient is assigned to one of four care categories.<br />
Table 2 lists total PCC scores and their corresponding<br />
care categories.<br />
Using thesc four categories, the nursing department<br />
developed the policy for nurse-patient assignments<br />
(Table 3). This policy provides adequate patient-nurse<br />
rations to ensure safe care and is currently used for<br />
nurslng assignments in the MICU.<br />
The PCC tool had been in use for two years prior to<br />
this study. During that time, ihe PCC assessment was<br />
done one week of each month on the 7:00 A.M. to 3:00<br />
P.M. shlft by the MICU charge nurse; this sample was<br />
The Journl of Nun'in Admitbttion / February 1981
_;-inarP - - i - i ,_I<br />
found to be representative of data obtained from initial<br />
daily assessments using the PCC tool. Wc computed the<br />
probability of a 'atient's being in. a specific care category<br />
and the nim ber of patients in a specific care category<br />
per day. 1. ing these data, which spanned two calendar<br />
years, w, identified seasonal variations, such as a<br />
greater numbez of admissions of patients with diagnosis<br />
of drug overd -se or myocardial infarction during the<br />
spring and sur. mer months.<br />
The Daily E atient Census Forms for the ICU and<br />
PCU were usec on a sampling basis to obtain admission<br />
The Jomeal d NWnY4 Mmisuun.i IA Fe~uay I11I<br />
- 326 -<br />
FIGURE 1. FLOW CHART <strong>OF</strong> THE SIMULATION MODEL<br />
and transfer or discharge data. The sampling included<br />
al patients admitted on 112 randomly sdelcted days over<br />
a onc-year period (1977-1978) to determine actual<br />
Iength of stay in both units. It was feldt that this approach<br />
would provide a statistically significant sample<br />
yet minimize data collection time and effort. We then<br />
used this data base to determine the length of stay distribution<br />
in our simulation model.<br />
There is a significant fluctuation in the daily patient<br />
load in the MICU. Consequently, one would exppet a<br />
similar fluctuation in :"s daily nurse staffrang nceds. The<br />
| LENGTH <strong>OF</strong> STAY<br />
-- - DISTRIBUTION
TABLE 3.<br />
MEDICAL INTENSIVE CARE<br />
UNIT (MICU) POUCY<br />
FOR NURSE-PATIENT ASSIGNMENT<br />
- 327 -<br />
Nue.patlent aslgnment wlll be made In temis of<br />
pallent PCC ecore and wlll comply wllth ihe core and<br />
nuepatient ratlos alletd below.<br />
Patent Catm<br />
Catogory Score<br />
Intense<br />
HNh<br />
ModSate<br />
Minimal<br />
NurcePatlent Ratlo<br />
1:1<br />
1:1<br />
1:2<br />
'3<br />
The above &aalgnment policy la applicable lr all ahilis<br />
in bolh hb ICU aud PCU.<br />
patient mix in addition to patient load determines :he<br />
staffing requirement, but the random arrival of patients<br />
and the random length of stay suggest that the patient<br />
mix probabilities may not vary every day.<br />
The simulatien model<br />
Fgure I ilUustrates the simulation model. Patients are<br />
admitted to the ICU for a certain length of time, as determined<br />
from the length of stay distribution for ICU.<br />
At the end of this period, they are edher transferred lo<br />
PCU or dichuared. The length of mty of the patient in<br />
PCU is aiain determined, using the length of stay distrib¡tion<br />
for PCU.<br />
Since no additio of beds is planed for either the<br />
ICU or PCU, capacity constaint at the current ten-bed<br />
lecL for each unit have been imposed in the model. Accordil4<br />
to current practice, when all beds are occupied,<br />
thbe let sick patient is transferred from the ICU to the<br />
PCU in order to admit a newly arrived patient. When a<br />
siair situation arises in the PCU, the least sick patient<br />
la transferred out of the PCU. The simulation model<br />
coalam tbe blsic to hade tbee úguations.<br />
The nursing cae requirement for each patient i¡ expred<br />
in terms lin and of ou ente the simulation<br />
model to determine the total nursing care hours needed<br />
in a shift. The model asmumes that patients in an intensive<br />
care setting wih require the mame level of care during<br />
the otber two shifts of the day.<br />
The simulation covera a full year. We designed the<br />
imulation modal to print out the number of nures<br />
neaeded on each simulated day during the one-year<br />
paiod. lao ddition, the model generaed descriptive statistical<br />
information about the average number of nurses<br />
required u well u the standard deviation for any<br />
chosen period of time (Figure 2a-d).<br />
Validity of the model<br />
The simulation model was validated using the historical<br />
data base from the MICU. The simulation results are<br />
therefore valid for prescriptive purposes if the utilization<br />
patterns do not change. However, if the utilization<br />
patterns are projected to increase or decrease, the simulation<br />
can be used as a vehicle to develop new plans for<br />
staffing.<br />
Analysis<br />
The total number of patient days for both l..e ICU and<br />
PCU is 308 as determined by thc analysis of 112 randomly<br />
selected days during a one-year period. The patient<br />
mix probabilíties used in this study are shown in<br />
Table 4. hbe values for patient mix probabilities were<br />
obtained. trom the data collected by the department of<br />
nursing over one full year during 1977. The patient mix<br />
probabilities for the winter, spring, summcr. and fall<br />
seasons wcre obíained separately to capture seasonal<br />
variations in the staffing needs. During the course of the<br />
study, data on the patient mix probabilities were collected<br />
individually for both ICU and PCU through direct<br />
observation. However, these individual data werc<br />
not used for the simulation because the nursing care required<br />
for a patient is the same in each unit for each patient<br />
category.<br />
Staffing by seasonal demand<br />
As evident in Figure 2, the variation in staffing requirements<br />
between fall and winter months is not significant.<br />
The average requirements for spring and summer were<br />
identical with only a small difference in the standard deviation.<br />
However, there is a notable variation in staffing<br />
requirements between the combined fall/winter and<br />
combined spring/summer periods. These results indicated<br />
a need for two staffing levels, each for a sixmonth<br />
period. Since there is no specific staffing level<br />
which meets the staffing requirenent optimally on each<br />
day of the six-month period, we offered the data in Tables<br />
5 and 6 to show the percentage of days of overstaff-<br />
TABLE 4. PATIENT MIX PROBABILITIES<br />
.... ,, ' '.'' . POAB '<br />
etiCos<br />
kI~<br />
wihn Who,<br />
0.31<br />
. .. Sum;i, .<br />
0. 0 ' '<br />
a.::<br />
;' '0 04.3 '<br />
_ ;ode 033 0.12 0.18 0i0<br />
;Minknoa 0.13 0.03 0.02 0.13<br />
I hc Journal uo SNui\ln F AdJmnmlnmtr¿atn Ihraiy / 191
ing and understaffing associated with each staffing<br />
level. This information allows management to weigh the<br />
impact of alternative staffing levels against cosís and at<br />
the same time to comply with HSA and JCAH standards.<br />
Scheduling complications<br />
The average staffing levels of 30 nurses per day for fall<br />
and winter and 36 nurses per day for spring and summer<br />
appear most desirable in terms of overstaffing and<br />
understaffing. The large turnover of nursing staff during<br />
the spring and summer months (approximately 15<br />
terminations or transfers out of the MICU between<br />
March and September of 1977)1161 may have have implications<br />
for scheduling vacations for experien..<br />
I<br />
lo<br />
00<br />
c. F mr (Augul)<br />
a 10 lo la 25<br />
DOY<br />
Ibe Journal oí unran Admenut l Fwbrlwuar) #lvTI<br />
- 328 -<br />
- I -·V - i--<br />
FIGURE 2. SEASONAL M.CU<br />
NURSING STAFF REQUIREMENTS<br />
-<br />
* ^4W : 38<br />
810. Der. ' 2<br />
nursos. Ncw graduate orientation to the MICU and education<br />
in critical care, which also occur during spring<br />
and summer can increase the average number of nurses<br />
needed during these months.<br />
While the simulation resultod in recommended staffing<br />
of 30 or 36 nurses per day, levels which are lower<br />
than the actual budgeted staffing (44 full-time nursing<br />
positions per day) for the MICU, several considerations<br />
must be noted. First, the staffing levels suggested by the<br />
model do not include provisions for vacations, days off,<br />
holidays, illness, absenteeism, and staff development<br />
commitments. Second, the staffing recommendations<br />
apply to situations in which every nurse is experier, -d in<br />
critical care, has successfully completed the entire ICU<br />
orientation, and has demonstrated safe, indc-endent<br />
¡<br />
1 O.<br />
80<br />
4O<br />
20<br />
t0<br />
'llo~~~ ~Std.<br />
AWae : 3JO<br />
DeW. : .S<br />
MtulnYm: 42<br />
5<br />
Fell (NOvmb<br />
0 1S<br />
%Y<br />
20 25 30<br />
W_
Nursing Stalf Level<br />
(i of nurss/day)<br />
26<br />
28<br />
30<br />
32<br />
34<br />
Nursing Stafl Level<br />
(I of nurseacday)<br />
30<br />
32<br />
34<br />
38<br />
38<br />
.40<br />
- 329 -<br />
... , I I I I<br />
I _i<br />
TABLE 5. ANALYSIS <strong>OF</strong> STAFFING LEVELS (FALL AND WINTER)<br />
% of Days of<br />
Overstatffing<br />
18.8<br />
37.2<br />
39.4<br />
58.8<br />
72.2<br />
% of Days of<br />
Understaflfing<br />
81.2<br />
62.8<br />
41.2<br />
41.2<br />
27.8<br />
TABLE 6. ANALYSIS <strong>OF</strong> STAFFING LEVELS (SPRING AND SUMMER)<br />
% of Daya of<br />
Overtaffling<br />
5.6<br />
15.6<br />
27.8<br />
28.9<br />
52.2<br />
71.7<br />
practice without close supervision. Finally, the recommended<br />
stuaffing levels are for fully qualified nurses for<br />
dircm patient care; thcy do not include provisions for<br />
ICU nurses away from the bcdsidc involved in administrative,<br />
educational. o* tsther indirect patient care activities.<br />
Costa of tLe atudy<br />
Since this study was conducted to fulfill academic requiinmets<br />
to study real-life problems, there were no<br />
out-of-pocket couts for development of the model and<br />
its ooinmputer implementation. Data collection, analysis,<br />
cmiputer programming, and computer tíme expenses<br />
would occur in other settings. Nursing time used for<br />
collection of data used in this study was approximately<br />
rive minutes per day for seven consecutive days each<br />
month. However, this responsibility has bcen a regular<br />
pat of the MICU charge nurse role for several years.<br />
Data analysis and programming of the simulation<br />
model required less than one person month.<br />
Applying ihe computer simulation<br />
la other sietdis<br />
Although this study was carried out in a large urban<br />
medical center, Ihe same approach can be used in small<br />
community hospitais. A staff of inhouse cngineers anJ<br />
prorammers i not n:csury. Small community hos.<br />
pitais with access lo local universities can use universitybased<br />
expertie to perform such studies. Moreover,<br />
many public or private universities are looking for reallie<br />
experiences for both faculty and students and will<br />
often perform sludies on a gratis basis.<br />
The seasonal variations in ihe dita collected from a<br />
% of Days of<br />
Understafflng<br />
84.4<br />
84.4<br />
72.2<br />
4".8<br />
47.8<br />
2S>3<br />
single institution should be considered illustrativc only.<br />
The approach, however, is transferrable to other instituiions,<br />
other services, and other seltings.<br />
References<br />
S of Days of<br />
Optimum Staff<br />
o<br />
O<br />
19.4<br />
o<br />
o<br />
% of Days of<br />
Optimum 5.1ff<br />
10.0<br />
o<br />
o<br />
23.3<br />
O<br />
o<br />
1. Accredrod ion Moanualfor lIospitols. Joint Commission on Accreditation<br />
of Hospitais Chicago. 1973 (updated).<br />
2. Ryan. T.. Barker, 8. L.. and Marcianto, F. A. A system for determing<br />
appropriate nurse starfing. J. Nurs. Admin.. 5(S):30-38.<br />
1975.<br />
3. Norby, R. B., Freund. L. E.. and Wagner. B. A nurse staffing<br />
system based upon assignment difficulty. J. Nurs. Admin..<br />
7(9):2-24. 1977.<br />
4. Clark. E. L. A model of nurse staffing for effective patient care.<br />
J. Nurs. Admin.. 7(2):22-27. 1977.<br />
5. Norby. R. 8. ec al. 1977. pp. 2-24.<br />
6. Burrell. A. L.. and Burrell, L. O. Criricol Core. Si. Louis: Tlhe<br />
C. V. Mosby Company, 1977.<br />
7. Clark. E. L., and Diggs. W. W. Quantifying patient care needs.<br />
Haspiras. J.A.H.A.,. 9:96-100, 1971.<br />
8. Poland. M., el al. PETO: A systein or assessing and meeting pa.<br />
tient care needs. Am. J. Nurs., 7:479-1482. 1970.<br />
9. Willilms, M. A. Quantification of direct nursing care activities.<br />
J. Nus. Admin., 7(8):15-18. 1977.<br />
10. Heara. C. How many high care patients: Deployment of nursing<br />
utaff. Nursing Times, 17:504. 1972.<br />
II. Norby. R. 8. a al. 1977, pp. 2-24.<br />
12. Phipps. W. J., and Philps, C. Definition of Terms Used lo Classify<br />
Patiens According to Their Nursing Care Requirements. Departnent<br />
of Nursing, University Hospitais of Cleveland. 1977.<br />
13. Pardee, G. Classifying patients to predica staff requirements.<br />
Am. J. Nurn.. 3:517-520, 1968.<br />
14. Zleers. L. J. Calculating a nurse staffing budget or a 20-bed unit<br />
at 100%e Occupancy. J. Nuns. Admin.. 7(2):11-14. 1977.<br />
15. Newman. M. A.. and O'Brien, R. A. Experiencing the research<br />
process via computer simulation. Image. 10:5-9. 1978.<br />
16. Alekn, M. Annual Rportn. MICU. Unpublished paper. Dcpart.<br />
ment of Nursing. Univerity Hospitals of Cleveland: 1-6. 1977.<br />
I hc Journal of Nurnms Adn:initration; February 1981
1 9<br />
Michael B. Harrington Forecasting Areawide<br />
Demand For Health Care<br />
Services: A Critical<br />
Review of Major<br />
TeChniques And<br />
Their Application<br />
Since well before Cassandra, people havc<br />
sought to forecast the future. In modem times,<br />
forecasting methods have adopted fairly scientific<br />
guises. But it is not clear that their predictive<br />
accuracy has improved appreciably over<br />
.hat of their predecessor. This is especJally<br />
utre of methods applied lo large-scale public<br />
problems, such as areawidec health planning.<br />
Improved methods have been offset substantially<br />
by the greater complcxity, more rapid<br />
change, and more pervasivc interdependence<br />
characceristic of modern society. Forecasting<br />
skill have grown, but so has the difficulty<br />
of the ¡;.',.<br />
The impetub for developing improved methods<br />
for use by areawide health plannera, begun<br />
nder tbc Comprehensive Health Planning<br />
lesilation of 1966,' no doubt will be reintorced<br />
by the Health Planning and Resources<br />
Developmct Act of 1974 (P.L. 93-641).2<br />
M1mut . Hia po~ i D, bs Senior Auociat ltot<br />
the Sysclm Evaluallon Departnen, CACI. Inc.-<br />
Federal (Arlaliton, VA 22209), and Professor of<br />
ialth Economcs, Souhetemrn Unlveity.<br />
fai marerch or thbis piapr w completed under<br />
Contract liA 230-76.00~ aeored by the Bureau<br />
Healthb Planaing aMd Rmurces DevelopmcnM.<br />
Health Resources AdminiArítion, DHEW. In de.<br />
veop~n ibs par, Ub aubhor benited grealy<br />
(mam prticipatíAon ia eries o( three ympoi~ Wpon.<br />
ored by thibe Bureau of Health Planning d Re.<br />
bouets Developenl, DHEW. durinl the fali of<br />
1974 und prling of 1975. Of coun. neither BHPRD<br />
anr tib other rympoml paricipans are responlible<br />
for shorioominp thir paper may cntain. In additbn.<br />
aluable crituncsm was rendered by Sarh P.<br />
Far of the WAublni Office of Arthur Young<br />
& Comniay; Wiliam Orfes. Dcprnment ot Medci.ne<br />
and SurUlry. VA(Mas Admnlnt(mbul . WuashJion.<br />
D.C.; and Dr. Chester McCall. Manager. Syucms<br />
Evaluation Dcpanmen, CACI. Inc.-Federnl Arlingl<br />
to. VA.<br />
- 3 30 -<br />
__ ______________ ______<br />
Somewhere betwcen perfect forecasts of the<br />
health care futurc and none at all lies a "zonc<br />
of feasible forccasting" (i.c., forccasts both useful<br />
and within the capabilities and budgcts of<br />
health planncrs). This paper explores the zone<br />
of feasible forecasting, by considering the following<br />
points:<br />
O The objectives of forecasting in areawide<br />
health planning;<br />
0 Specific factors contributing to thc demand<br />
for health services that enter into any serious<br />
forecasting effort;<br />
O Major sources of change and continuity in<br />
the areawide health care system that are<br />
identified in conjunction with demand forecasts;<br />
O Six generic kinds of forecasting techniques<br />
in the health planning context, including<br />
an evaluation of the strengths and weaknesses<br />
of each;<br />
C A simple framework through which each<br />
forecasting method might be brought to<br />
bear most effectively;<br />
o Some apparent dimensions of the "zone of<br />
feasible forecasting," given the current state<br />
of the art.<br />
Objectlves of Effective Forecasting<br />
At least three major objectives for forecasting<br />
areawidc health service requirements recur in<br />
public discussion:'<br />
1 Improving the foresight and skill with which<br />
public and private health care resources are<br />
allocated. Improved forecasts would help<br />
achieve lhis objective primarily by providing<br />
an arcawide "picture" of future necds<br />
1
Table 1. Factors ¡i denad for medical care*<br />
- 331 -<br />
Foecuing Health Core Servnic<br />
Fadcon afieelng a Faton affecting Healt h vkl<br />
pfhedm'd'da.and for pbyddau' prel~ ualy demade ed<br />
berth ernks d albetb tneaices m · resul<br />
1. Incideace of ilne or injury . Patient chamctcrisia. including 1. Physician cae in an of fice or<br />
2. Severity of iliness or injury relative cost to the patient of other outpatient setting<br />
3. Cultural values and atitudes using different health services 2. Emergency care<br />
4. Demographic factors 2. Physician's institutional 3. Inpatient hospital care<br />
5 Costa (tactorn affliatiluons 4. Referrals to apecialized ervices<br />
J. Cast fab~cío ~ 3. Physciar's knowledge and long-trm care facilities. or<br />
6. Perceived accessibility. actitudes other care-giving institutiona<br />
availability aad convicnicncc 4. Relative costs to physician of S. Home health services<br />
of service provider prescribing alternative health<br />
7. Family. peer group. or other services<br />
authoritative pressure 5. Ava·ilbility of prescribed or<br />
8. Life stylc facions affecting desired services<br />
health<br />
These factorn are not necessarily ranked in order of imponrtance.<br />
an, demanda into which public and private<br />
objc.ives can be harmonized.<br />
2 A'pneating both quality and cat control<br />
in medical care. Improved forecasts would<br />
do thib by helping to avoid both alltion<br />
of "excesaive" community recourcer to some<br />
halth servic in the future, and the allocatio<br />
of insufficient" resources to others.<br />
3 Anticipatin Wnd planning for the impact of<br />
deveopiag tchnology and chag·ln method<br />
of organizatioa upon the health care<br />
spatea'<br />
These are ambitious objectives. Many argue<br />
tha bey are won uabitious for exi~iag forecastia·<br />
techniquea, that ourt u skilis are<br />
too limitd to achieve them. Thi paper explores<br />
this question in greter depth.<br />
C Pf Cfodb so b Dead<br />
fo Ham~ SeIrve<br />
"Need" and "demad" have recived considerable<br />
ateatioa in the litertum. TbI paper<br />
conccntrta upon the concept of demaud, the<br />
more tracable ol the two no frm fra a forecauing<br />
viewpoint.* Demad for health servia<br />
-g erally defind u the aount o serviesa<br />
actually used by indiidu in the commuaity<br />
-- a tuneioa d a oumber of economic , socil,<br />
pbycal and envioramml froa (cc<br />
Tale 1). Tbe. fason ae simgficat in any<br />
comprehensivc forcas o requirema for<br />
particular health services. But taken together,<br />
they presenat formidable problems ¡o the forecaster.<br />
Frt, the nature of each and the<br />
interaction among them are difficult to determine<br />
with pr~eion, especially ona an areawide<br />
basis.' Moreover, the influence of les<br />
readily measured variables ii Table 1 (eg..<br />
peer group pressure, perc:ived accessibility)<br />
is very poo~ly understood from a predictive<br />
standpoint. Ssond, the importance of tbe<br />
two cdlumm varis in term of r Jainflu- ve<br />
ence upon service demand. Pacton in the finth<br />
columa tend to be more influential in thd demand<br />
for mergncy ad ambulatory services,<br />
tor example, while facton in the second column<br />
asumc greater importance when forecasting<br />
demand for inpatient and long-tenn carn.<br />
Third, the rlaive contribution madc by eotora<br />
wilhin each column is different from service<br />
lo srvic. Pamily or peer group pressure,<br />
for exmple, tends to be very ignifiant<br />
in the demand for long-term care, but less<br />
important in cmergency care situationa.<br />
To be fully useful, bowever, forecatiog<br />
techuiques should be able to deal with these<br />
demd-oriented complexities in a reasonably<br />
effective way.<br />
Ma Suoas dl Cofa Choa~e ad<br />
Cad k A cdqt Daem d for Seuice<br />
Miky fmaon Etmin demud ur<br />
e fidy m«ble,<br />
p _ticuilly in tbe bort nm. OtbeaM m ma
Inquiry/Volume XIV., September 1977<br />
- 332<br />
TabMe 2. Possible sowues of change and continuity in the communily health care system<br />
Soures of change<br />
1. Overriding problem(s);<br />
examples include:<br />
* Improving quality of care for aekcted<br />
target populationa<br />
* Gaining control over runaway costs<br />
* Redefining the balance of interestr between<br />
providern and consumenr of health care<br />
servics<br />
* Broadening access to care for selected<br />
target poputationa<br />
* Ovcrcoming fragmentation of service<br />
delivery palterns<br />
2. Prime Movers;<br />
examples include:<br />
* Medicare. Medicaid<br />
* Blue Cross. Blue Shield<br />
NHI, it enacted<br />
* Associationa of health care professionala<br />
(eg.. AMA, AHA, ANHA, etc.)<br />
· PirIO*<br />
volatile. When forecasting, it may be useful<br />
to etimate commuahty forces promoting change<br />
afiJ encouraging preservation of the nsatus quo<br />
i thdese factorn. Some commonly advocated<br />
stracgies include:'<br />
Forecetnlt Major Sowuce ol Chanse:<br />
A least w readily identified hitiaon d rof atifcamt<br />
chanp in the health ca system are<br />
sucepqible lo amalysis using one or mae of<br />
ti. lorecaf _l techaiques to be evaluated in<br />
Ihe exit sciohan:<br />
O T/1 OverrldMin Problem(s):. ldentify and<br />
evaluate thbe problm(s) tadng the com<br />
munity heath care yrtem thim re widAly<br />
thought to require solution ad thit, i<br />
"solved," wil result ia signif~nt chlagls.<br />
Por a sample of conmmoa probrs, mee<br />
Table 2.<br />
O The Pri~ Movrs: Identity and evaluate<br />
thase inmtituioas ad proceaes that strongly<br />
and indepemdtndy affect the way health<br />
car: is delivered (see Table 2).<br />
Forecasfta Malor Srces o0 CotLnulty<br />
Whil re me aspecs 'of the blth care system<br />
will chane within the plbaaal dme frame,<br />
perhaps dranatically so, most wlU notL It often<br />
Sources of continuity<br />
1. Organizational and demographic superstructure;<br />
examples include:<br />
* Instiiutional and professional licensure<br />
requirements<br />
* The complex of other federal, state. and<br />
local regulationa<br />
* Longestablished federal, state, and local<br />
financing programs<br />
* The demographic mix of the community<br />
population<br />
* The geographic dislribution of the<br />
population<br />
2. Kind and capacity of health care facilities;<br />
examples include:<br />
* Shonr-term, general hospital<br />
* Specialty hospitala and institutions<br />
* Nursing, personal, or domiciliary care<br />
establishments<br />
· Custodial care homes<br />
is helpful to identify asnd evaluate these aspects<br />
explicily.' ° Several generic sources of continuity<br />
include the so-called organizational and<br />
demographic superstructure and the kind and<br />
capacity of health service facilities in the arca.<br />
Both sets of factors change relatively slowly<br />
and both strongly affect demand for services.<br />
Table 2 includes examples of each.<br />
Of the problems in weighing these factors,<br />
perhaps the most difficult arise when appraising<br />
sources of change. There is a large amount<br />
of folk wisdom available on how to judge the<br />
streDgth of political and social forces. But successful<br />
measurement and precise forecasting of<br />
such forces is rarely (if ever) achieved. It is<br />
feasible to determine the general direction in<br />
wbich "trends" are going. It is quite difficult,<br />
however, to be correct about their magnitude<br />
and timing. This is complicated by the large<br />
number of decision-makers and their correspondingly<br />
largo measure of autonomy and<br />
discretion.<br />
Six Siglkt Forecasting Techniques<br />
So far, factor that contribute to demand for<br />
health ervica, ad the broader set of factors<br />
that contribute to both change and continuity<br />
in the community health care picture, have been<br />
described without reference lo how cach might
e forecast. This section descijbcs su ;aeti.<br />
techniques for dealing with each sct more systematically,<br />
and suggests the rJjour sti
Inquiry,' Voluine XIV. Septeimber 1977<br />
- 334 -<br />
E] There is very littlc thcory available about<br />
how one should forecast using historical<br />
analyses; liitlc or no formal methodology<br />
exists and few criteria for judging "good"<br />
forecasts are available.<br />
Delphiec Tecimniques<br />
Delphi is a method by which "expert opinion"<br />
is employed in systematic fashion. A wcllstructured<br />
forecasting problem is presented to<br />
a group of peoplc who are well grounded in the<br />
field or who are otherwisc "expert." Each<br />
one makes forecasts concerning specified probleats<br />
by scparately and anonymously employing<br />
specially prepared questionnaires. Results<br />
are summarizcd in a way that displays the<br />
range of responscs (usually in some quantitativc<br />
w..); these then are circulated among<br />
forecasters. The process is repeated for as<br />
many cycles as desirable in order to focus the<br />
anay of forecasts. All significant interactions<br />
~a.oel participante are in writing rather than<br />
face-to-face."<br />
Coskider a hypothetical example: An HSA<br />
situated in a rarpe. metropolitan area is concerned<br />
with p:a,.ning tt meet future demand<br />
for emergncy medical services. It has reason<br />
to think that computer-assisted diagnosis technique,<br />
currently beig discussed for emergency<br />
room use, wll strongly affect the way<br />
pl~ainb should be done. To explbr these<br />
iau, EMS experts employed Delphi at a<br />
workshop rsion of a joint physican, computer-industry<br />
symposium. They predicted<br />
tht by 1985 approximately 25 pacent of local<br />
ermen~cy room phycians will have acceas<br />
to conpute auisted diagnstic service. They<br />
employed expert opinion and data on licreas<br />
in local experimentation with the se of automated<br />
techiques in ithe medicl proeuion,<br />
toether with data on related EMS trndr. They<br />
arrived at thei forecas over a three-day per<br />
ad, employiag Delphi techdiques in tree<br />
iterations.<br />
Delphi has enjoyed caniderabe populait y<br />
in recent y~n, beinlg myd in a wide varity<br />
d f ortrctasi probln . Sone of th<br />
major reasons are sted bdow:<br />
Strenglihs Claimned:<br />
O Use of more than one "expert" (and more<br />
than one kind of :xpert) is possiblc in a<br />
well-structured w;,y.<br />
O The use of exrcrts is systematic; all confront<br />
essentiallv the same forecasting problem<br />
in the sa.ne context.<br />
O There is specific, purposeful intcraction<br />
among participants on the same problem.<br />
This tends to sharpen judgment and ideas<br />
and tends to reducc idle, unfocused speculation.<br />
O Disturbances or biases, owing to group dynamics<br />
or dominant personalitices, can be<br />
minimized.<br />
O Individual responsibility for the accuracy<br />
of forecasts (and hence possiblc inhibitions)<br />
is avoided.<br />
O The process itself can provide considerable<br />
educational benefit for those who participate<br />
through clarification of problems, issues,<br />
and goals. In addition, it can open<br />
communication lines between representatives<br />
of groups that ordinarily do not maintain<br />
contact with one another, or that have a<br />
history of inadequate communication.<br />
O The process can be especially effective in<br />
dealing with prediction problems that require<br />
intuitive judgment, and the marshaling<br />
of subconscious processes; problems, that<br />
is, which do not centrally depend upon cmpirical<br />
data and inductive processes.<br />
O The process can serve as both preparation<br />
and' follow-up for face-to-face meetings devoted<br />
to forecasting matters.<br />
O The technique can be applied in any forecasting<br />
situation wherein "expert" or otherwise<br />
desirable opinion exists, and can be<br />
reached by mailed or other questionnaires.<br />
Possible Weaknesses:<br />
O It is diffScult to design questionnaires for<br />
Delphic application that meet acceptable<br />
scientific standards for validity, appropriate<br />
selection and use of "expert opinion," reliability,<br />
mad the avoidance of error due to<br />
maUl or biasd samples of respondents. In<br />
practc, littie attention seems to have
ei, paid to these standards in conducting<br />
Delphi.' 3<br />
n '/he iterative cípnvcrgc,:: : ,i cxput upiimon<br />
may reflect increasing c :iiiotmity insicad<br />
of increasing accuracy.<br />
O "Expert" forecasts may bc more susceptible<br />
to errors arising from "scnools of thought,"<br />
conflicts, or from unanticipated developmcnis<br />
in ficlds outside the expertise in the<br />
group. The mcthod's usual total reliance<br />
on expert opinion, unleavened by other<br />
methodological checks, requires spccial<br />
caution."<br />
O The strength and accuracy of piedictions<br />
are heavily dependent upon the initial conditions<br />
specified and upon thc qualily and<br />
appropriateness of the information supplied<br />
to the participants during the iterative process.<br />
Poor information tends to produce<br />
polr results, in Delphi as elsewhere.<br />
Trend Extrapolation<br />
- 3;- --<br />
A wide range of methods fall under this heading.<br />
Each involves a review of the historical<br />
data (primarily quantitative) pertaining to<br />
sone problen: or issue. Using these data, trends<br />
are "jdermined," assumptions made, intervening<br />
vuariables are identified where pouaible, and<br />
the interaction of some combination of these<br />
facton is projected into the future as a forecasi.<br />
Regresion or time series analysis are<br />
among the mit frequently cmployed statislical<br />
Uend exrapdlation techniques.' m<br />
Two major variations of this method are<br />
common. The first projecus data that cxpress<br />
directly the phenomena being forecasted. Most<br />
bed-necd formulas used in health service forecasting<br />
are a variation on this theme. Por example,<br />
the well-known Hill-Burton formula<br />
projects bed requirements on the basis of trends<br />
in population, use-rates, and average daily<br />
censaus.'<br />
The socond common varicty is based upon<br />
data that are thought or known to be correatled<br />
with thc phenomenon being projected.<br />
This method ofien is employed when little or<br />
no dta exist for thc phenomenon one wishes to<br />
forecast. Use of demographic data as a surrogate<br />
for ith factors in column one of Table<br />
1 is a comnmon example. Or-citing the basic<br />
Forecasting Hiealh Care Services<br />
hypothetical ample used throughout this<br />
paper-an inao,, th study of EMS facilities that<br />
already have adopted computer diagnostic consulttion<br />
services might show that their usage<br />
is related in a complex way to some ten diffcrent<br />
variables. These might include such factors<br />
as physician work load, degree of medical<br />
specialization, access to and use of other consultative<br />
services, cost of the computer service,<br />
and others. Previously completed studies make<br />
it possible to predict the growth rate through<br />
1985 for these ten variables. Using these<br />
growth rates and the historical correlation between<br />
these factors and the use of computers<br />
by EMS personnel, it might be possiblc to predict<br />
that 28 percent of local EMS pcrsonnel<br />
will employ computer diagnostic consultation<br />
in 1985.<br />
Trend extrapolation methods have a number<br />
of strengths to commend them to areawidc<br />
planners. Here are some of the more important<br />
ones:<br />
Streng/lhs Claired:<br />
O Future developments often may be straightforward,<br />
predictable continuations of the<br />
present and immediate past, at least within<br />
"acceptable" error limits (e.g., population<br />
growth and mix, incidence of disease, level<br />
and distributions of income). Where this<br />
is true, trend extrapolations can be very<br />
effective at minimal cost, particularly over<br />
the short run.<br />
O These methods encourage the search for<br />
trends and continuities and for factors that<br />
cause, augment, or inhibit such trends.<br />
O Since these metheds deal with "objective"<br />
data and with matlhematical techniques, they<br />
tend to reduce (though, of course, not eliminate)<br />
the effects of analyst prejudice or<br />
bias.<br />
U The average behavior of large numbers of<br />
people is much more stable and "predictable"<br />
than that of individuals or small<br />
groups. The capacity of quantitative (particularly<br />
statistical) methods for dealing with<br />
a large volume of data is very helpful on issues<br />
involving the "trend" behavior of large<br />
populations.<br />
O Most statistical methods are based upon<br />
1¿
Inquiry,/Volume XIV, September 1977<br />
well-established statistical thceory that specifies<br />
the confidence one can have in their<br />
rcsults (c.g., the various methods for appraising<br />
the dispersion ot data about their<br />
central tendency). This tlieoretical supersltructure<br />
is very useful for drawing atten,tion<br />
to potential sources of imprecision or<br />
diffusion of focus in particular kinds of<br />
trend cxtrapolations.<br />
Possible Weaknesses:<br />
O Apparent trends in the data have no life<br />
of their own. Their continuity over time<br />
may be very tenuous. Though the temptation<br />
exista, such trends cannot be taken<br />
for granted.<br />
D No fomrn meas exists for taking "new"<br />
trends or !.-tor cmerging in thc future<br />
into account ila advance. Inded, the ch<br />
may be inhibited by the perceived "objectivity"<br />
of extrapolad techniques.<br />
O Most quantitative techniquaes require data<br />
that are quite precise and reliable if their<br />
major strengths are to be capitalized upon.<br />
Data most frequeantly available to areawide<br />
plannrs tend 1, be ol uncertain reliability<br />
and valdity.<br />
O IU thc uawc~ of the lorocuatig problcm<br />
canot be expreUed in quantitative terms<br />
Md in termo flr which the data re available<br />
on a year-to-year bast, most available<br />
techniquaes are only partially uble.<br />
Morpl o Ancyus id Rd e Trem<br />
1e ov l insat af metioda f~lli under<br />
thiese two nbica s ato mae a foroaati ng prob.<br />
hm more man= ubl by bre it into subproblem.<br />
One seeks to discen the relative<br />
imporence of each of the subprobkm and to<br />
improve prodicion accuracy by working with<br />
more cfcúively dched subproblems Specifc<br />
attention is paid to enumerating the set<br />
d *il itgificn t (fcusble) facon (alterativa)<br />
for explaining some outaome (echieving<br />
aome obioctive). Thae lctan eo altea=tives<br />
may be defined b~ally or throqb ime of inductive<br />
mathematical techniques, such multiple<br />
regreio or tbc compul#~id Aulmatic<br />
Interaction Detector (AID, pragram. The<br />
_ '?4 _<br />
ovcrall process is called morphological analysis;<br />
the graphic display of subproblems showing<br />
their interrelationships is called a relevance<br />
tree 7.<br />
Consider the following hypothetical example:<br />
An HSA was concerned with the future<br />
effect on total demand for services that will<br />
result from a rapid expansion of ambulatory<br />
care facilities. A large amount of data on both<br />
the working behavior of physicians and on<br />
factors contributing to demand for local ambulatory<br />
facilities was analyzed using the AID<br />
program. This program worked through the<br />
data, establishing "factors" through a series of<br />
dichotomous splits. These factors were chosen<br />
by the program because the dichotomy splits<br />
that were selected maximized the betweengroup<br />
variance. The graphic display of the<br />
series of these dichotomized factors represented<br />
a "picture" of all factors that would contribute<br />
to changes in demand for ambulatory care, expreased<br />
in terma of relative importance. Tlcse<br />
factors then were appraised by "experts" .ho<br />
rendered judgments about the extent to which<br />
each factor would change over the next few<br />
year. Taken together, the graphic display and<br />
expert judgment resulted in the forecast that<br />
demand for outpatient services would increase<br />
directly with an expeanion in such facilities,<br />
Lcading to a relative decline in use of key inpatient<br />
servicea.<br />
Whether graphic or quantitative, morphological<br />
analyis has not yet seen many applicatiom<br />
in the health care context. Its strengths<br />
Lrgely remain to be tested, but might include<br />
the following:<br />
Sreunguhs Claiumed:<br />
O Brosd, large-scale forecasting problems are<br />
much easiar to handie in "pieces."<br />
O Relevance trees readily show what is<br />
(thought to be) contingent upon what, thus<br />
chains of causality, potential arenas for<br />
conflicts of interes, and areas where organizational<br />
change are necessary (or are likely)<br />
can be shown more clearly.<br />
O Recombiastion of subproblems may show<br />
a varicty of ways in which changes might<br />
occur and might thus dispel possible tendencis<br />
to fall into "single possibility" ruts.
O Emphasis u.on the explicit enumeration of<br />
many possible alternative factors or solutions<br />
to each subproblem has significant<br />
heuristic value, encouraging the development<br />
of fresh perspectives.<br />
C3 Feelings for specific policies, organibational<br />
developments, or social factors that effectively<br />
enhance or slow progress toward areawide<br />
health goals, often emerge from relevance<br />
tree analysis.<br />
PoJsible Weaknesses:<br />
- 337 -<br />
O Where quantitative techniques arc no¡ used,<br />
successful analysis is dependent upon asking<br />
the "right" questions (i.e., decomposing the<br />
problem properly). Few effective guidelines<br />
cxist, particularly if the problem is ¡ldefiprd<br />
or poorly understood, as are most<br />
aceawUke health forecasting problems.<br />
O Where quantitative techniques are used,<br />
moast of the posible disadvantages described<br />
in connection with quantitative trend cxtrapolation<br />
metho~ds pply.<br />
O Few a prior quantitalive or qualitative<br />
guides cxist folr chbosing the factors that are<br />
relevant to a piven forecasting problem.<br />
O "A11 psbiltics" for a given problem may<br />
be extrmely large in number, particularly<br />
in auiwlde planninig-- many that the<br />
capacity of HISA paning staffb to evaluate<br />
them ¡ swamped.<br />
Compusrr Simulaons<br />
A conoeptual model s constructed of the major<br />
cadition and procesas of the situation to<br />
be preodicted. Thee lements are related to<br />
one anoother nla loicl and/or mathematica<br />
rlatioahips that expres, es accurately u posdbie,<br />
their "real word" interactioa within spci¡fed<br />
constraint. Employing the model and<br />
tbe ~cmputer, one can nerate time series (ie.,<br />
dchae in the value o( key varuiables from time<br />
perod to time period) that expresa the interaction<br />
of the model' elements. Assumptions,<br />
variables, processes ad the intecton among<br />
them, can be variad to simulate various hypoetial<br />
conditios or the adoption ol proposeg<br />
pdicia in to "rel" word."<br />
Consid«r the fcllowlS example: An HSA<br />
Forecasting Health Care Services<br />
collaborated with a local university over a<br />
two-year period to develop a model that expresses<br />
the interaction of demand for various<br />
levels of health care, including ambulatory,<br />
inpatient, emergency and long-term. Confronting<br />
numerous pressures to restrict new construction<br />
of inpatient beds, the HSA sought to simulate<br />
future demand for all services, assuming<br />
a policy that held the number of inpatient beds<br />
constant. The results shed light on the yearby-year<br />
increased ambulatory and long-term<br />
care capacity that would be required by this<br />
policy:<br />
Strengths Claimed:<br />
O The continuing, simultaneous interaction of<br />
an indefinitely large number of quantitative<br />
elements can be considered. This interaction<br />
can be simulated throughout an indefinitely<br />
long planning period. The only limitations<br />
are data availability, cost, and analyst<br />
imagination.<br />
O Complex interactions over substantial periods<br />
of time frequently produce results that<br />
are counter-intuitive. Given the limited<br />
ability of the human mind to trace out such<br />
interactions unaided, simulations may be<br />
the only fully effective means of projecting<br />
complex interactive situations.<br />
O The modl's conditions can be varied at<br />
will in order to test the effect that varlous<br />
hypothesized changes in the real world will<br />
have upon future developments.<br />
O Unlke neariy all oprations research and<br />
decison theory models, there is no requiremen.<br />
to limit analyiss to the achievement od<br />
a single objective. Progrs toward multiple<br />
objoctives can be projected unce the model<br />
need not be predicated upon nodons of<br />
optimality.<br />
O Both the construction of the model and its<br />
actual use are processes with imprasive<br />
heuristic value. Issues and problemns frequcndy<br />
are exposed and clarified that would<br />
not have emerged otherwise.<br />
O Tbe "tracing out" by the computer of inplicationsnialspacifid<br />
in the model i¡ ncay mimune fram<br />
analyst prejdi~e and bias.
InquiryiVolurne XIV. September 1977<br />
Possible Weaknesses:<br />
O Thc situalion to be simulated must be wcll<br />
understood (i.e., ne models elements, thcir<br />
rclevancc, and thcir interaction must correspond<br />
well with "reality") in order to<br />
develop a model whosc results arc not misleading<br />
or simply erroneous. This possible<br />
weakness is cspecially salient in areawide<br />
planning where the range of considerations<br />
is extrcmely wide and the amount of verified<br />
knowledge is typically rather narrow.<br />
O The variables employed in the model must<br />
bc measurable with considerable validity,<br />
recliability, and precision. since the mathematical<br />
manipulation involved in even<br />
fairly simple models can cpuse the error<br />
rate lo "ecxplode" in unpredictable ways.'9<br />
O Modeling a situation in a way that captures<br />
the essen- o" some dynamic situalion,<br />
without mislcadmng oversimplification or misrepresentation,<br />
is much more art than science.<br />
Few guides for constructing "good"<br />
models exist, particularly those of complex<br />
social situations.<br />
O Time seria data, upon which mist simulation<br />
modeL are based, must be treated<br />
carefully. The .nd oi summary indices<br />
that usually must be employed (e.g., "visits"<br />
or beda per unit of population) can be mis-<br />
Ieading. Even where such indiccs do a<br />
creditable job o capturing the rence of<br />
the p enon _hem they reprsent, such statistic<br />
may not readily reflect changes in<br />
qua~ly s coatralted with chan~ in numerical<br />
value. n Improvematen (or retogrtenuu<br />
) in efficiency or efectivaoes are<br />
difficult to take inato acont, a* well.<br />
O The deveupmeatl and oting cwt o<br />
a computer simulation o any real significance<br />
bi quite high. Por thbi roaen lone,<br />
simulations may be beyond the reach of<br />
any but the largest HSs for tbe immediate<br />
future.<br />
Docisioq Theory<br />
- 13 7, -<br />
This approach i repetativ d many found<br />
in the field o( operta rtesucb. It is useful<br />
in making what might be cad caditiona<br />
teoan a (i.e., predaiOm thwt i tb strategies<br />
prescribed by the techiques are adopd, the<br />
decision-maker can expect the most favorable<br />
future outcome under the conditions assumed).<br />
The basic method is lo define a series of alternatives<br />
among which a choice is lo be made,<br />
and to appraise each alternative in terms of<br />
its performance during a specified, comparable<br />
future time period. Thc consequences of adopting<br />
a given alternative frequently are traced<br />
out explicitly in the form of a decision tree,<br />
whose cnd points are expressed in numerical<br />
value payoff(s). Thc futurc environment may<br />
be expressed cither in terms of risk (i.e., the<br />
future assumcs one of several possible known<br />
states, each with a known probability of occurrence),<br />
or it can be dcalt with in terms of<br />
uncertainty (i.e., the future assumes onec of<br />
several known states, each with an unknown<br />
probability of occurrence). Once the alternatives<br />
are defined, and the range of possible<br />
interactions with the future environment is<br />
expressed in terms of possible payoffs, decision<br />
theory offers a range of criteria for<br />
choosing the best alternative.P'<br />
Suppose, for example, the HSA is considering<br />
four proposals lo expand long-term care<br />
(LTC) capacity in thc area. Each proposal<br />
differn in bed size. HSA staff studies indicate<br />
that future demand for LTC is somewhat unpredictable.<br />
Three posibilities are projected:<br />
low, medium, and high demand-each with an<br />
estimated probability of occurrence. A matrix<br />
is constructed that relates the additional capacity<br />
of each proposal to the three possible<br />
future demand levels. The HSA then makes<br />
ita decision using a variant of the maximum<br />
expected value criterion:<br />
Stengths Claimed:<br />
OGiven its emphasis upon explicitly tracing<br />
out as many possibilities as feasible, thc<br />
method encourages one to consider forecasting<br />
problems from as broad a perspective<br />
u possible, viewing the future as having<br />
multiple possibilities.<br />
3 It forces analysat and decision-maker alike<br />
to be as explicit as possible about the process<br />
by which alternatives are defined, examined,<br />
and evaluated.<br />
O It facilitatsc use and communication of expert<br />
opinion by structuring forecasting
*1<br />
1 21<br />
1<br />
«i<br />
1<br />
1<br />
1 1<br />
- 331, --<br />
Forecasting Health Care Services
Inqliry/Voluite XIV. September 1977<br />
- 340 -<br />
problems so as to take advantage of specific<br />
expertise. In particular, it helps distinguish<br />
and sort out issues of fact, conjecture, preference,<br />
strategy, probability of outcome, and<br />
value of outcome. This is very helpful for<br />
gearing available expertise lo those aspects<br />
for which it is uniquely suited (e.g., questions<br />
of fact vs. issues of stralegy vs. malters<br />
of preference).<br />
O It aids decision-makers in sorting out their<br />
own altitudes and preferences with respect<br />
to situations of risk, uncertainty, and indeterminancy<br />
(as these terms are defined by<br />
decision theorists).<br />
O it helps keep debate within decision-making<br />
groups focused upon important, objective<br />
aspects of the problem at hand by providing<br />
a 'picture" (e.g., the decision tree<br />
or table) from which to work.<br />
Possible Weaknesses:<br />
O The outcome or payoff corresponding to<br />
a givea alternative oftea is a complex bundle<br />
of conaquences not readily summarized by<br />
avaiable quantitative m ures, sch as<br />
dolian or patients treated. Where such<br />
eaures are uses, ,he risk of ovenimplificiation<br />
is substantial.<br />
O Oucome asociated s with pouibe alternativs<br />
often are highly uncenain entitea for<br />
wbhkl aoly rough estimates can be made.<br />
Tie p t prc~hn of a single-valued<br />
payoff may be higy mbkding.<br />
O Tbe dicrete, maunldpnAít alternatives<br />
Mequired in deciba thbeory dtr. may not<br />
be approprite, tbive tauaal situatioa.<br />
This a esrpecily true whbe te trnge of<br />
poaible ernati ve i actuly continuous<br />
(as contrasted wth dicrete), whre no<br />
man flor meaurina the reuts of a given<br />
alternative eicats, or where the environment<br />
a highly unctan or rapidly changing.<br />
O Moai decisiona must be made ina an organizatial<br />
contLt Such eavirames feature<br />
inter- and i-ntarltoa barpining<br />
ova obocv~ and th sbultneous pursuit<br />
of multiple, ac pme y oals.n<br />
'Tluse atn tend to pcddo aplbo<br />
of smne of t major advanta that decioa<br />
theory has to offer. Pua~duly vulnerable<br />
ure uch atrenl u t be cocept<br />
of utility maximization, uniform notions of<br />
optimality, well-defined criteria for choice,<br />
and the like.<br />
O The technique is not concerned with forecasting<br />
per se as much as it is with guiding<br />
decision making when the main dimensions<br />
of the future environment are known, or<br />
can be assumed with reasonable confidence.<br />
A Paradig for Applying Forecasting<br />
Techiqes to Factrs Influendng Future<br />
Dnemnd for Heiltb Services<br />
At this point in the discussion, it is necessary<br />
lo mention a framework within which existing<br />
forecasting techniques can be applied to advantage.<br />
Table 3 provides a first approximation<br />
of this framcwork.<br />
Each of aix major forecasting techniques<br />
discused in the preceding section is represented<br />
in the columnas of TabIe 3. Each of the major<br />
factors influencing demand is represented in<br />
the rows. The cell at the intersection of a given<br />
row and column represents the application of<br />
the column technique to the, row factor. Table<br />
3 representa a single technique applied to<br />
a single factor. In actual practice, of course,<br />
no such limitation would exist. In many cases,<br />
best results would be achieved employing two<br />
(or more) methods jointly.<br />
A representative sample of cells have been<br />
selected because of the attention that the topics<br />
they rprepsent receive in the literature. Blank<br />
cells indicate. areas where little or no research<br />
activity has taken place. As Table 3 indicates,<br />
these unexplored areas predominate over arcas<br />
where work has been done. Each cell is evaluated<br />
in summary fashion in terms of two<br />
criteria. Tiee criteria are intended to express<br />
the overall usefulness of a given technique,<br />
as applied to a given factor. The criteria:<br />
O Validity-to what extent can the technique<br />
be applied to the "essence" of the forecasting<br />
problem (as distinguished from its<br />
peripheral, ifdirectly measurable or readily<br />
undent~od, aspects)?<br />
O Precision-to what extent is the output<br />
of (he technique expressed in precise terms?<br />
Each of these ia expressed along a single<br />
dimeanion-low, moderalte, high.
Therc are ihreec basic prcessecs fin gauginig<br />
the validity and precision of a itchnique for<br />
forecasting where the technique is bised upon<br />
formal theory.<br />
: ' First, nne r:ar vcrify the log<br />
ical reasoning that led from the thci., to the<br />
prediction in question. Secoid, une can evaluate<br />
the "reasonableness" of the assumptions<br />
that underlie the porUayal of the real world<br />
situation being forecasted. And third, one can<br />
verify some of the key predictions, comparing<br />
thcm against actual events as thcy unfold.<br />
These processes can be used either singly or<br />
in combination to appraise the qualaty of the<br />
output produced by the various forecasting<br />
methods.' 4<br />
The resulis shown in Table 3 were nos arrived<br />
at through rigorous application of these<br />
proceses. Such an investigation is well beyond<br />
".. scope of this paper, requiring examination<br />
of specific applications of each technique. Inste.d,<br />
Table 3 is intended to convey an overall<br />
impreuion based upon discuwsions noted carlier.<br />
With this caveat in mind, several interim<br />
conclusions emerge:<br />
First, where possible, two or more forecastling<br />
methods should be employed in mutually<br />
rcintf:unr v:ava. In particular, historical analogie<br />
and Delphi are almost always more cffective<br />
as exploratory techniques, and/or in<br />
conjunction with one or more of the remaining<br />
t~acImqu«. No ásige method should be relied<br />
upon ecluwively.<br />
Scod dven the largo amount of unavoidable<br />
uaocrtainty in forecasting, it i important<br />
lo dc~lop atregic a*od anaytical techniques<br />
for estimating and hedging against posible<br />
error. FPoreca that provide an "optimsiicpessimistic"<br />
range rather than a point estimate,<br />
or that include discuison of pouible mitituing<br />
Iacton, serve this end.<br />
Third, as Table 3 dcates, much o the<br />
fwld o demand forecasting remaina largely<br />
unexpbrod at present. BEpecally deserving of<br />
ttention appear to be those factors that afect<br />
the phyidan's impact on demand.<br />
Fourth, dhc more sophitsicated the forecastlag<br />
tednique, the better the thuation to be<br />
forcasted mi be undersood to employ it,<br />
particularly on an ·reawide basIs. Relatively<br />
simple mb , ocused on the right ismus,<br />
can be quite effective. Sophisticaed methods<br />
Forecasting Health Care Servces<br />
vidl.,it oaiw oaf sufficient quality and quantity,<br />
or vit).,.ut the proper issue focus, may be of<br />
liírile ue.<br />
SUou. Apparent Dimetnsions of the<br />
"Zone of Feasible Forecasting"<br />
An effective way to chart some of the major<br />
'dimensions of this zone is to compare the<br />
state of the art against the objectives of areawide<br />
forecasting cited in the first section of<br />
this paper.<br />
To Provide a Picture of the Future Context<br />
Helplul to All Planners, Public and Private<br />
The ncw liSAs will be required to produce<br />
forecasts (perhaps updated annually) of the<br />
future areawide health care picture. These<br />
will be useful in carrying out their mandated<br />
functions and also can be used by all parties,<br />
public and private. The state of the art is<br />
perhaps strongest with respect to this objective.<br />
Fairly long-term forecasts, composed partly<br />
of quantitative and qualitative information, are<br />
well within the capability of existing methods.<br />
These probably can be made with "enough"<br />
assurance to provide a useful planning context<br />
for Dal interested parties.<br />
To Improve Quality and Cost Control<br />
The picture is less promising with respect to<br />
the capacity of current methods to meet this<br />
objective. Available methods can forecast dcmand<br />
for individual services with reasonable<br />
accuracy. But the state of the art reflects two<br />
major deficiencies: First, most methods to<br />
date have not been geared to forecasting demand<br />
for rwo or more services simultaneously<br />
or to forecasting demand for subspecialities<br />
within a given type of care (computer simulation<br />
being the major exception). This means<br />
the danger of ignoring the impact of changes<br />
in one service (or one subspecialty) upon the<br />
other is quite real. Second, most methods do<br />
not focus upon the appropriateness o utilization,<br />
hence the ráik of forecasting patiers of<br />
demnad that are inefficient, ineffective, or extrencly<br />
costly (and making poor docisions<br />
based upon the results) is quite high. It should
Inquiry/Volume XIV. September 1977<br />
be noted that failure to gauge "appropriateness<br />
of utilization" is not an intrinsic failure of forecasting<br />
methods; skillful and imaginative use<br />
of existing methods could overcome this deficiency,<br />
especially if supported by appropriate<br />
utilization studies.<br />
To Anticipate and Plan aor New Technologies<br />
and Methods ol Organir.tion<br />
Available forccasting methods, based upon current<br />
demand data, are poorly suited to achieving<br />
this objective. Demand is not a direct<br />
function of either technology or methods of<br />
organization. Hence, the use of current demand<br />
data (influenced to whatever degree by<br />
historical technology or methods of organization)<br />
is a poor way to achieve the objective.<br />
RIaercs aud Nots<br />
I US. Conlre, The Comprehensive Healtil Planning<br />
od Publk Hfm:ls Jer.vkts Amendtnnmu ol 1966, S<br />
OM. 9h Co.1grm. Nov. 3, 1966.<br />
2 US. Coneta. TIh Nalonal Healrh Planning and<br />
Pres.esj Derviopmwn Act ol 19?. S-2994. 93rd<br />
Can , Ia. 4, 1975.<br />
3 Se dlcuíuo of ihes objhva in¡ th Ibolowinl:<br />
M d, M. F.: "alic Comcepla nd Crucial luus<br />
in Health Plaini Ametrkn Journol of Publk<br />
HelWt. 59: 1, pp. 1697,. 1969. Colt, A. M.:<br />
*EkwIum o« Comprehenaive Health Plaing."<br />
A~rlnr louenul of Publkc Heldh. 60: 7. pp. 1194-<br />
1204. 1970. Dcky. W. 1. t al.: 'Comnpreheadve<br />
Halth PlanninaLFedcn a. Sate. Ltoal: Concepts<br />
Id imitll", W~sn Lw Revkl,. pp. 339-78,<br />
1970. Fhalb. nto t
- 343 -<br />
Forecasting Hcalth Care Servlce<br />
Sciences," 96: 639-998, Sumnaer 1967. 11 reports Zamowiz. Victor: "On Tbc Accuracy And Proper-<br />
the procedings of a symposium devoted to issues in tiae Of Short-Term Economic Foreca " The TrSAs<br />
large-scale social forecasting.<br />
Of Economies: Tire Forty-Filth Annual Report OJ<br />
9 For a discussion of how this concept has bceen de- Thie'Natioal Bureau Of Economic Restarch, 1965;<br />
veloped and used in a variety of forecasting con- also Hersch. Charles. The Discontent Explosion in<br />
text. see: Bell, D.: '"Twelve Modea of Prediction- Mental Health," American Psychologist, Vold. 23.<br />
A Preliminary Sonring. Daedalus: The Proceedings 1968. pp. 497-506. While exclusive use of ecpern<br />
of Tlhe Anmerican Academy of Arts and Sciences. 9j: opinion applied to situations in the presenr bas becn<br />
845-73. Summer 1964.<br />
largely discredited on acientific grounds. it could be<br />
10 See the entire issue of: Tite Annals of The Amrri- argued that future situation (iLe.. foecasting) are a<br />
can Academy of Poliical and Social Sclences. 399: different matter. This may be true, but the burden<br />
1-160. January 1973. devoted to the geeral topic ot proof cmns to lic with those who advocate this<br />
of: "ihe Nationsi Health: Some luues." edited by view. al present.<br />
Sylvester E. Berki and Alan W. Weston. I5<br />
For a oad discuasion of the major quantitaivd ex-<br />
II This brief description, of course, severely underatates trapolation methode in mn econometric context. see<br />
the tcope of a major methodological ficld-historiog- Fox, Karl A.. Intermediate Economic Statlstics,<br />
raphy. While not within the acope of this paper, a (New York: Wiley & Sons) 1968, especially Chap-<br />
discussion of the methodological problema in reconten 7, 8., 9 and 11.<br />
aructingl recent h;story ia worth reviewing A con- 16<br />
Report of The Committee of Consultanta, Evaluation<br />
venient survey of philodophies of history. which 01 Trhe Hill. Burton Bed Need Formula: Short-Term<br />
clearly indicates thc importance of the "t'eory of General Hospital reds, Health Care Facilitics Ser-<br />
history" employed with resard to selectivity of evi. vice Evaluation Project 71-4. Augua 1972.<br />
dence and the variability with which it is weighted in 17<br />
For an example of morphological analysis applied in<br />
evalualing · liven historical situtlion, can be found a noahealth contexi, ce Shillif. 1. E.. and Smith,<br />
in Patrick eGailiner (ed). Theorlis ol Hlloory. R. D.: "A Forecasting Method for Setting Short-<br />
(N.Y.: Free Prer), 1959, and in Dray, William H.. Rango Rescarch Objectives." Researchi Management.<br />
PhUloophy ol llitory., (Englcwood Cliffs. NJ.). 12: 24-34. March 1972. For a description of the<br />
1964. Chapter J. Sc aio Mazlihb. Bruce (cd.): AID program, see Anderon, R., et al: Automatic<br />
Tbe Rallrod and The Space Program-An4 Erplora- Inter·ction Detector Program For Analyzing<br />
blna In Nlnorkial Analogy (Cmbridge, MA: MIT Heath Survey Data." Healsit Services Research. 6:<br />
Pra)., 1965.<br />
165-U3, Sumnmer 1971. For a comparison amunong<br />
2 Por om of the best d the carly treateinta of this multi.variate stalcul tchniqua (including AID)<br />
topie, c: Helmer. Olaf, Soelal Tclsnololy. (N.Y.: from a methodoloical viewpoint, see Reinke. Wil-<br />
Bisc BDoo&). 1966. Aleo me: Vickern, Sir Oeot* liam A.: "Analysi of Multiple Sources of Varia-<br />
try. The .4r of Ietden.c. .t: A Study of Po!tcy Ma.tin: Comparion of Three Techniques." Holih<br />
ing. (L~ada: C. 1 nml ilUI), M& 1965. For a more Services Reearch. 9: 311-21, Winter 1973. For a<br />
m~m evaluatib o Delphi in the conalt of the technical discuasion of relevance trees see Fiacher,<br />
idM o wsubjective scallng, PUil, Jura: 'The Del- Manfred, Technologlcal Forecasting and Social<br />
pi Mtbod: Subiance. Contex., A Critiquc uad an Chanle 1: 4 (1970), 381-89.<br />
AaeM ?d_ Biogrpby." Soclo-conome Plinnlng 18 For a primer o the basic methods of computer<br />
S~luese. Vd. J. No. 1, Pp. 57-71. 1971. Pcr~ap simulation, ee Fomrrter, 1. W.: Principles of Sys-<br />
6 mnu ctical review of Delphi i cona te ha ¡ tem., Cambridaf, MA: MIT Pres 1967. For an<br />
Harold Son rmas' Delphl Cerlfe: Erpert Opinlon. application of simuladon in a ficid related to area<br />
FPoceuWl,. odW Grop Procet,. (LetngLaon MA: health plunnin. s Forreter. 1. W.: Urban Dy-<br />
Lamao. Boale ) 1975. An aU~ of Delphi namins (Caunbrldle, MA: MIT Pres) 1969. F:or<br />
in the iong-term care context my be found in: spcific auawide hbalt plannin application me<br />
Clark. L H.. aod Coahran. W.: "Needr o Oider YVt D. e, Dabek. L. and Intrilliaptor. M. D.:<br />
America Amnemd by Delphi Tcbnique" lJoural 'A Micro-Eccoa t[ric Model for Rcllal Health<br />
of Gerou~ogy 27(2): 275-7, Apri 1972.<br />
Plh~'" Buniu d Economi Bulletin, 24(1):<br />
13 Tbhi pouani w nca~ Delpbi b¡ parap mat 1-21, PFall 1971.<br />
frequettly overlookld in practic. A ri~ro as- 19 Thls probleam discuted effectively by Alono., W.:<br />
resmnat of Delphi agpun sadad or quetilea "Prdiica Bi With Imperfect Dau." iournal 01<br />
mire design. au embodied in the Stdard# Por Edu. The Americ~n Intliute 0f Planners. 34: 248--5,<br />
catbnal and Pjychlogkal Tesr uld Mnu U~ July 1968.<br />
pubiad by tb Amriarn Psco Arocs ti 20 Bauer, L A. (cd.). SocIal Indictors. (Cambridg,<br />
(1966), b conductd by Sackman in Chapter 3 of MA: MIT Prma) 1966.<br />
hia Delphi Crilwue: E&perl Opinlio. Feoreclng 21 Por a coin arv~y of the mior coaceptual sa<br />
And Group Procnes, (Lxinton. MA: Lcxhtalo in tbe idd o formal decliion theory. see: Ward<br />
Books) 1975. pp. 11-27.<br />
Eduarda and Amos Tvenky (ed.), Decl¡on MakitnS:<br />
14 E.uasive uwe d capef opinion to omaue uament Seltcln~ Readiint. (Middlexs. E id: P ua<br />
and to validate ites has beca valued in a number BooL), 1967. or Raifa, H.: DecLon Analydls: io-<br />
of casteMz. mli~ hbv tendtd to bow tiau, rod~ory L. csrer O Choies Under Uncerrulny<br />
even in ituatioa wberm ti problm aen farlry el (Rdend MA: Addlon Wetley) 1968. An inter-<br />
structured and thc informafion av-llaMc a sncas e~Lng appUaa~ of deciiu thcory in re oal<br />
ably complt,. aepen opiaion ia not speally d. hab Iplal appears Grinmes. d a.: Urn od<br />
lective or reliable as compered with plauidble ater. D~c Toy~ in Reioral PhnaLn" HNdalih Set.<br />
ntive mc~odr Por dudie in vrand coMtai nec vrtes RMaku,. 7: 73-78, 1974. Of particular Ibar.
Inquiry/Volumne XIV. September 1977<br />
- 344 -<br />
cst lo health planners in the project review funclion solved. For example, see Helmer, O. and Rescher,<br />
is Reutlinter..Schlomo: Techniques For Projecí Ap- N.: "On the Epistemology of the Inexact Sciences"<br />
praisl Under Uncerairnty. World Bank Staff Occa- Managenernr Sciencr, 6: 1. ¡959 pp. 25-52. A more<br />
sional Papera Number Ten (~London Johns Hopkins general vicew of the major issues is contained in<br />
Press). 1970. For a discussion ol the context into Frank. P.: Plillosophy of Science (Englewood<br />
which decision theory lits. ecc Chapter X of Kahn. Cliffs: Prentice-Hall), 1957, especially Chapters II<br />
H. and Wiener. A. J1.: The Year 2000: A Frmre. and 12. and in Ikle, F. C.: "Can Social Predictions<br />
work lor Speculation. (New York: Macmillan Co.), Be Evaluated?" Daedalus: Journal ol tie American<br />
1967.<br />
Academy of Aris and Sciences. 96(3): 733-58.<br />
22 For one of the most succinct discusiona of this or* Summer 1967.<br />
pnizationl tendency. ee Cyert. R. N., and March,<br />
J. G.:<br />
24 For<br />
A<br />
a rendering<br />
Beharioral<br />
of<br />
Tleor)o<br />
"the basic philosophical<br />
Of The Firm,<br />
problem<br />
(Englewood<br />
Cliffs: Prentice Hall), 1963, Chapter<br />
facing<br />
3. Also<br />
the forecaster'" rom the perspective of each<br />
valuable b: Thompson, J. D.. and McEwen. W. J.:<br />
of five philosophically plausible points of view, ee<br />
Orpnizational Goals Mnd Environment: Goal Set- Mitrofl. W. 1.. and Turoff. M.: *Technological<br />
ting As An Interactive Procas." Amerlcan Sociologl- Forecasting and Asaum ent-Science and/or Myral<br />
Rerlew. 23: 23-31. 1958.<br />
thology" Teclhnologkal Forecasting and Social<br />
23 The epistemology of this matter a by no meana re- Cliange. Vol. 5, 1973.
#20<br />
Jaime 1B. Henrs<br />
Rtxlnc. I.. Ro:nl'IJI<br />
- 345 -<br />
l:o man1, I¢are th..%pitll% thlo4tughttltl the<br />
Unictd Si;11e¢ have ueJ fund fíini' m gíni1N1.<br />
dtJnaltion. and othcr free monc) %i.ti,'c% I'<br />
underrtrie capilail cx:penditur¢ % foi equipmcnt.<br />
Unforiunal¢ely. ihcec fi¢l fundl. h.a..<br />
nol kepl pac*e a lh ith r.spad incrie..ec in dem;and<br />
[íor caipital epe:ndilure- As aun fllernalite<br />
t¢o ihe osuright purchaing of equipmncnl.<br />
.omeC ho,.pit;al. have itír.ted tio le .ing. Although<br />
no c.cil . ¡r.ti. .ue d.s ilahlc. ile i cs'.<br />
tinilllc'd tha;l o .w':" i:l;8llil vo rlh of1' ;1s.%'<br />
.ar Ied.cJ lo h osp'.it. in the ':nit1el Si;itel<br />
e.uch >ca¿Ir.<br />
In .in a.ttempl tos dJclcrmninc u hoilhtI'<br />
cIiI>% 1. Io Icel¢e. ilmdlinl lilttl , ;ld cL)nil oller',<br />
of .2 non-pirofit hi.pit.il. in Stluth ('arfinm.a<br />
v.e.: inter.icus. Sd. icv .fal re'.otsn% v crc o'fkied<br />
for ihcm ¢hooi-nig le¢a.ing i% ;i Ifina nc.ing<br />
.:hilí. Six of the rca;,>. nl¡hel mlt 'luqiCtl)<br />
%uggtCd . tre li.ceJ hd helow:<br />
I I h1 .a...' r 1 , e:wur d Io ha. '. v high de...e of1<br />
teChnuoloíigi c, l íh%,b leccnLe. lhco el.'t t the<br />
dildol I ti, i .e in 'ql iplni:ll Is dc.'llcd<br />
.2 .S'f hl'. 1% K,'cl oi n I .'.led cquipmin l'nt
I1':,1":" ,o1l.,' A`V. %h' h i, 19I7N<br />
I.m.ini ¡%. .'i iiI i¡nie'iJed I, 1 'pl.ill. i. li-<br />
.:1i ¡h. lI;imge of Ih, ,le 1C¢. 2<br />
True I.eaw %'erwus ('ondiional Sale<br />
Nllhi :'h · s.m.,l yI)pc. of aí;r-atngtl.nl· .,ic<br />
liriequicnll) I lr"cd lo u, Ics;c f in.aning h!<br />
l'e,,o .·;ind Ie'nc¢·J . h,,pil;al% %hutuld he a;e..eic<br />
,,f P' JiffJecni'c., in flinancing lai*raingcmcnl,.<br />
%·iie' senl ,%¢ e .¡eno oinlr;e¢t, are aclu;all ce.ndilitn.eil<br />
, Wilh : ,;lle. Iru ;tlea%e. rental pa; nl'rl ,<br />
a;re expeii'\ d fiur r¢cinhíimu-cllinl duiing th.<br />
t¢,ei mi1 shich Ihct) uoccur; on ihe 0lh¢e h;nd.<br />
msilh .i Ic.·%e.purc.ha%·c (ctinJititin;il .ile fin..c,lJ<br />
h%.. Ic.íving i
- 347 -<br />
I v,'N ti.K 1tHm.pi.l !, t1t4tlM,¡1w,;<br />
'3.4<br />
II<br />
31 Z<br />
3 4<br />
SlIMN.43iOll & .'%e'<br />
32 6<br />
I(i I'A.<br />
' .|I H) nlntlh ,,nll.,tk,<br />
k.%timnted %lm; «ar valucr tPercrniage id t I4I llh4. .J JOi.iI ! 1 . '1:. .,<br />
,'4 "i44' 4t, :
. . - , . .<br />
hlIs0, . '%'o,.t. ). .I k 197" .t , t vt AE<br />
- 348 - - /<br />
Talr 2. Beore-tax kss rilts for hospilsl equipmeit', August 197.\-.'ebruar% 1975. Primr e.,:<br />
eh -_ _3 _ __<br />
_Eqwl~ ta<br />
11.3' 11.9<br />
67.1<br />
I9l<br />
17:<br />
21..<br />
brumaetd rIhtae ,alue IPerceiuLare d roh<br />
4 1~ lase 25"&r %<br />
14 13;<br />
14 7<br />
3 .2<br />
61«l<br />
32 y<br />
19. 1<br />
191.<br />
25 4<br />
l i
Ra.fo.renem.. aid %.hs '.<br />
- 31!9 -<br />
1 ¡l¡
Mcthodologic Articles<br />
- 350 -<br />
APPLICATION <strong>OF</strong> COST-BENEFIT ANALYSIS TO THE<br />
HEALTH SERVICES AND THE SPECIAL CASE <strong>OF</strong><br />
TECHNOLOGIC INNOVATION<br />
Herbert E. Klannan<br />
As an economic technique for evaluating apecific projecta or programa it the public<br />
ctor, cost-benefit analysis is elatively new. In this paper, the theory and pra~ico of<br />
costbenefit aalysis in general ue discussed as a bass for conssdcring ita role Jn ua~e . .<br />
~tedoigy in the health §eicea A review of the literature on applications of<br />
costbenefit or cost-effectiveness analysis to the health field reveals that few complete<br />
stud~s have bcen conducted to date. It is suggestcd that an adequate analysis rtquiraes m<br />
empirical approach in which costs and benefits ae juxtaposed, and in which presuaed<br />
benefit reflect an ascertined relationship between inputs and outputs. A threefold<br />
claufition of benefita is commonly employed: direct, indiect, and intangible. Since<br />
the latter pose difficulty, cost-effectiveness analysis is often the more practicab<br />
procedur. After summanzing some problems in predicting how technologic developments<br />
me likely to affect costa and benefits, the method of cost-benefit analysu is<br />
applied to developments of hcalth systems technology in two sttings-the hospital aud<br />
automasted multiphasic screening These examples underscore the importance of solving<br />
problems of measurement and valuation of a project or program in its concrete setting.<br />
Finally, bain s to the performance of sound and systematic analysi are Usted, and the<br />
political context of decision making in the public sector is emphasized.<br />
The purpose of this paper is to discuss the application of cost-benefit analysis to the<br />
assessment of technology in the health services. With the few exceptions that are noted,<br />
the focus of this paper is on services, not research.<br />
In carrying out this task, there is no substantial body of empirical research literature to<br />
draw upon, analyze, and synthesize. Accordingly, the task will be approached in three<br />
distinct steps. First, the theory and practice Of cost-benefit analysis in general will be<br />
reviewed. Second, applications to the health field will be discussed. Third, the<br />
potentialities and limitations of cost-benefit analysis for the assessment of health systems<br />
technology will be suggested, using concrete illfstrations.<br />
THEORY AND PRACTICE <strong>OF</strong> COST-BENEFIT ANALYSIS<br />
As a formal and systematic approach to choosing among investments in public<br />
projects, cost-benefit analysis is only a generation old. It derives from the marriage of<br />
theoretical advances in the new welfare economics and the previously undernourished<br />
public expenditures branch of public finance (1). In reviews of the cost-benefit literature,<br />
few references are encountered that antedate 1958 (2-4). Most of the theoretical au well<br />
This auie ia revisin of a paper presented at the Confer~nce on T~cinology and Hhadth COa<br />
Systems in the 1980s it San Pranco in January 1972, aponsored by the Health Care System Study<br />
Sction, Natial Center for lt Svis Rerh anud Development.<br />
Inmtrntional Journl of Health Sevic~, Volunw 4, Number 2. 1974<br />
zi
; / larman<br />
u empirical research has been carned out in connection with water resources<br />
projects (5-10).<br />
Aúm and Critea of Choice<br />
- '@jl<br />
Cost-benefit analysis aima to do in the public sector what the better known<br />
supply-demand analysis does in the competitive, private sector of the economy. When<br />
market failure occurs-whethor through the absence of a market or through the existing<br />
market's behaving in undesirable ways-public intervention comes under consideration<br />
(11). Cost-benefit analysis is helpful in determining the nature and scope of such<br />
intervention.<br />
The most egregious example of lack of a market is given by the case of the pure public<br />
good. Such a good is collective, usually entails governmental action, and is characterized<br />
by a particular feature: when more of it is consumed by A, B need not consume less (12).<br />
National defense is one example frequently encountered in the literature, and the<br />
lighthouse on the shore is another. Certain aspects of basic research and the dissemination<br />
of research findings share this feature, since the acquisition of new knowledge by D does<br />
not diminish its value for C, the original investigator who developed it.<br />
In the context of cost-benefit analysis the most important cause of market failure is<br />
the presence of substantial extemal effects. Such effects are called economies if positive,<br />
and diseconomies if negative. Vaccination against a communicable disease is perhaps the<br />
most commonly cited example of benefits accruing to a third party or to the community,<br />
in addition to the benefits received by the patient and health worker, who are directly<br />
involved in the transaction'(13, p. 18). Still another example from the health field is the<br />
protection accorded to the community by hospitalizing persons with severe mental<br />
illness(14, p. 12).<br />
The goal of public policy is to adopt those projects or programs of service that yield<br />
the greatest surplus of benefits over costs. Evaluation of projects is prospective, oriented<br />
toward the future. The criterion of choice, analogous to that of maximizing profits in the<br />
market economy, is to maximize present value. Stated differently, but meaning the same,<br />
the criterion is to equalize marginal benefit and marginal cost. Strictly speaking, as<br />
Stigler (15) notes, maximizing present value is also the criterion for optimum behavior in<br />
the private sector. As Fuchs (16) pointed out, this criterion is quite different from that of<br />
attaining the maximum amount of a particular indicator of benefit.<br />
Of course, the notion of balancing benefits and costs is by no means alien to medicine.<br />
Lasagna (17) states, "Since no drug-free of toxicity-has ever been introduced that is<br />
effective for anything, those of us who are pharmacologists have learned to live<br />
reasonably comfortably with the notion of paying some sort of toxicological price for<br />
welfare."<br />
A possible source of misunderstanding about cost-benefit analysis is that benefits are<br />
usually costs presently borne that would be averted if the program in question proved to<br />
be effective. It is essential to distinguish these present and potentially avertible costs<br />
from the resource costs required to conduct that program. Since the two types of cost are<br />
not always juxtaposed, this distinction is not obvious, and the failure to draw it is not<br />
evident.<br />
There are two essential characteristics of cost-benefit analysis: breadth of scope, and<br />
length of time horizon. The objective is to include al costs and all benefits of a program,
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Application of Cost-Benefit Analysis to Health Servic~s 1<br />
no matter "to whonmsoever they accrue," over as long a period u is pertinent and<br />
practicable (3).<br />
Countir, Meaa~, g, and Valuhg Benefits and Cost<br />
When an agency wishes to undertake a project or program, it may be tempted to go far<br />
afield in counting benefits and to neglect some costs. For example, in water resources<br />
projects, certain secondary benefits may be included improperly. In vocational<br />
rehabilitation programs both savings in public assistance grants and income taxes on<br />
subsequent earnings are sometimes counted as benefits, even though neither item entails a<br />
saving in the use of resources. Both grants and taxes are transfer payments, that ai, they<br />
represent a transfer in command over resources (18, p. 47).<br />
The distinction between costs and transfers is not meant to suggest that the sole<br />
justification of public projects or programs is an increase in output or gross national<br />
product (GNP). On the contrary, there is increasing recognition that public projects or<br />
programs may carry multiple objectives, including income distribution, more jobs, and<br />
regional growth (19-22). There is no reason why, for purposes of cost-benefit analysis,<br />
earnings on a job cannot be assigned greater weight than the same amount of money<br />
received in public assistance grants (18, p. 167). What must be recognized is that such<br />
weights are judgmental, are likely to be arbitrary (at least initially), should be derived in<br />
the public arena, and, above all, must be clearly stated.<br />
Similarly, as shown by the progressive individual income tax, we seem to act on the<br />
belief in the United States that an extra dollar accruing to a low income person is worth<br />
more than an extra dollar accruing to a high income person (19). Again, assigning relative<br />
weights may help to improve analysis for public policy. There is no reason to believe,<br />
however, and no intention to claim, that agreement on such weights is imminent.<br />
On the cost side a good example of the tendency toward understatement is the neglect<br />
of compliance costs imposed on individuals and firms in calculating such costs as those of<br />
administering the individual income tax, and of Medicare for the aged. Once the<br />
installation of seat belts in automobiles is made mandatory, the temptation arises to<br />
disregard the cost of seat belts to car owners (23, 24).<br />
Counting benefits and costs involves deciding what to include and what to exclude.<br />
When an item that may be properly included can be measured, the next problem is that<br />
of valuation. The ease of valuation, indeed its possibility, depends largely on whether the<br />
item in question is traded in the market and bears a price. In that case there are many<br />
good reasons for simply adopting that price (25). When market price is deemed to be a<br />
defective measure of value, however, an attempt is made to estimate an imputed or<br />
shadow price (26). One modification of market price that is widely accepted is to set a<br />
lower value on unemployed resources; the size of this adjustment may vary not only with<br />
the state of the economy at large, but also by geographic region and by occupation (20).<br />
When an item, even an important one, lacks a market price, the tendency is to omit it<br />
from calculations. If total benefits are thereby understated, a program may be<br />
erroneously deleted. More important, perhaps, programs with a sizeable proportion of<br />
unvalued to total benefits stand to lose in competition for funda with progrnam thai have<br />
few, if any, unvalued benefits (27). Among the items most llcely to be omitted are<br />
so-called intangible benefits; such benefits are especially prominent in the health field. It<br />
is not that they can never be valued (28). Rather, one may distinguish between intangible
I Klarman<br />
- >3 -<br />
benefits that for the time being remain difficult to value and pure public goods, which are<br />
not traded on the market and therefore cannot be valued.<br />
Tbhe dilemnmas of valuation can be escaped by retreating from cost-benefit analysis to<br />
cost-effectiveness analysis. The latter i the less demanding approach, since it does not<br />
require the valuation of all benefits in terms of a common numéraire. Cost-effectiveneu<br />
analysis requires only that benefits be measured in physical terms. Once an objective or<br />
output is specified, the aim is to minimiz e the cost of attaining it. The cost data required<br />
for cost-effectiveness analysis are, however, the same as for cost-benefit analysis (29).<br />
Retreating from the valuation of benefits to measurement alone entails a substantial<br />
loss: analysis can no longer assist in setting priorities among several fields of public<br />
activity. The reason is simple. While cost-benefit analysis cuts across diverse objects of<br />
public expenditure, cost-effectiveness analysis can only help in choosing among alternate<br />
means of achieving a given, presumably desired, outcome (30). It is cost-effectiveness<br />
analysis that was incorporated as a major element in the planning, program, and<br />
budgeting (PPB) systems of the federal government. After its initial development by the<br />
Rand Corporation, PPB was introduced by the Department of Defense in 1961 and<br />
extended to other departments and agencies by Executive Order in 1965 (31, 32).<br />
Both cost-benefit analysis and cost-effectiveness analysis imply the measurement of<br />
outcomes that are associated with particular projects or programs of service. Presumably<br />
there is a link between inputs and outputs that is measurable and known. It does not<br />
matter whether bc.,avior follows a deterministic or probabilistic pattern. In the<br />
development of water resources the design of a particular project almost guarantees the<br />
emergence of certain physical outcomes-so much land will be lost to flooding, so much<br />
more land will be protected from flooding, so much land will be irrigated, etc. In national<br />
defense the outcome of a proposed course of action is much more uncertain, since other<br />
countries can take evasive and retaliatory action. In the health field, as will be shown, the<br />
presumed link between inputs and outputs is sometimes tenuous (33). Too often, the task<br />
of measurement, which necessarily precedes valuation, has been neglected.<br />
The Rate of Discount<br />
There is wide consensus in economics that a dollar is worth more today than it will be<br />
worth a year or two from now; this holds true when overall price level remains constant.<br />
As long as assets are safe, consumers are believed to have a positive time preference, that<br />
is, prefer to consume now rather than later. For producers investment may be productive<br />
through either the lapse of time, as in wine making, or the adoption of more round-about<br />
methods of production. Borrowers are therefore willing to pay interest for the use of<br />
capital, and lenders, in a capitalist economy, expect to receive interest. In a socialist<br />
economy an accounting or imputed rate of interest is employed to help allocate resources<br />
over time. The interest rate that calculates the present values of future streams of benefits<br />
and future streams of costs for public projects or programs is the well-known discount<br />
rate of cost-benefit analysis (18, p. 165).<br />
Although economists agree that a discount rate is necessary for rendering<br />
commensurate benefits accruing and costs incurred at different times, they do not agree<br />
on the size of the discount rate. Marked differences of opinion prevail for a number of<br />
reasons. One is that a diversity of interest rate structures exists in the real world, owing to<br />
capital market imperfections, differences in risk, and governmental monetary
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Application of Cost-Benefit Analysis to Health Services /<br />
pd~cies (2, 3, 34). There is controversy regarding which imperfectiona to allow for and<br />
how to allow for themn Another reason for differences of opinion, as Musgrave (35)<br />
o~ua cles, is the saitce of financing-private consumption or investment. Still another<br />
reason for differences of opinion is a value judgment: whether the proper measure of tho<br />
dLcount rate for public projects is the opportunity cost of capital in the private sector,<br />
or, to the contrary, whether it is the social rate of time preference. The private rate may<br />
be high, well above 10 per cent, particulady when allowance is made for the corporation<br />
income tax of 50 per cent (36). The social rate of time preference is usually much lower,<br />
based on a longer time horizon or greater readiness by the community acting together<br />
than by individuals to postpone gratification in favor of future generations. The social<br />
rate, which has been justified in terms of future risk and uncertainty, probability of<br />
personal survival, and the diminishing marginal utility of additional income or<br />
consumption as per capita income grows over time, is not a number that we know how to<br />
ascertain empirically (34). Accordingly, still another procedure, which combines private<br />
opportunity cost and social time preference, is also not measurable.<br />
In practice, the agencies of the federal government have employed a wide range of<br />
discount rates, usually without giving a reason (37). Nevertheless, the consequences of<br />
choosing a high or a low discount rate are clear. A low discount rate favors projects or<br />
programs with benefits accruing in the distant future. In effect, as Boulding (38) has<br />
suggested, a high interest rate favors the aged and a low one favors the middle aged. When<br />
a project or program is short-lived, with both benefits and costs concentrated in the near<br />
future, the choice of discount rate is of minor or no consequence; indeed, for a<br />
short-lived program discounting may be dispensed with. Some economists are averse to<br />
selecting a particular discount rate, on the ground that they are in no position to choose<br />
between generations (13, p. 57). The tendency is to display calculations of the present<br />
values of benefits and costs under two or more discount rates. It seems to me that such<br />
alternative calculations do not afford helpful guidance to the policy maker, unless he is<br />
advised when to employ one or the other.<br />
Even in the present state of the controversy there may be some merit to employing a<br />
single number for all public projects or for all public human investment projects. The<br />
combined method, recommended by a panel of consultants to the Bureau of the Budget<br />
in 1961 (39), and subsequently developed by Feldstein (40), can furnish an adequate<br />
rationale even though it does not yet yield a specific number. Such a number admittedly<br />
would be arbitrary, a reflection of value judgment (2). Henderson (34) reports that the<br />
French have adopted a centrally determined rate of discount of 7 per cent, to be applied<br />
to all public enterprises. This rate is higher than that encountered in many Ame~ican<br />
cost-benefit studies.<br />
APPLICATIONS <strong>OF</strong> COST-BENEFIT ANALYSIS TO THE HEALTH FIELD<br />
The health services literature contains many affirmations of the importance of<br />
cost-benefit analysis for improving the allocation of resources to and within the health<br />
field. It may prove to be a source of astonishment that relatively few complete<br />
cost-benefit studies of health programs have been carried out. Perhaps it is appropriate<br />
that fewer cost-benefit studies have been performed than advocated. Where the am is to<br />
minimize the cost of producing a given good or service, or even of constructing a hospital<br />
of specified size and with suitable appurtenances, the apparatus of cost-benefit analysis is<br />
superfluous (33). It then suffices to compare unit costs.
I Klaman<br />
Ctitena for Inchmion<br />
- 355 -<br />
The major reason for the shortness of the list of complete cost-beneflt studies is that<br />
most studies conducted to date are limited in one or more respects. First, in the 1970s.<br />
there seems to be little point to considering nonempirical analyses. Thus, today Mushkin's<br />
seminal work (41) in conceptualizing the application of cost-benefit analysis to the health<br />
feld must be excluded from consideration.<br />
A second, perhaps more critical, requirement for including a study is that both the<br />
benefits and costs of specified programs be measured and valued simultaneously, with<br />
their respective present values juxtaposed and compared. By this criterion, the majority<br />
of empirical studies so far performed in the health field are excluded, including that by<br />
Fein (42) on mental illness, by Rice (43, 44) on a number of diagnostic categories, and<br />
my own on syphilis (45) and on heart disease (46). While all of these studies attempt to<br />
measure and value the cost of a disease, thereby, in effect, measuring and valuing the total<br />
benefits of eradicating that disease, none attempts to estimate the costs of conducting<br />
programs with specified contents and aims. Although each study has made a contribution<br />
to the counting, measurement, and valuation of direct and indirect tangible benefits, and<br />
two have explored the valuation of intangible benefits, none has presented a comparison<br />
of costs and benefits under a specified set of conditions.<br />
The above two requirements-quantification and juxtaposition of costs and<br />
benefits-impress me as being incontestable. A third requirement can be defended as<br />
equally necessary: that benerits and costs reflect a known link, alluded to above, between<br />
program and outcome, i.e. between inputs and outputs. Such a link should be empirically<br />
based. Today, speculative or hypothetical relationships do not suffice (47). To apply<br />
economic valuation to hypothetical relationships between programs and outcomes is to<br />
indulge in an academic exercise, since the results of such valuation cannot transcend the<br />
quality of the underlying measurements. Such an exercise is not only idie, in that it can<br />
make no contribution to policy formulation, but it may be counterproductive if it<br />
obscures the fact that the relationships between inputs and outputs are not yet known<br />
and remain to be ascertained (14, p. 29).<br />
In an article discussing the contribution of health services to the U.S. economy,<br />
Fuchs (48) has demonstrated the importance of information concerning the efficacy of<br />
health services. The economist can indicate the types of data he requires, but he is seldom<br />
in a position to procure them by himself; he must rely on other investigators in health<br />
services research to help him to obtain them.<br />
This third requirement implies an important corollary. The size of a problem, as<br />
measured by the total costs of a disease, is not a reliable guide for policy (49, 50). Even in<br />
communicable diseases, less than eradication may be an acceptable goal. For most<br />
diagnostic conditions it is essential to know the extent to which a given program is likely<br />
to reduce the size of the problem. This point is often overlooked. It lends itself to<br />
oversight particularly when benefits and costs are not juxtaposed. In the early<br />
cost-benefit studies in the health field there may have been a further tendency for<br />
economists to attribute greater efficacy to medical care than was perhaps warranted (51).<br />
Weisbrod (13) performed the earliest of a small number of such studies and his remains<br />
one of the most systematic. He compared the benefits and costs of intervening in three<br />
diseases-cancer, polio, and tuberculosis. Drawing in a creative way on Bowen's work in<br />
deriving the demand curve for a public good (52), Weisbrod was frequently reduced to
- 356 -<br />
Application of Cost-Benefit Analysis to Health Serices /<br />
obtainng cost data and some notion of the link between inputs and outcomes from<br />
pe~onal communications with clinicians and administrators. His threefold classification<br />
of benefits-direct, indirect, and intangible-followed Mushkin and has beconm the<br />
convention.<br />
How such benefits are measured and valued, as well as an assessment of the current<br />
state of the arts, will be given below. Both accomplishments to date, and possible<br />
shortcomings in the accepted procedures will be presented.<br />
Diúect Benefits<br />
Direct benefits are that portion of averted costs currently borne which are associated<br />
with spending for health services. They represent potential tangible savings in the use of<br />
health resources. Certainly in the long run manpower not required to diagnose and treat<br />
disease and injury does become available for other uses It is reasonable to suppose that<br />
our economy, like others, has a vast variety of wants in the face of a totality of relatively<br />
scarce resources, so that freeing resources for other, desired, objectives represents a<br />
contribution to economic welfare.<br />
In the absence of a specific program of services to be evaluated, the measure of direct<br />
benefits is usually taken to be total resource costs currently incurred. The appropriateness<br />
of this measure as a basis for policy is questionable, as indicated above. Nor is it helpful<br />
to take some fraction of the total. In terms of resource use, diminishing marginal<br />
productivity is likely to set in as a program expands beyond a certain point. In terms of<br />
valuation of benefits, diminishing marginal utility is often a plausible assumption.<br />
While it is usually taken for granted that direct benefits, or the current costs of care<br />
that will be averted, can be measured with precision, this is true only when a firm<br />
produces a single good or service, such as maternity care in a special hospital. In most<br />
instances several goods or services are produced jointly. Under conditions of joint<br />
production it is possible to calculate the extra or marginal cost for each product. but not<br />
its average unit cost (10, pp. 44-45). When average unit cost figures are presented, they<br />
reflect an allocation of overhead and joint costs; and such allocation is necessarily an<br />
arbitrary accounting procedure, even where it is systematic and replicable. An alternative<br />
procedure, which is no less arbitrary, is to assign to a diagnostic category its proportion of<br />
total costs, with the proportion taken from the percentage distribution of patients or<br />
services. In the absence of facilities that produce only a single product, it might be helpful<br />
to analyze cost data for facilities with varying diagnostic compositions of patient load.<br />
However, other factors are also at play, and there is no logical solution to the problem of<br />
determining average cost under conditions of joint production of multiple outputs (18, p.<br />
166).<br />
Another complication, which affects the calculation of direct benefits and also of<br />
indirect benefits, is the simultaneous presence of two or more diseases in a patient. The<br />
presence of disease B when intervention is attempted in disease A serves to raise or lower<br />
the costs of intervention and therefore the corresponding benefits (45). The reason that<br />
indirect benefits, which represent gains in future earnings, are also affected is that the<br />
presence of diseases A and B in a patient may reduce the probability of successful<br />
outcome from the treatment of either. The effect is to overstate the benefits expected<br />
from reducing the incidence of one or the other disease (51). The magnitude of this effect<br />
is not known.
IClarman<br />
- 37 -<br />
The prevailing tendency is to take direct benefits from a single-year estimat of<br />
costs (44). Since surviours will also experience morbidity in the futuro, some medical caro<br />
costa are being neglected. Initially this procedure may have been associated with ma<br />
emphasis on single-year estimates, to the exclusion of present value estimates (50). Once<br />
the necessity of present value estimates is recognized, other explanations must be sought<br />
for this shortcut. A possible explanation is that survivors will experience only average<br />
morbidity in the future; when extra morbidity is absent, there is perhaps no need to deal<br />
with morbidity. A more plausible explanation lies in the lack of longitudinal data on the<br />
morbidity experience of defined population cohorts.<br />
The fact is that a single-year estimate reflecta the prevalence of a disease, not its<br />
incidence. It may be that the prevalence figure is sufficiently greater than the incidence<br />
figure for chronic conditions, so that it makes ample allowance for future events. Indeed,<br />
the prevalence figure in the base year is the same as the sum of the incidence figures for<br />
all survivors to this year, if certain factors remain constant, such as the size of population,<br />
death rates for the particular diagnostic group, and the incidence rate. When any of these<br />
factors follows a rising trend, however, the prevalence figure exceeds the cumulative sum<br />
of the past and present incidence figures and falls short of the sum of incidence figures<br />
expected in the future.<br />
To the extent that unit costs or prices tend to increase faster in the health services<br />
sector than in the economy at large, the value of direct benefits will also increase. In my<br />
own work 1 have incorporated an adjustment for this factor into the discount rate,<br />
deriving thereby a net discount rate (45, 46). If econoinic growth were to slow down in<br />
this country, the lag in productivity gains of the health services sector behind the<br />
economy at large would be reduced, and so would the size of this adjustment.<br />
Transportation expenses for medical care are a resource cost which is disregarded in<br />
cost-benefit analysis, although they are allowed as deductions under the individual<br />
income tax. When the physician made home calls, his travel expenses were automatically<br />
included in health service expenditures. The foremost reason for neglecting them today is,<br />
most likely, lack of reliable data. There may be the further, implicit assumption that<br />
patients' transportation costs are of a small order of magnitude.<br />
Indiect Benefits<br />
Earnings lost due to premature death or disability, which will be averted, are indirect<br />
benefits. Debility as an impairin, factor in production has not attained the prominence in<br />
empirical studies that Mushkin (41, 51) attached to it from a conceptual standpoint.<br />
Since the publication of Rice's studies (53) it is no longer necessary to estimate loss of<br />
earnings on the back of an envelope. Drawing fully on the data resources of the federal<br />
government and using unpublished tabulations almost as much as published ones,<br />
Rice (43-44) prepared her estimates in systematic fashion. She applied labor force<br />
participation rates, employment rates, and mean earnings, inclusive of fringe benefits, to<br />
the population cohort in question. For men and women separately, she derived estimates<br />
of the present values of lost earnings due to mortality under alternative discount rates and<br />
a one-year estimate of lost earnings due to disability or morbidity.<br />
Several elements of the benefit calculation that were still at issue a decade or so ago<br />
appear to be more or less settled now, some perhaps prematurely. These can be<br />
summarized as follows:
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Application of Cost-Benefit Analysis to Health Sevmic /<br />
1. Our ordinary concern is with loss in earnings, not income. The latter includue<br />
income from property.<br />
2. Consumption by survivors is no longer subtracted from gross earnings in order to<br />
artive at net earnings. Viewed prospectively, everybody is a member of society, including<br />
the patient (54).<br />
3. The value of housewives' services is recognized, despite the fact that such services<br />
are not traded in the market and are omitted from the GNP. Weisbrod (13, pp. 114-119)<br />
developed and applied a complex method for measuring the cost of a substitute<br />
housekeeper, but subsequent writers have followed Kuznets (55) in employing a simpler<br />
approach, putting the value of the services of a housewife at the level of earnings of a<br />
full-time domestic servant. To employ a single number is the more practical procedure by<br />
far. The magnitude of that number is a separate question, however. It is increasingly<br />
evident that the value given by the earnings of a domestic servant is not adequate (56).<br />
Thus, the accepted value of the housewife's contribution would increase substantially if<br />
day care centers for working women were expanded at public cost.<br />
An alternative approach is to value the housewife's contribution at the opportunity<br />
cost of her staying out of the labor force (45). Implementation of this approach is<br />
impeded by two considerations (57). First, the method is complicated, since values would<br />
vary with the individual housewife's educational attainments, type of occupation, amount<br />
of job experience, full- or part-time employment status, etc. Second, nonpecuniary<br />
factors, which certainly influence the labor force participation rates of women, are<br />
difficult to measure and may behave erratically. When total family income permits, the<br />
pecuniary opportunity cost of the wife's staying home has been known to be as low as<br />
zero or even negative.<br />
4. The employment rate has been typically taken at 96 per cent, or an overall level of<br />
4 per cent unemployment at the level of "full" employment (44). In the 1970s the<br />
magnitude of this rate is at issue. Whatever the magnitude, Mushkin's argument is<br />
accepted that the health services system should not be charged with failures by the<br />
economy to provide jobs to all who seek them (41, 58).<br />
What is often not taken into account is the tendency for persons rehabilitated after<br />
serious illness or injury to find fewer job opportunities than persons who have remained<br />
healthy and on the job. In my study of syphilis (45), 1 recognized the loss of earnings due<br />
to the "stigma" attached to this and similar diseases. When prevention is feasible, it seems<br />
appropriate to assign to it an extra weight or bonus for this reason.<br />
5. Calculations of indirect benefits rest on the implicit assumption that the life<br />
expectancies of cohorts of potential survivors are known. Usually standard life tables are<br />
employed, separately for men and women. For diseases of low frequency it seems<br />
reasonable to disregard any effect on the total death rate occasioned by the deletion of a<br />
particular cause of death. For major diseases the problem is important, although simple<br />
deletion may be incorrect. As Weisbrod (13, pp. 34-35) recognized more than a decade<br />
ago, survivors who have avoided a particular cause of death may have a higher or lower<br />
susceptibility to other, competing causes of death. I compared the effects of simply<br />
deieting heart disease as a cause of death on life expectancy and on work-life expectancy.<br />
The former was large-1 1 to 12 years-and the latter was small-less than a year (46). For<br />
a disease with heavier impact at the younger ages, the effect on work-life expectancy<br />
would be relatively larger, and correspondingly greater attention would have to be paid to<br />
the effect of competing causes of death.<br />
J
1 Klarman<br />
Intargibl Benefits<br />
- .5 -<br />
Pain, discomfort, and grief are among the costs of illness currently borne, which<br />
constitute the intangible benefits of a program of health services that averts them. The<br />
benefits accrue partly to the patients and partly to their friends, relatives, and society at<br />
large, to the extent that we. take pleasure in the happiness of others. That positive<br />
externai effects in consumption exist is indicated by personal and philanthropic gifts. to<br />
the extent that they are not subsidized by the deductibility provisions of the income<br />
tax (59). Looming even larger is the averted premature loss of human life. Since none of<br />
these effects is traded on the market, none carries a price tag. In attempting to put a value<br />
on averting them the question arises: what would one be willing to pay to avoid them?<br />
In my paper on syphilis (45), 1 estimated willingness to pay for escaping the early and<br />
late manifestations of the disease by examining expenditures incurred in connection with<br />
other diseases that met certain conditions. After consultation with clinicians 1 adopted<br />
psoriasis as the analogue for early syphilis, and terminal cancer as the analogue for its late<br />
stage. The conditions specified were that the expenditures for medical care represented<br />
principally a willingness to pay for freedom from the particular disease, since in neither<br />
case could direct or indirect tangible benefits, as defined above, be realized. To the extent<br />
that payments were made only by the patient (directly or through health insurance),<br />
willingness to pay by others was neglected and total willingness to pay was understated.<br />
Neenan (60) has estimated the consumer benefit of a community chest x-ray program<br />
for tuberculosis. With the help of some fee data indicating willingness to pay, he obtained<br />
very high estimates of value.<br />
Several years have elapsed since intangible benefits were valued. The analogous diseases<br />
approach has not been repeated; this suggests that neither the estimates themselves nor<br />
the procedures for obtaining them have been found useful. One reason is obvious: the<br />
approach is specific, calling for the development of estimates, disease by disease.<br />
A larger body of literature is devoted to the value of human itfe than to the other<br />
types of intangible health benefit. Life insurance holdings are clearly not applicable to<br />
bachelors and jury verdicts are inconsistent (13, p. 37). The implications of public policy<br />
decisions or govemmental spending are difficult to elicit in the absence of information on<br />
the alternatives that faced the decision makers (19). Moreover, such valuation may lack<br />
stability and consistency (24, pp. 133-134).<br />
Schelling(61) has proposed a different approach. He would measure the value of<br />
human life, as distinguished from livelihood, by the arnount people are willing to spend to<br />
buy a specified reduction in the statistical probability of death. Acton (24, p. 258)<br />
applied this approach, and derived an estimate of the value of human life at $28,000. This<br />
amount serves as a substitute for the net value of lost earnings and is not an additional<br />
sum.<br />
I am not sanguine about the applicability of Acton's numerical estimate to the<br />
evaluation of program alternatives. Acton was the first to criticize the defects in his<br />
estimate, including the small size of his sample, and its apparent biases. While these<br />
defects can be remedied in the future, what troubles me is the likelihood that respondents<br />
to this type of question may not grasp its meaning. Do respondents know the actual<br />
probabilities of their dying in the coming year? How is a small-e.g. 1 per cent-reduction<br />
in statistical probability perceived? How much more is a 10 per cent reduction worth<br />
than a 1 per cent reduction? Is it plausible to postulate a strictly linear relationship
- 360 -<br />
Application of Cost-Benefit Analysis to Health Services 1<br />
between increase in risk and willingness to pay to cover it? (54). Moreover, does not the<br />
value of a gain depeno somewhat on the starting point? (62). If all payments come from<br />
tbl consumer, the distribution of income must exert a sizeable influence; by how much<br />
would will igneas to pay change if the task of reducing the death rato were viewed es a<br />
collective responsibility that is fully financed from public funds?<br />
Titmusa (63) regards the value of human life as priceless and beyond valuation. Yet<br />
implicit values are being placed on human life whenever public policy decisions are made<br />
on highway design, auto safety, airport landing devices and traffic control measures.<br />
mining hazards, factory safeguards, etc. In emphasizing voluntary giving, the sense of<br />
community that the gift relationship in blood both reflects and promotes, Titmuss seems<br />
to be pointing to a large external benefits component that is neglected when life-time<br />
earnings are taken as the proxy for the value of human life. Although the concern for the<br />
altruistic motive is salubrious and appropriate, the conclusion does not follow that human<br />
life is priceless.<br />
As Mishan (54) observes, a rough measure of a precise concept is superior to a precise<br />
measure of an erroneous concept. It is agreed that the notion of the value of human life,<br />
apart from livelihood, is sound. A numerical estimate of this value would be useful in<br />
comparing the worthwhileness of alternative programs. Comparisons of programs would<br />
gain in relevance and aptness if all benefits were counted, including the saving of human<br />
life or improvements in life expectancy. This potential gain is much more likely to be<br />
realized if all benefits are entered into the model, rather than if some appear only in<br />
footnotes.<br />
I am unable to say at this time how such a number or set of numbers for the several<br />
age groups can best be derived. Certainly Schelling's questionnaire method (61) can be<br />
improved. Perhaps the implications of past or existing public policies will yield a narrower<br />
range than one expects. It is conceivable that a committee can do a better job in the<br />
realm of values than in the realm of fact. In any event, the value of human life is probably<br />
higher for identified and known individuals than for members of statistical populations. If<br />
so, incurring extraordinarily large expenditures in behalf of the former is far from<br />
conclusive evidence of irrational behavior.<br />
Weisbrod (13, p. 96) avoided dealing with the problem of valuing intangible benefits<br />
by assuming proportionality to tangible benefits. This is an unsatisfactory solution, given<br />
the'differential impacts of various diseases on life expectancy, disability, and morbidity.<br />
However, a solution to this problem was not needed when the emphasis of public<br />
expenditures analysis shifted from cost-benefit to cost-effectiveness. To repeat, in<br />
cost-effectiveness analysis outcome is expressed in physical terms, e.g. iife years gained,<br />
and the task of analysis is to discover the program that will yield the desired outcome at<br />
the lowest unit cost. In the health services it goes without saying that desired outcome<br />
incorporates a constant level of quality of care, or at least an acceptable level.<br />
Cost of Progrum<br />
The estimate of the cost of a proposed program, with which benefits are compared,<br />
poses no special difficulties. A budget is prepared in terms of the market prices of inputs,<br />
which may be adjusted by shadow prices when warranted.<br />
If programs vary in size, it is appropriate to examine the possibility that economies of<br />
scale exist (14, pp. 82-83). However, since health services are rendered in the local area,
Kllarman<br />
- 361 -<br />
thi prospects of realizing such economn ¡ies are much more limited than in the manufacture<br />
of goods. Moreover, when the size of a program increases, factor costs may rise. Finally,<br />
ua the scopo of a program approaches the size of the total population ?t risk, the extra<br />
coast of additional units of output increases when increasingly resitant grouap are<br />
encountered. Conversely, it has been suggested that in the early phases of a progran unit<br />
cast is likely to be higher than later on, since administratora learn by doing (14, p. 24)<br />
Cost-Benefit Verau Cost-Effectivenss Analys<br />
Although it is not so difficult to estimate the costs of programs, it is quite difficult to<br />
formulate the contents and expected outcomes of programs. In my judgment this has<br />
been the chief obstacle to the useful application of cost-benefit or cost-effectiveness<br />
analysis in the health field.<br />
Elsewhere 1 have listed the data required by the economist for valuing outcomes (46).<br />
A clear statement of each type of outcome is necessary. Certain events, such as death,<br />
disability, extra unemployment, and the use of health services must be entered on a<br />
calendar, beginning with the base year, and assigned a duration. The data should extend<br />
for a period as close to a person's lifetime as possible, with particular attention to the<br />
possible recurrence of illness and its exacerbation.<br />
This list of data requirements implies a degree of knowledge about the effects of<br />
health services on the health of a population that is often lacking. The obstacles to the<br />
attainment of such knowledge are many. Medicine is not an exact science, and physicians<br />
may disagree among themselves and the same physician may disagree with his own past<br />
findings. Field studies are complicated by what Morris (64) calls the iceberg<br />
phenomenon: members of the designated control group, who are presumably normal,<br />
may in fact have the disease under investigation in asymptomatic form. The possibility of<br />
inducing iatrogenic disease means that only studies performed on normal populations in<br />
the community, which are far more costly than studies of captive clinical populations,<br />
can yield valid results (65).<br />
A serious gap in existing data arises from the lack of longitudinal studies of<br />
populations. Few investigators possess the requisite patience and dedication, or<br />
experience the necessary career stability. The funding agencies, under conditions of<br />
budgetary stringency, have even shorter time horizons. Although statistical manipulation<br />
of existing cross-section and time-series data is a much cheaper and almost alwaya<br />
available approach, it may not afford an adequate substitute in many instances, especially<br />
when a high degree of correlation exists among the independent variables under scrutiny.<br />
In 1965 I reported that only one study met the longitudinal data requirementa listed<br />
above-Saslaw's study (66) on rheumatic fever. Unfortunately, the report on this study<br />
was truncated in publication. Neenan's study of chest x-rays for tuberculosis (60),<br />
conducted in 1964, concentrated on the short term, on the ground that a recovered<br />
patient suffers no impairment of earnings while early detection alone does not alter the<br />
long-term outlook. No evidence is adduced for these assumptions.<br />
Acton (24) has recently completed a cost-benefit analysis of alternative programn for<br />
reducing deaths from heart attacks. He considered five programa: an ambulance with<br />
specially trained nonphysician personnel; a mobile coronary care unit with a physician; a<br />
community triage center; a triage center combined with the ambulance; and a program to<br />
screen, monitor, and pretreat the population. The largest net benefit, whether measured
- 362 -<br />
Application of Cost-Beneflt Analysis to Health Services /<br />
by the number of live saved, or valued by the criteron of eaninm or that of wm _l~gms<br />
to pay, is given by the screening, monitoring, and pretreatment progrmnL However, tie<br />
v~lu of personal time lost in screening is neglected, and the screeing prosgrn seema to<br />
dplay grat variability in outcome. Acton's cost-benefit analysis follows his costeffectivenes<br />
analysis, in which iUves saved are not asagned a value. The screenin,<br />
monitoring and pretreatment program yields the largest number of lives saved but thi<br />
verage cost per life saved is second from the highest and the marginal cost of saving two<br />
dditional lives is 524,000 each, compared with the estimated average and marginal cost<br />
of $3,200 for saving the first 11 lives under the ambulance program (24, p. 117). Acton's<br />
work is noteworthy for the wealth of detail on the epidemiology of heart attacks.<br />
physiology, treatment, and delivery systems for treatment or prevention. This economist<br />
drew extensively on the expertise of health services speciallsts and investigaton.<br />
The report of the Gottschalk Cornmmittee to the Bureau of the Budget (BOB) (67)<br />
contains a cost-effectiveness analysis of altemative modalities for treating chronic<br />
end-stage kidney disease. The problem facing the BOB, and posed to the Committee, was<br />
to define the appropriate role of the federal government in this field. The conclusion that<br />
a substantially expanded federal role was warranted was reached on other grounds, which<br />
did not entail an economic analysis. These included: some veterans were already receiving<br />
free care in veterans administration hospitals; several foreign countries, each poorer than<br />
the United States, were committed to delivering this service to all patients; voluntary<br />
insurance plans in the U.S. were not paying for the cost of prolonged hemodialysis and<br />
their leaders saw no prospect of doing so; the patients requiring treatment largely<br />
comprised middle-aged adults; and what was still a unique life-saving measure was<br />
available for application to known individuals, persons who would otherwise die in short<br />
order. Once the recommendation was made in favor of an expanded role for the federal<br />
government and a feasible mechanism was designed to finance the care rendered to<br />
individuals, the problem that remained for economic analysis was how best to discharge<br />
this responsibility-through hemodialysis in an institution, hemodialysis in the patient's<br />
home, kidney transplantation, or some mixture of these modalities.<br />
The cost-effectiveness analysis clearly pointed to the superiority of the transplantation<br />
route, which incorporates hemodialysis both for initial and back-up support. When<br />
hemodialysis is necessary, doing it at horne is much cheaper (29). These findings<br />
influenced the Gottschalk's recommendations to the BOB that kidney transplantation be<br />
expanded as far as possible. (The best mix of modalities was not solved for because the<br />
implied assumptions of constant unit cost and constant utility of a life-year made it<br />
unnecessary.) Again, as noted with respect to Acton's study, the economic analysis drew<br />
heavily on the underlying epidemiologic, physiologic, and clinical data developed by or in<br />
behalf of the Committee.<br />
Had the Gottschalk Committee performed a cost-benefit analysis, it seems plausible to<br />
postulate that a shortage of kidneys for transplantation and the relatively greater ease<br />
with which hemodialysis facilities can expand might have yielded a higher net benefit<br />
value for dialysis, at least in the near future. However, allowance for the superior quaiity<br />
of life under transplantation would constitute a partial offset (29).<br />
Contrary to some impressions(68), the Gottschalk Committee did inquire into<br />
available prevention programs and determined that, for the foreseeable future, the<br />
number of eligible patienta with end-stage kidney disease would not change. The<br />
Committee did not inquire intra the dispersion of the distribution of life years gained.
- 363 -<br />
Thua, it did not consider whether an average gain of 10 yeara is worth the nme wben it ia<br />
the product of 10 years each gained by 100 per cent of the population at ditk, or of 20<br />
yean each gained by 50 per cent of the population, or of 40 years each gained by 25 por<br />
cont of the population. Can it be said that the marginal utility of an additional year is<br />
constant or does the principlo of diminishing manuginal utility govern?<br />
The Committee did not have to deal with two problems that might arise undor<br />
different circumstances. One is that even cost-effectiveness analysis is not so simple as it<br />
appears to be when two or more types of outcome are sought as goals. If only one<br />
outcome, such as life years gained, is preeminent, other outcomes may be neglected.<br />
Where all outcomes are important-reduced mortality, lower morbidity, and less<br />
disability-it becomes necessary once again, as under cost-benefit analysis, to arrive at<br />
common or weighted measures of outcome for alternative programs (69). Only the<br />
problem of valuing intangible benefits is escaped. However, in cost-effectiveness analysis<br />
the focus is confined to outcomes common to health services programs, and the weighting<br />
problem is serious only when the several types of outcome do not occur in the same<br />
proportions for every program. The second problem not faced by the Gottschalk<br />
Committee is the appropriate role for government to assume if expensive life-saving<br />
measures became practicable for other organs of the body. Nor did the Gottschalk<br />
Committee attempt to deal with the question of increases in patient load if the very<br />
success of the program it sponsored led to the relaxation of criteria governing patient<br />
eligibility for treatment. The quantitative effect of such relaxation may be appreciable.<br />
In the years 1966-1967, during the early spread of PPB in the federal government, a<br />
number of cost-effectiveness studies were carried out in the Department of Health,<br />
Education, .and Welfare (23, 49, 68). Although costs and benefits were calculated<br />
simultaneously, the link between the inputs and outputs of programs was measured too<br />
often by means of hypothetical numbers. Once the relationships were postulated, no<br />
effort was made to pursue the measurement problem through empirical inquiry in<br />
subsequent budgetary periods. In certain instances only expenditures chargeable to the<br />
federal budget were counted as costs, neglecting expenditures incurred by individuals and<br />
by other levels of government (23, 24).<br />
PROBLEMS IN ASSESSING HEALTH SYSTEMS TECHNOLOGY<br />
This discussion of the potentialities and hitherto modest achievements of cost-benefit<br />
analysis and cost-effectiveness analysis in the health field bears directly on the analysis of<br />
the development and spread of health systems technology. However, changes in<br />
technology bring to the fore an additional factor: a heightened degree of uncertainty<br />
concerning future benefits and costs. According to systems analysis, one appropriate<br />
response to the prospect of uncertainty is to perform a sensitivity analysis, concentrating<br />
on a few key factors or assumptions to which the measure of costs or benefits appears to<br />
be especially sensitive (34, 70). This proposition strikes me to be a formal one, awaiting<br />
empirical content.<br />
Nevertheless, within the time frame of a decade, any allowance for uncertainty due to<br />
developments in technology may be excessive. It has been suggested that the technology<br />
that will be applied in the next ten years is already known, and that the pattern of<br />
technologic diffusion is discernible (71). This view may be too sanguine, but it is not<br />
contradicted by the record of the Gottschalk Committee. By wisdom or good hluck, the
364 -<br />
Application of Cost-Benefit Analysis to Health Services ¡<br />
Comnittee's projections of survivorship of patients with transplanted kidneys and the<br />
cot of hemodialysis at home, both of which were originally supported by scanty data,<br />
hane been borne out (72).<br />
If technologic developments over the next decade are, in effect, already known to<br />
those gifted with early recognition, what can be said about prospective benefits and<br />
costa? In a plea at a health services research seminar in New York City for more research<br />
and development funds, Bennett (73) argued that the half.finished invention is the most<br />
costly product, so that technologic progress is bound to bring a lower unit cost of service,<br />
a well as improved performance.<br />
In those cases where straightforward development takes place and serious adverse<br />
ide.effects are not encountered, Bennett's view of the cost-reducing and benefitenhancing<br />
effects of technologic progress is undoubtedly correct. However, in many<br />
respects the future is shrouded in uncertainties. Such factors as the size and geographic<br />
distribution of population, value structures, and political decisions are uncertain for the<br />
future, even if technologic developments are not. Public policies are also known to create<br />
unintended and unanticipated consequences. An accepted way to deal with uncertainty is<br />
to provide for flexible operation, that is, to avoid a finely tuned operation which yields a<br />
minimum cost only for a particular scale of output. Similarly, if manpower is to be used<br />
flexibly in the future, it must be endowed with a more general education than otherwise.<br />
Thus, flexibility, whatever its cause or source, imposes a modest extra cost over a<br />
moderate range of outputs (18, pp. 105, 123-124).<br />
The Histoncal Record<br />
Rather than pursue this argument of pros and cons, I propose to examine the historical<br />
record. What have been the effects of past changes in health systems technology on costs<br />
and on benefits? A review of the literature on this subject reveals sharp differences of<br />
opinion.<br />
In a monograph on hospital expenditures sponsored by the National Center for Health<br />
Services Research and Development, Feldstein (74) attributes most of the postwar<br />
increase in hospital cost to an increase in demand, or, more precisely, to an upward shift<br />
in the demand curve. To paraphrase his argument, technical change in the absence of<br />
scientific progress may occur for two different reasons. Economic analysis has<br />
emphasized technical change in response to a shift in the relative prices of inputs (75). If<br />
wages rise faster than the prices of other inputs, for example, hospitals will economize on<br />
labor by using more disposable items, by automating laboratory procedures, etc. The<br />
effect of such substitution is to prevent costs from rising as fast as they otherwise would<br />
have.<br />
The second reason for technical change without scientific progress, which Feldstein<br />
emphasizes, is a shift in the demand for hospital care. This type of change generally yields<br />
a new product. The spreading of high-cost techniques is primarily due to rising income<br />
and increased health insurance coverage. As income increases, patients tend to raise the<br />
valuation of more costly care by relatively more than the valuation of less costly care. An<br />
increase in the proportion of the hospital bill paid by insurance will shift hospitala to<br />
more expensive technology, as the out-of-pocket price per unit of benefit is lowered.<br />
Gains in scientific knowledge, including managerial innovations, that have the<br />
potential of lowering the cost of care may actually have the opposite effect. This happens
I Klannan<br />
- 365 -<br />
again if the new scientific knowledge raises the benefits of expensive care by relativly<br />
more than the benefits of inexpensive care. In addition, if patients' real preferencs do<br />
not prevail but hospitals persist in producing services with the most expensdv techniques<br />
for which benefits are not less than cost, scientific progres cannot lower cot per patient<br />
day.<br />
In a monograph on physician expenditures, Fuchs and Kramer (76) draw a dhrp<br />
distinction between the effects of demand factors and those of technology. Their<br />
arguments concerning technology reflect an historical perspective, and may be<br />
paraphrased as follows. The late 1940s and early 1950s were marked by the introduction<br />
and widespread diffusion of many new drugs, particularly the antibiotica, which had a<br />
pronounced effect on the length and severity of infectious diseases. Since the mid-1950s,<br />
advances in medical technology have not brought about a similar improvement in the<br />
ability of physicians to improve health. Renal dialysis, cancer chemotherapy, and open<br />
heart surgery may achieve dramatic effects in particular cases, but bring about only<br />
marginal improvement in general indexes of health. Moreover, the early advances tended<br />
to be physician-saving, while the later ones were characteristically physician-using. The<br />
improvement in health resulting from the early advances was so great, that it turned the<br />
anticipated slight rise in demand for physician services into a slight decline. The reason is,<br />
according to Grossman (77), that healthier people have less objective need for physicians'<br />
services. By contrast, Fuchs and Kramer conclude that changes in demand factors had<br />
little effect on expenditures for physician services before the advent of Medicare and<br />
Medicaid in the mid- 1960s.<br />
In effect, whereas Fuchs and Kramer view technology and the conventional demand<br />
forces as being independent of one another, Feldstein holds that the effects of technology<br />
may also be exerted through a shift in demand. Both positions are stated ably and<br />
forcefully. As often happens, each raises more questions than it can answer. It would be<br />
premature, therefore, to attempt to pass judgment on the validity of the respective<br />
findings concerning the effects of technology in the postwar era.<br />
In a study focusing on the marked acceleration in the upward trends of costs and<br />
expenditures for hospital and physician services in 1966 (78), I have argued, though by<br />
no means-conclusively, that the large expansion in cost reimbursement to hospitals and<br />
the adoption of a new, previously untried method of paying physicians at reasonable and<br />
customary fees, subject to the prevailing distribution of fees in a local area, must have<br />
exerted strong effects of their own. In the case of hospitals, cost reimbursement for most<br />
patients leads to an impairment of financial self-discipline, since a dollar need only be<br />
spent in order to be gotten back. In my judgment, this proposition holds true for any<br />
institution, whether it be under voluntary nonprofit, governmental, or proprietary<br />
auspices. So far I am not persuaded by the empirical studies that have reached<br />
conclusions to the contrary (79, 80).<br />
A number of works have appeared that attempt to explain the behavior of the<br />
nonprofit hospital (81-85). They are, for the most part, far.-ranging and enlightening. One<br />
is also entertaining, positing a theory of conspicuous production, with the hospital's<br />
objective taken to be the closing of a status gap (85). None really attempts to deal with<br />
the sharp discontinuity in hospital cost and price behavior beginning in 1966.<br />
A rise in personal income may lead to greater reliance on technology for still another<br />
reason. For example, many persons are unable to stop smoking. A higher income enables<br />
them to pay more for cigarettes with a filter and reduced tar and nicotine contents.
- 566 -<br />
Application of Cost-Benefit Analysis to Health Senvice.<br />
Sbmilay, a higher income permits people to spend more on automobiles with safety<br />
dppsU, reducing the noed to exert influence on the behavior of drives. It may be mort<br />
effct~vh to operate on impersonal environmental forces than to try to chingo the<br />
bair of individuals (86).<br />
At this tim no general answer is discernible to the question of how change in halth<br />
uystan technology affect costa and benefita. It happens only once in a generation.<br />
perdapa even less frequently, that an idea such as early ambulation after surgery is born of<br />
ecessity in wartime, effects huge savings in tha use of health resoutrcs, and also exerta a<br />
positive effect on health. In most cases, the effects of technology will be mixed. Often<br />
the product is new, in the sense that a treatment is created that was not available<br />
previously and therefore could not have been demanded. The decision of whether or not<br />
to adopt a piece of technology, and the extent of its spread once adopted, depend on a<br />
number of factors, including the values of consumers, the motivations of providers, tha<br />
availability of funds, methods of provider remuneration, as weUl as the cost and efficacy<br />
of the service in question.<br />
Such a general formulation of the problem of assessing health systems technology, as<br />
provided above, affords practically no guidance to decision making. Only the concrete<br />
circumstances surrounding a project or program can indicate the special problems of<br />
measurement and valuation and the unique opportunities for solving them, what is to be<br />
emphasized in the analysis, and what may be neglected with only a moderate degree of<br />
trepidation. Accordingly, I will examine two examples in detail: hospitals and automated<br />
multiphasic screening (58).<br />
The Hospital<br />
Economists have offered essentially three views concerning capital investment in the<br />
hospital. First, hospitals invest too little capital, hence their productivity gains lag behind<br />
those of the economy at large (87). Second, hospitals invest too much, because grants and<br />
bequests accrue to them at zero price (88). Third, there is no optimum amount of<br />
investment in hospital beds, since there is no standard of appropriate hospital use (89).<br />
Conceivably, each position may have some merit to the extent that it reflects the<br />
situation in different sectors of the hospital.<br />
For simplicity I shall employ a threefold classification of hospital capital<br />
investment-patient beds, supporting housekeeping serviCes, and ancillary medical<br />
services (82). The unique problems of measurement and valuation facing the application<br />
of cost-benefit or cost-effectiveness analysis will be explored for each sector.<br />
Patient Beds The heart of the exercise in evaluating a project to expand hospital bed<br />
capacity, in my judgment, lies in one's explanation of the phenomenon of hospital use.<br />
At one pole, if the primary deterrninants of use are biologic in nature, an increase in bed<br />
supply beyond a certain point must result in additional empty beds. If hospitals are paid<br />
at stated charges, empty beds inflict a heavy financial burden on each institution (79).<br />
The reason is that fixed costs constitute two-thirds to three-quarters of total operating<br />
costsa (90). Each institution would therefore be subject to financial self-discipline in<br />
building beds, and there would be little occasion for outside intervention beyond the<br />
provision of information on the plans of other hospitals. The effect of introducing more<br />
technology might well be to increase the proportion of fixed costa to total operating<br />
costs, thereby reinforcing the efficacy of financial self-discipline.
Klarman<br />
- 367 -<br />
At the other pole, if all beds built tend to be used under conditions of prepayment, u<br />
Roemer(91,92) first suggested, there is no automatic criterion for an optinum bed<br />
supply. In the absence of evidence that low hospital use has an unfavorable effect oa<br />
health status, the appropriate public policy is to dcamp a tight lid on bed supply (79). The<br />
applUcation of more or lens technology ia the hospital is beside the point, although it does<br />
mem preferable to operate any extra beds as cheaply as possible.<br />
Patient census a a function of bed supply in the long run; combined with patient mix,<br />
it seta the requirement for nursing personnel, which may be viewed largdy au a<br />
requirement for personal services, with little or no substitution of equipment permitted.<br />
However, substitution is possible among levels of nursing personnel. The extent of actual<br />
substitution of low-paid for high-paid staff is perhaps overstated by the failure of hospital<br />
budgets to incorporate expenditures for special duty nurses.<br />
Housekeeping Services. 1 do not see any problems of sophisticated analysis in the area<br />
of supporting housekeeping services. Here the appropriate criterion for decision making is<br />
that of cost minimization. Bed sheets and towels are to be washed as cheaply as possible,<br />
for a given specification of whiteness. Patients' rooms and corridors are to be kept clean<br />
as cheaply as possible. Meals of a given quality-nutrition, calories, hot or cold-are to<br />
cost as little as possible.<br />
Once it is recognized that certain products or services need not be produced by the<br />
hospital but can be purchased from the outside, the problem is that of developing valid<br />
comparisons of unit cost. In addition, some administrators may wish to allow for certain<br />
risk factors. In the absence of competition among suppliers, the sales price may be quoted<br />
artificially low at the outset, only to be raised later. Also, in the absence of competition,<br />
purchases from the outside may increase the risk of running out of inventory.<br />
Apart from an allowance for lower risk associated with production within the hospital,<br />
estimates of internal cost of production should include only differential cost. No portion<br />
of overhead cost should be attributed, because this would continue in entirety after<br />
internal production ceased. Moreover, top management will perform the same role as<br />
coordinator, whether some goods and services are produced inside the hospital or<br />
acquired by purchase.<br />
In fact, the rise in hospital wages and gains in productivity attainable in large-scale<br />
manufacturing have led hospitals to increase the purchase and use of disposable items and<br />
ready packaged supplies. As Flagle (93) reports, gains in productivity from investment in<br />
large-scale plant have been achieved outside the health care system, which shares in them<br />
through purchase.<br />
If the objective of cost minimization is for a given level of cleanliness or nutrition, how<br />
this level is to be deterrnmined must be established. I doubt whether much would be<br />
accomplished by searching for effects on the health of patients. Rather, the criteria must<br />
be either patients' satisfaction or acceptability to management. Expressions of<br />
satisfaction are somewhat suspect, since patients are likely to be impressed by any display<br />
of interest in their opinions. A more practicable approach would be to compare<br />
alternative standards of service, none of them falling below adequacy, with the additional<br />
cost of attaining successively higher leveis.<br />
In some respects the computer partakes of a supporting housekeeping service and in<br />
other respects, when participating in diagnosis, it is akin to an ancillary medical<br />
service (94). The computer is a housekeeping service when it processes the payroll and<br />
issues bills to patients and insurance plans. As a substitute for older ways of bookkeeping
- 368 -<br />
Application of Cost-Benefit Analysis to Health Se~vlc /<br />
sud billlnS, the evaluation of compuler performance is straightforward. Docs it r~edu<br />
costs? If o, by how much?<br />
Medical Sa~ice Even when the computer helps in diagnosis the test is still coet<br />
reduction, if an older way of performing the same task is being replaced. There may be a<br />
complication, however. The cost of operating the computer falls on the hospital, whil<br />
savings in physician time accrue to the attending physician. The presence of distributional<br />
considerations suggests that the decision reached is not independent of who the decision<br />
maker is, or who exerts predominant influence on hia.<br />
Apart from the distributional considerations of who pays and who saves, evaluation of<br />
the worthwhileness of the computer in assisting in diagnosis is no different from the way<br />
another ancillary medical service, the laboratory, is evaluated. With respect to services<br />
that were rendered in the past, the test is simple. Does the new equipment save money or<br />
does it expand services for the same amount of money? In the laboratory additional and<br />
more costly equipment does replace technical personnel. A possible offset is the tendency<br />
to prescribe more services (95), although within the limits of existing capacity of<br />
equipment and staff the marginal cost of additional units of service is low. What is not<br />
known is how much good is accomplished, particularly in the absence of information on<br />
the timeliness of delivery of the reports on these services.<br />
Flagle (93) has reported economies achieved in patient surveillance due to continuity<br />
of use of the monitoring system in infusing blood. This finding strikes me as analogous to<br />
the finding in his early work (96) that a single channel is more efficient than two channels<br />
when the demand for services vanes stochastically.<br />
The intensive care unit is a more complex operation to evaluate. To the extent that it<br />
substitutes equipment for nurses it should cost less. However, the unit is also intended to<br />
save lives. The yield in life-years gained is properly subject to more sophisticated analysis.<br />
From this discussion it appears that cost-benefit or cost-effectiveness analysis is a<br />
plausible approach only if the service rendered is a new one or if the old product has<br />
changed appreciably, gaining new dimensions. When all benefits take the form of savings<br />
in health resources, that is, are direct and tangible benefits, the appropriate form of<br />
analysis is cost-benefit. When the preponderant benefits are intangible or life-saving, the<br />
dilemma is to choose between cost-benefit and cost-effectiveness analysis. On the one<br />
hand, cost-effectiveness analysis is easier to perform, since intangible benefits need only<br />
be measured but not valued. Indeed, according to Feldstein (97), even the problem of<br />
choice of discount rate is simpler in the case of cost-effectiveness analysis, with only the<br />
social time preference rate being relevant. On the other hand, to resort to<br />
cost-effectiveness analysis is to give up in advance whatever help analysis can offer in<br />
choosing among several objectives or program areas. It then becomes necessary to malke<br />
the choice among programs on other grounds, as the Gottschalk Committee did.<br />
1 am unable to discern a general resolution to this dilemma. It is certainly not evident<br />
how to establish priorities in a systematic way when cost-benefit analysis is abandoned.<br />
Perhaps the choice can still be made in a practicable way, with reasons explicitly stated,<br />
when remarkable benefits are under consideration, as in the treatment of end-stage<br />
kidney disease. When the benefits in question are modest but difficult to value, how is<br />
one to decide whether or not to adopt a particular piece of technology? To follow the<br />
lead of pace-setting organizations is almost always to say yes. Perhaps we should put trust<br />
in our ability to continue to improve the valuation of intangible bnefits in the<br />
future (28). Setting standard values on gains in life expectancy at various ages would
- 369 -<br />
seem worth exploring. However, I c-in also see increasing difficulty in the future in<br />
valuing direct tangible benefits, if fewer market prices become available for health services<br />
'n the event that provider reimbursernent shifts away from fee-for-service toward<br />
capitation and salay methods.<br />
Autonmted Multhipic Screening<br />
Often cited and discussed as an example of technologic development in the health fleld<br />
is autonmated multiphaasic health screening (98). The reports issued from the Kaiser-<br />
Permanente laboratories in Oakland and San Francisco reveal a good deal about the<br />
organization and staffing of such a service and present data on unit costs (99-103). No<br />
evaluation akin to cost-benefi¡ or cost-effectiveness analysis was attempted prior to 1973,<br />
when a preliminary cost-benefit analysis for middle-aged men was issued (104).<br />
Collen and associates(101) report that total costs for screening an individual are<br />
$21.32; which, they note, is only one-fourth or one-fifth of the cost of a periodic health<br />
examination employing more conventional modalities. The position of the authors is that<br />
this comparison will serve for the time being, pending determination of the efficacy of<br />
multiphasic health screening. The fact is that some people do.undergo a periodic health<br />
examination, whatever its efficacy may be.<br />
Garfield's position (105, 106) differs from that of Collen, in that the effectiveness of<br />
screening in arresting or curing prevíously unknown disease is beside the point. For<br />
Garfield, automated multiphasic screening has assumed a useful social function, serving as<br />
a sorting mechanism tor patlents witlh ,,epayment who would otherwise flood the health<br />
services system.<br />
I have difficulty with both positions. Collen's comparison of cost with that of the<br />
periodic health examination reminds one that the latter procedure is notoriously<br />
controversial, with the central issue revolving precisely about its effectiveness. Among<br />
physicians there appear to be true believers, persistent skeptics, and ambivalent<br />
prescribers (107-109). Furthermore, as emphastzed in the Nuffield report (110), screening<br />
implies an invitation to the patient to come and see the doctor who pronmises him a<br />
'favorable outcome. This is in contrast to the more usual visit initiated by the patient who<br />
has symptoms and seeks relief.<br />
My criticismns of Garfield's position are more serious, for his view that automated<br />
multiphasic screening shouJd be regarded as a sorting mechanism, a substitute for the<br />
rationing of services by pricc, raises a host of questions. Apparently, judging from a more<br />
recent presentation of his pGsition (1 1), much of Garfield's argument is based on an<br />
interpretation of what happened under Medicare and Medicaid. To my knowledge, the<br />
Medicare program experienced only a modest increase in the use of services and a huge,<br />
unexpected, increase in unit cost. There is no way to interpret the unanticipated rise in<br />
expenditures under Medicaid in the absence of data on trends in size of the eligible<br />
population, per capita use, and unit cost. My own view is that the increase in eligible<br />
population may have been the major factor.'<br />
Garfield (111) has hypothesized a difference in price elasticity of demand between the<br />
sick and his other three categories of patient-the well, the worried well, and the early<br />
sick. However, there have been no empirical studies of the demand for physician servica<br />
i See Klanan, H. E. Ma~j public initiative in health care. PubUc Intret 34: 106-123, 1974.
"~ ·I~t;~3?r·,,' ~ I o,,;xrvWj ', x· .. i li, 1 '<br />
- 370 -<br />
Application of Cost-Benefit Analysis to Health Setvices /<br />
in which people are so classified. From other studies it would appear that a host f(<br />
factor such as health insurance, earnings as an expression of the value of time, ae, arad<br />
the supply of providers, ae important determinants of the demand for physici a<br />
ei ices (1 2).<br />
The assertion that the supply of services for sick care is inelastic is not unique to<br />
Garfield. In the area of trends in the education of physicians, which ltakes longr and<br />
therefore responds more slowly than any other health occupation, my own readin<br />
indicates that even this system has been somewhat responsive, even while insiting that<br />
clas size in medical school must be kept small (18, p. 101), and still moro responsive<br />
after the policy decision to expand enrollment was made and implemented by funding.<br />
Whether the supply response has been sufficient to meet rising demand is, of course, a<br />
different issue.<br />
The most serious reservation I have about Garfield's position touches closely on the<br />
nature and function of cost-benefit analysis. If complete prepayment serves to create a<br />
condition of perpetual excessive demand, then some rationing or control measures are<br />
dearly indicated. Why assume, without c¿mparing alternatives, that automated<br />
multiphasic screening is the most appropriate instrumentality? It seems to me that wher<br />
the stated purposes of a program change, so should the menu of alternatives to be<br />
considered.<br />
Two reports by Collen (101, 102) on the cost of screening fil a real need. Two<br />
measures are presented-cost per test and cost per screening. Cost per test reflects only<br />
direct departmental costs, whde cost per screening incorporates an allocation of overhead<br />
expense. The article published in 1970 (102) offers a costing rule: in order to allow for all<br />
costs incurred, double the reported cost per test. The earlier article (101), which appears<br />
to present essentially the same data, suggests a blow-up of 50 per cent; I am unable to<br />
account for the difference.<br />
Since the screening process is automatic, the capital equipment is indivisible, and all<br />
procedures are schedulable, economies of scale are to be expected. The larger the scale of<br />
operation, the lower is the average unit cost. However, to achieve the lower cost, full<br />
utilization of existing facilities is essential. Accordingly, it is said to be advantageous to<br />
have available a source of stand-by patients, such as those awaiting admission to the<br />
hospital (103).<br />
Collen's second article (102) goes beyond cost per test or per screening, and reports<br />
cost per positive case. For manmmography a prevalence rate of 1.2 per cent converts the<br />
unit cost of S4.90 into a cost per positive case of $408. Since one-fifth of the women<br />
with positive mammograms have cancer of the breast, the screening cost per true positive<br />
case is 52,000. His doubling rule would raise the cost to S4,000. The cost of diagnosis for<br />
all five women and of treatment for one is still excluded.<br />
The proportion of false positives is a function not only of the accuracy of the<br />
screening test but also of the prevalence rate (113, 114). There are two reasons for aiming<br />
to keep down the number of false positives: to avoid neediess anxiety, and to prevent<br />
iatrogenic disease associated with the diagnostic process itself.<br />
The data reported to date from the Kaiser-Permanente laboratories indicate that<br />
automated multiphasic screening is both feasible and affordable. The quaetion is whether<br />
it if; worthwhile. One answer is in terms of its effects on health. The Advisory Committee<br />
on Automated Multiphasic Health Testing and Services (AMHTS) (1 15) states that much<br />
of disease uncovered by testing will be chronic or not reversible; it will not yield a saving
iKlarman<br />
- 371 -<br />
in the use of services or an improvernent in health. There seems to be Little point to using<br />
multiphasic screening if this is the case.<br />
A second answer is that of Garfield(lll), which I have criticized at length. He<br />
provides no persuasive reason for choosing this instrumentality to control the use of<br />
physician services.<br />
A third answer is possible: that automated multiphasic screening is an integral part of a<br />
package of comprehensive health services to which everybody has a right. Usually a<br />
service is aspired to by the poor because the middle and upper classes are already getting<br />
it. This is not yet the case regarding automated multiphasic screening.<br />
Clearly, a reasonable answer can only be provided through an evaluation of automated<br />
health screening for its worthwhileness. The report by the Advisory Committee(115)<br />
states, "There are elements of AMHTS that defy cost-effectiveness analysis, but which<br />
depend primarily on medical, social, and scientific objectives." If I understand the<br />
statement, I disagree with it. It may be, however, that I do not understand it. What are<br />
the medical, or social, or scientific objectives that defy measurement?<br />
Following the formulation of data requirements given in the preceding section, 1<br />
propose that data be compiled to evaluate automated multiphasic screening as follows:<br />
the volume of disease detected that was not previously known;-what could be and in fact<br />
was done about all this disease; what the outcomes in terms of health status and<br />
subsequent utilization of services were; and at how much cost, inclusive of diagnosis and<br />
treatment, the outcomes were attained (116, 117). It must be added that, as indicated by<br />
a recent paper(ll8) which compares study and control groups for such measures of<br />
outcome as work and health services utilization, CoUen's group is steadily compiling more<br />
and more of the requisite data. Still lacking is information on costs that correspond to the<br />
specified benefits.<br />
Barriers to Systematic Analysis<br />
To bring some focus to a discussion of the necessary steps ahead, I have prepared a list<br />
of barriers to the systematic and rational analysis of expenditures for health systems<br />
technology. At the same time 1 shall assess the prospects for lowering or overcoming each<br />
barrier.<br />
1. When the costs of operation mount beyond all projections, the tendency is to argue<br />
that the computer or automated laboratory, as the case may be, is not merely providing<br />
services but is performing a research function. Yet doing things we know little about does<br />
not define research. Certain features of research, such as formulation of hypotheses,<br />
design of study, and capability for statistical analysis of data, are not necessarily available<br />
wherever services are rendered. Although some replication of research is desirable, it<br />
should be intentional and need not be universal (119). It follows that sources of research<br />
funds should exercise discrimination in allocating them. If the absorption of so-called<br />
research costs by patients is precluded, this tendency to encourage pseudoresearch will be<br />
minimizae<br />
2. A tendency exists to expand the range of functions said to be performed by new<br />
equipment. Surely, data on payroll could assist management in controlling cost by<br />
department; data on billings could provide a proxy for cost data by diagnosis. The first of<br />
these applications can be evaluated according to a strict criterion: is potential cost control
- 32 -<br />
Application of Cost-Benefit Analysis to Health Services /<br />
achev~d, so that savinga are realized? The second application can be judged on it owM<br />
merits as an intermediate good: of what value is such information and to whom?<br />
3. la the health field there ia a tendency to adopt the best available and atost<br />
teohnology in every institution. This drive is promoted by the medical ethic of dolng tbhe<br />
utmost for the individual patient and reinforced by current methods of paying providera<br />
by third parties. The voluntary nonprofit form of organizing hospitals is frequently<br />
mentioned *s a factor. Still another factor is usually neglected, namely, the nature of tho<br />
physician-hospital relationship in this country. Physicians who specialize in treating<br />
patients with a given disease will not accede to its exclusion from hospital A, where thoy<br />
hold a staff appointment, unless they are granted staff privileges in hospital B, where the<br />
planning agency would like to concentrate all facilities for diagnosis and treatment. Only<br />
in part are financial interests involved; equally, or even more important, is the<br />
preservation and application of professional skills<br />
4. Economic valuation has no meaning without a firm basis in the underlying data on<br />
the link between the inputs and outputs of specific programs. It is not often that<br />
economists can develop such data. Other investigators must be persuaded and enabled to<br />
do this by investing their time and energies in longitudinal studies.<br />
5. It is discouraging to perform technical analysis, to persuade the decision makers of<br />
its usefulness, to have it adopted, and then to discover that funds for health services are<br />
cut off because total government spending is being curtailed. Adjusting aggregate demand<br />
in the economy through changes in total expenditures is bound to result in the<br />
stop-and-go operation of individual programs. This is both wasteful and frustrating, and<br />
poses a substantial threat to continuity in the provision of health services through public<br />
financing.<br />
6. Since cost-benefit or cost-effectiveness analysis is economic evaluation of public<br />
projects or programs, it must inevitably take place in a political climate. While the<br />
economic tool of cost-benefit analysis implies a delineation of goals and an articulation of<br />
values, the imperatives of the political process may call for a blurring of differences and<br />
potential conflicts, in order to facilitate the building of coalitions aimed at the<br />
accomplishment of particular ends. Schultze(31) has observed this paradox: PPB has<br />
been applied most in an area, national defense, where future uncertainty is greatest but<br />
value differences among citizens have been traditionally least; PPB is not applied much in<br />
the human resources area, where the problem of uncertainty is not so serious, but<br />
differences in values among citizens prevail, as well as a great many vested interests.<br />
Some political scientists, such as Wildavsky (120, 121), would agree with the above<br />
description and conclude that such are the facts of life. Most changes in governmental<br />
budgets are incremental anyway and do not-indeed cannot-derive from base zero (122).<br />
Within the boundaries set by defined political understandings, there are ample<br />
opportunities to improve decision making through systematic analysis. There is no reason<br />
to believe that politicians prefer to make poor decisions over good ones. In cases that are<br />
of vital importance to the body politic, many politicians, when persuaded of the right<br />
thing to do, would be willing to use up some of the credit they have accumulated and<br />
make the tough, though unpopular, choice. They cannot take such a stand on every issue,<br />
however. Therefore, the exceptionally capable practitioner of economic cost-benefit<br />
analysis must know how and when to make an allowance for the existence of a political<br />
cost-benefit calculus (120).
Kmnnan<br />
- 373 -<br />
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33. Klarman, H. E. Presnt status of coat-benefit nalyas in the health field. in J. Puble Hcdrl<br />
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34. Henderson, P. D. Investment criteria for public enterprie . Iln Pubc Ente se, edited by R.<br />
Tutvey, pp. 86-169. Penguin Modem Economies Readinga, Penguin Books, Baltimne, 1968.<br />
35. Musgrave, R. A. Cost-benefit analysis and the theory of public finance. Jounai of eo~ c<br />
Litemature 7(3): 797-806. 1969.<br />
36. Baunol, W. 1. On the discount rato for public project. In Public Expenditres aíd Pdlcy<br />
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40. Feldstein, M. S. The social time preference discount rate in cost benefit analysis. Economtc<br />
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85. Lee. M. L. A conspicuous production theory of hospital behavior. Southern Economic Jaournal<br />
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86. Rosnstock, 1. M. Why peopie use health sevices. MEibank MemL Fund Q. 44(3, part 2): 94-124,<br />
1966.<br />
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Application of Cost-Benefit Analysis to Health Servic /<br />
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90. Feldtin, P. J. An Empia~l Investigation of the Margil Cost of HospiIt S~rais C.Grduat<br />
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91. Roerer, M. 1. Bed supply and hospital utbization: A national experiment Holpilrs 35(21):<br />
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92. Shain, M., and Roemrer, iL L Hospital costs relate to the supply of beda. Mo Hosp. 92(4):<br />
71-73, 168, 1959.<br />
93. Flale, C. D. Evaluation and control of technology in health senvices In Tecdnoky andHlcath<br />
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94. Shegog, R. F. A. Reviewing some applications of computers to medicine. n Problems and<br />
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95. Ahlvin, R. C. Biochenical screening-A critique. New EngL J. Med 283(20): 1084-1086, 1970.<br />
96. Fla~e, C. D., Gabrielson, 1. W., Soriano, A., and Taylor, M. M. Analysis of Congestion in an<br />
Out-patient Clinic. Operations Research Division, The Johns Hopkins Hospital, Baltimore, 1959.<br />
97. Feldstein, M. S. Choice of technique in the public sector: A simplification. Economic Journal<br />
80(320): 985-990, 1970.<br />
98. National Academy of Engineering. A Study of Technology Assessment, pp. 96-104. Committee<br />
on Science and Astronautics, U.S. House of Representatives. U.S. Government Pinting Office,<br />
Washington, D.C., 1969.<br />
99. Collen, M. F. Statement in Subcommittee on Health of the Elderly, Special Committee a..<br />
Aging, U. S. Senate. Hearings on Detection and Prevention of Chroníc Disease Utilizing<br />
Multiphasic Health Screening Techniques, pp. 214-222. U.S. Government Printing Office,<br />
Washington, D.C., 1966.<br />
100. Collen, M. F. Periodic health examinations using an automated multitest laboratory. J.A.M.A.<br />
195(10): 830-833, 1966.<br />
101. Collen, M. F., Kidd, P. H., Feldman, R., and Cutler, J. L. Cost analysis of a multiphasic screening<br />
programu NewEngL J. Med. 280: 1043-1045, 1969.<br />
102. Collen, M. F., Feldman, R., Siegelaub, A. B., and Crawford, D. Dollar cost per positive test for<br />
automated multiphasic screening. New Engl J. Mcd 283: 459463, 1970.<br />
103. Collen, M. F. Automated multiphasic health testing: Implementation of a system. Hospitals<br />
45(5): 49-50, 56-58, 1971.<br />
104. Collen, M. F., Dales, L. G., Friedman, G. D., Flagle, C. D., Feldman, R., and Siegelaub, A.B.<br />
Multiphasic Checkup Evaluation Study: 4. Preliminary Cost-Benefit Analysis for Middle Aged<br />
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105. Garfield, S. R. The delivery of medical care. Sci. Am- 222(4): 15-23, 1970.<br />
106. Garfield, S. R. Multiphasic health testing and medical care as a right. New EngL J. Med 283(20):<br />
1087-1089, 1970.<br />
107. IngalUs, T. H., and Gordon, J. E. Periodic health' eamination, 1900-1965. Am J. Med Sci<br />
251(3): 123-140, 1966.<br />
108. Siegel, G. S. An American dilemma-The periodic .health examination. Arec. Environ. Health<br />
13(3): 292-295, 1966.<br />
109. Wade, L., Thorpe, J., Elias, T., and Bock, G. Ae periodic health exauinationa worthwhile? Ann<br />
Intern Med 56(1): 81-93, 1962.<br />
110. McKeown, T. Validation of screening proceduxea In Screening in Medical Car: Revivcing the<br />
Evidence, pp. 1-13. Oxford University Presa, London, 1968.<br />
111. Garfield, S. R. A look at the economics of medical cart. In Technology and Health Care Systems<br />
in ¡he 1980's, edited by M. F. Collen, pp. 169-175. National Center for Health Services Researi<br />
and Development, Washington, D.C., 1973.<br />
112. Feldatein, P. J. Research on the demand for health services. Milbank Mem Fund Q. 44 (3, part<br />
2): 128-162, 1966.<br />
113. Blumberg, M. S. Evaluating health screening procedurea. Operations Researc 5(3): 351-360,<br />
1957. i<br />
114. Thornet, R. R., and Remein, Q. I. Principles andProcedures in the Evaluaon ofScreeningfr<br />
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and Development, VoL 1, pp. 29, 31. U.S. Government Printing Office, Washington, D.C., 1970.<br />
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the Evidence, pp. 141-157. Oxford University Pres, London, 1968.<br />
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- 377 -<br />
i aSll a _ . b, CuaMu L. L, PFda. R., Sb,_m A. L3., a Caunp IL. Fddmm, aG D.,<br />
Dae, L. md Clbn, L F. KYF .Pemmamtu MYdtphM Sde ¡l h O * up Ei En uabi h jct:<br />
2. D~y uad COm Dioe~ lt. Snm Yo d uipe th ~ ~ P~<br />
op wmd at dt Eplmidelm Scdml A a P H h Amo~d,, Octbas 11,<br />
1971 (po~sud).<br />
119. EaLa, A., ad Re~ R TRhnolalcal *tiharu to ioci cdum Sdmc. 175: 31-38,<br />
Jum 7, 1972.<br />
120 Wiav~y. A. Ibo pdiicd ecomo~y of Bcy: CoobenfIt mul]M, md proman<br />
buptin& Púbh Adimhkbwld 2 Rep~ 26(4): 292310, 1966.<br />
12L WUdavky, A., ad Ham~P A. Com~p e sn inaental budgtlst in tho<br />
depatmut agiculmm. Admmilbtw Scda~c Q~urter 10(3): 321-346, 1965.<br />
122. ndblo, C. E De d=oin* u in¡a btxaotn mud expndituf la Puabc Fa~es: Na~e,<br />
Saomce md Utatb, editad by J. .L Bucdiman pp. 295-329. Pdn~cton Univmity Pre<br />
Pdnton, N.J., 1961.<br />
Diect reprint requerts to:<br />
Dr. Herbert E. Klanmu<br />
Professor of Economica<br />
New York University<br />
Graduate School of Public Administration<br />
4 Washington Square North<br />
New York, New York 10003<br />
MaJ serpt mAbndttd for pubilction, AprT 12, 1973
#22<br />
MAED&L C^AE<br />
Nowaenrber 1960. Vol. XVIII. No. 1<br />
- 378-<br />
Original Articles<br />
Cost-Benefit and Cost-Effectiveness Analysis<br />
in Health Care<br />
Growth and Coinpositiont of the Literature<br />
KENNETH E. WARNER, PH.D..,' AND REBFCCA C. HUTTrON, M.H.S.A., M.A.A.E.f<br />
Concern ab the etaclaing cost d health services is refitted in the rapid<br />
growth othe litehure on cod-benefit snd eod-effcctivenb M nailysis (CBA find<br />
CEA, resctfvely) in heialthd ce. A earch d dui litcrure Fr 1966-7811 produed<br />
a bibliogphy d more ithi 5l releva reerenees, gowing fom halfa<br />
dozen per year ti die beginaing d the period to dowe to 100 cach a thd mot<br />
recent 2 years. Th litture ~owth has been more rapid in mcedil than<br />
nonmedical journals and a prcference lur CEA over CBA appearn to be emrgin&<br />
Studies related to da uIs mid tre menl have uined in popularity, while<br />
the euly pominence d udies with a substantive prevention dtheme has diminirshd<br />
Consistent with the nre~asin medical focu of the literature, num-<br />
.. I L' aticles aoented towwd individual pr~tioner decision maing have<br />
apr».. mare nipidly than tho e oried towd o ni arl or soeieta decision<br />
maidns. In addition to docurrenting dthese nd this atide identifies<br />
published reviews of health care CIA/CEA ad boois and utides oteeti~nti<br />
to cenvey the prineiples r CBA/CEA to the health care community. nIe liele<br />
ncludes with specul·tion oe likeliy ner4ure trend in the iteatiure nd<br />
consideration o the quality implictions o the rpid rowth.<br />
CAÁNCERN alhimt time high and risitlg e)stN .rf<br />
health care has pronipted a wide varneil ,f,<br />
eost--ot 1 l ¡o 10 Ilt,t , ~ 1I l * J H l.tImtll,,f.t :..<br />
efl.letive and under what crecumstances,<br />
arid tíhei to *c mpare alternative interventiuns<br />
iii terrms of their ostliness. to assess<br />
their relati e c(st f-feutiiveness. The task is<br />
a monunimierital one; determiinng effectiveshess<br />
is itself immensely difflieult.'<br />
To identibf and convey the meaning of<br />
os
WAHRNER ANI) I|UTTr)N<br />
The puroses In of this article are lto descriltw safety, eínvironmental protection and cer-<br />
thi growthl and i)mpositio uíof thie health tain aspecits of individual health behavior<br />
care CBA/CEA literature, to slpl)¡a~ia¢s tli. t<br />
C(ost-lietlefit alid k íst-elecctienless<br />
.i.. sis hiave 'omlae t, r.efer to fiormal<br />
ali.l tl.iiatixe t(.se of resoed iza aniy<br />
.irnim;tlaer ¡' ;im >l)l¡.atiol.s. th e ,,il.x (ll i, ;!iir dI<br />
ii(tll(n lalt.die' al p ml)li.ati(ial s(.la i i.hs. au<br />
HlltJa ol thi't.i t
"'ol. XVIII, Nu. II1<br />
I. S ,Si 4.. l .. I.ib.111 1. l t . ."i ,.Isii.§a !l g .t .<br />
..Ts ,re' -',t 5 IIt.1LA<br />
- 380 -<br />
t II ¡Ii: l1li¡ ,illltlin, '. li chl -" ' 1 *, s et J,}. ".f' .<br />
or .*5 .d .ah- fI..ie sl. 4oJ t.. r1¡l . ",".íilh e ". ,.<br />
(:CST.BENEFIT AND) COST-EFFECTIVENESS<br />
cess of benefits over costs? Because ,il<br />
costs and benefits are measured in the<br />
same (inonetary) unit, CBA can lie<br />
employed to compare similar or widely divergent<br />
types of programs. Thus. in theory<br />
at least, CBA might be used to decide<br />
whether publie resourees should be allocated<br />
to construction of a dam or constniction<br />
of a hospital.<br />
In CEA, desirable program consequen¢es<br />
are not valued in monetary tenni,<br />
but rather arte measured in some other unit;<br />
in health care CEAs. cominon nmeasures<br />
include years of life saved and days ol' inorbidity<br />
or disahility avoided. The reasoní lor<br />
a iaoninoetariy mcasure of l prgranil tieLctiveuness<br />
is .. ither the in)p.ossil)ilit or .uudesirability<br />
of valuing imnportaiit onitel mei. e<br />
in dollars. Thus. thte " lottoiI h¡m." a<br />
CEA is not. lilke a C(BA. a nel nlt i.la'Lry<br />
value; rather. it is expretssed iii Uiaits liike<br />
"dollars per year of lilf saved." CEA ipermits<br />
eo'niparison of e.ost per unil (itf eot.leetivriness<br />
anolng conilx'ting progralla alte'rnat1;<br />
.. .1, -. 'ifd to serne the salie I)asi('<br />
purpose, biut unlikel CBA it des inot allou<br />
em)lllaristil fe I)r prgrasail, ¡lailag dliltere(tlt<br />
oDieotives. I)ca(.ise thle etli etlr'.lv', , , r<br />
eouitenilue uaí.'eieres ditl'r. Nor dI.'s it I¡. riit<br />
assessmiient of t Il. inhil, renit .rhl nl .ifa<br />
progranli: is a c .si ol'S($.5O().0r(J >t'r or lih-.<br />
sas;ved auteltal)le? ()lvioisly. tlis ilue · -<br />
tion reqjlires a sowial iind piolitivall jmdg-<br />
Ilmena:; it i ¡¡iot sililyll .h lic.il ..ner.<br />
(:BA andl (:iEA,:I lJa I 'v'tl sti.iedl ¡lr<br />
dlev-ad.(%. b)y cntrib)utions<br />
appeared in print, with the exeeption<br />
of a chapter by Grosse4 in a 1970<br />
book n.;iented toward stiidents of<br />
econoumiies and policy analysis. This chapter<br />
is parti':ularly noteworthy Icr its reiew<br />
ofí C:A/CEA applications in tll,. Departmeni<br />
of l.ahlth, Education, antd 'elll'are<br />
(HEW) during the author's tc, uure as all<br />
HEW fllicial. Grosse cun)eyed miiIlh of<br />
thi' samle lmaterial in ani article publishedl 2<br />
years later/ though agairi tie audience was<br />
o¡it heallth care p)rnt'ssioaiais. That same<br />
year. houweer. witnessed p>ulblicatioi of a<br />
h),>,k which I )h'anie one of the health care<br />
c milsi¡"íity's mniost widely read asd fre-<br />
(lueIntl cited contributions, Coxhrane's<br />
Effe¿tlrm ene*s url EI:ffirideny: Randonr Reflie<br />
icS,'i * o> Ilulthl Ser.tit'(e." lil o)lur e(StirIllntlll<br />
this short IJxx)k hadl a i)roil(aimd inpa¡lt<br />
ii tlanling the' thouuglhts olf hiealtia care<br />
prol.s.aicinalis toward issties of resource<br />
scareity and thie link ewtweeln eflicieley<br />
anlid vq'ily. It is at least possilleh that (:Kehti.me'.s<br />
I>,c>k pliared a sigilgniftiat rle iii til'<br />
ralpid grousth irn healti cvare (:BA/(:IEA<br />
wh lvla I('ganm tile -fcitoewiig yvar.<br />
I¡i !971J. Klarmlan pul)lished twu- articlehs<br />
.ia CHA . iethodlioh,el. . and al)pllicationis.<br />
()1 ' 1,s fil-' Iist a tti.n cit(led re- it.' al.Ld l ;s-<br />
( ,%-i>ii el th'athh -. care (:A/(:I'EA'. li.he<br />
,pll¢'r ;,vs tli'. firt se,1 ii .prtpll ' let al)i)¢e-11 il<br />
.1 Ilmedlí..l lOlill.icl I 'lI' h teolissin ye'air.<br />
1),IhI. ", I¡ hhsh' .,I t
WARNER AND HUTfON<br />
- 381 -<br />
observers. this Journal issue stands as a<br />
landmark in the evaluation of medical<br />
practice.<br />
Two years later, another issut ,,f the New<br />
EnglandJournal of /Medicine offered readers<br />
a discussiop of CEA methodology." a<br />
, iphisticated application of it,' and an i.n-<br />
portant, thoughtful treatbnent of the limitations<br />
ol formal analysis.?' Many health services<br />
researchers adjudge this package.<br />
1omnhined with Weinstein and Stason's<br />
b>ook on hypertension policy,? to be a<br />
smilestone in health care CBAICEA. At the<br />
end of that same year. in Deemilber 1977.<br />
the Arthur D. Littie Company euinpleted<br />
an "Iiatroduction to Cost-Bene'`t Analysis<br />
Applied ta, New Healthl TechnMlogies."`'<br />
This duocumiment, intended to assist health<br />
plaanners and otliers, was prepared under a<br />
tvimtract with the 3Bureau of Hiealth Planitling<br />
tand Heoiíir.t D'v'elO>hpilctnt ¡in tihe<br />
llealth Restaurces AdministrUtion. 1fiEW.<br />
In December 1978at the Url>ian Ilnititute<br />
(:onflfren'er .)!-te t.lllrm.<br />
F!.i i l ,. ir . m I..eml, \V.mirnll .ímd,<br />
i.,.,<br />
'<br />
)l(' i '.11 il( 1 I lJli)(Jg' ,1 (:iv.¡lk '<br />
(:1i: -\. a. i .me .mmel ld II, ;.1 .li-cl )% i(ln iii<br />
I)t,. le llti l , Im
Vol. XVll. No. 11<br />
- 382 -<br />
(:()ST-BE:NEFIT AND COST-EFFECIIVENESS<br />
Development of Health Care CBA/CEA<br />
Biblioglphy and Clasification<br />
o Refereces<br />
The sucmeeding two seetion.s present an<br />
empirical andalysis of the growth and content<br />
of the health care CBA/CEA literature.<br />
The analysis derives from counts and celassiRication<br />
of more than 500 referentes in a<br />
bibliogra'., 't uovering the period 1966<br />
through 1197. atnd including CBAs and<br />
CEAs on persoraial health sernies topíies,<br />
reviews and conimnents on such literature,<br />
asd dis.cussions ofCBA/CEA iinethodology<br />
direted spl ,'ifically to health care professionals.<br />
Excluded fromn tle t il)liography<br />
arte s'ores of CBA/CEAs on Iialth-rn-le-<br />
.'ant It ,nomiuedical suibjtcts (..g., Irafíic<br />
·%alt'D' anad toitroll o>f t'n viilta uirit';t.íI l,<br />
hlltiak,.% ald ari-<br />
*l'hs 0it (:BAi(:t:A Il
.AHNF:R AND IIl'TIoN<br />
- 383 -<br />
rare I)rolssioBml:d' introdmuction tt (CBH.:<br />
CEA, w. lilt it ai)i)>npri;ate tl, inicudr. i.<br />
articles whichl purport to relate to thi¡<br />
thelme, and not only those whitl. ChB?/<br />
(:EA exlxurtb. wultld clracterize a.. teciiirally<br />
soíund.§<br />
1',ll.hw u)ilag g comptiom ol' ihe Iiliiiogr.qalhy,<br />
w(.i lassified e achi relerenm.e aceording<br />
ti thec fi)lohing (lini, ,L~is.!:<br />
tI) Yt-ar ( 1966-1¡978)<br />
i2 T)IWm (C(:A.(:EA. g sr 'ral lnikiim,)iwl,)<br />
; l>' Il,hli s.ti( , :t'llitl.< (iiclt;r.dt juinm.ul.<br />
plirlhil. ilitenscl'.l ' ri a 14.r ¡ril oMM-<br />
itr.lthr%, *Ar Ihalth >en ic. r, n.rt s lI(.I'.<br />
*ssIsIlí*¡lli:líl j(luníl. sítl,' r><br />
'i i' li.iíl I. iHtII'tJiílj .l jrr.sílUll rl h. 11h1..l-<br />
Vo'1a. XViii., ,. 11<br />
F'i;.. I (;r,'stl ,1 lih-Jtl<br />
I.<br />
r.'.*- (:IHA'!(:I l t MrJars.<br />
ir<br />
a.<br />
tiA<br />
o<br />
z<br />
0<br />
1002<br />
90. so'<br />
80<br />
70'<br />
60'<br />
50.<br />
40'<br />
30,<br />
20'<br />
1o.<br />
total la.% alu.ys 'xv('dc eJ 88i. (See' als.<br />
Tal)h. 1.)o<br />
,aaa1iat 'l',. isa ¡s *'aXaa'a si- íl. t I tv .l . l tu all.tít.I Ia'saalt . a a sl. . tla ra ! st. al Th, W . ',<br />
msa ssa.aaaí«4.. I ,saaaaal<br />
lit'd arJ*luah. , i.l.i~,i<br />
.ll tall 1.a,sas mí.<br />
Trd<br />
M. al' adll.. I i ..,'t ía 11 4< la a a t'ra lst ls ta a' l ,l'l' NL't- 'la,<br />
taslal, asasa., t l.ia SII.ss u.Atlaat rsí,alat as fas.<br />
¡,I aasrl s. z l . w _ "E' lsl. t ali'$ f il* *I it'afais -fh as' g 'ta a .a Iu al<br />
"l.. I. ,,ith (al,' ta E'F t4 < ¡A lit¢-fdniaa' y. 1(fh tid t ith l '<br />
A,. ,tl ,,aa,,l., 4.- ldta , ,s,~ Ih a, a'l, u, EhJ.l<br />
la gt 't í- ,sai- st'la.'l .tl, ttl.t ls.g¡ - I' ,u a.. t.<br />
, 9* ,l 1ala (a t:t, dlfh :at1., , 1 . ., a m , § .a..,:,. ;,t a sta. , , a aa ,, tu -le<br />
d , ;... ,a -is 3>* ltal is ,> . ,. ,,<br />
...... a»esas.¡ Ih4. tía.' - E 'hb . a < es - *. líE. .11 F... 2t.atua Ul' h'f .r tKrtu w , gi... las A I.1 l^ti. 4,,m l .§ , st<br />
:, ." tlt.. í1 F'% lstat aasa s t . t- tsa .- ,t'.t aaat laat li.<br />
I.dl:.'1 a.ía. , ."'ta'aa''.a.aial ,o,,~,,,'f .h ,,1111i.i. a*talí... ~.~,-th as% ia..a ,,( a.- l,. ti (la. ,, l ,'s, 1 ~Jl ' ailí t.1 ",. .. .1.<br />
* al- § | .s a.! a. , , í . t . E" ¡ ' . E j t - a-1<br />
.. .|. .§ ..,1tl.l.*.. .. l.. tís H 1 4:. t .: . -,<br />
- 384 -<br />
CO~ST-BENE:FIT AND :)r-)`ETI'S6<br />
CBAs,<br />
CEAs<br />
-66 F7 68 69 70 7172 73 74 75 76 77 78<br />
YEAR
WARNER AND HUTTrU.,<br />
TABLE 1. Trenda i¡m Health Care<br />
CBA/CEA, 1966-1973 and 1974-19786<br />
66~- 1974-<br />
1973 1978<br />
I Avcge~ annual number of<br />
publictions 17.0 73.2<br />
2. Publictiorns in meditcI joumrii<br />
as of total joumal publications 40.2 62.7<br />
3 (:EA, as e odf (:EA + CBAs 42.1 53.2<br />
I. if art;icle> o0,.<br />
Preventuion 44.7 22.0<br />
D)iig"".,ul> 18.8 30.9<br />
TI'u'tl*lllt 36 5 47.2<br />
5. 'c f aritl..s with OrwellmtiiOll ol.<br />
Individual .3 I -<br />
(Ogaiiu.luizaiuu 21.3 IO.8<br />
Not'Jet) (1.04 7 3.4<br />
· All dill.. .... h rI33li('.3itit ap ' 0.05<br />
- 385 -<br />
IWO)s seei liikely to !raitotc rII,.0IiI? \ I " .' l<br />
'..ll Al/l'll It 'l i '1 " 1 . Il( r '. ""l t.,' si. l I , .%<br />
ll i,..' 's.l..,- í i . . f.f 5 .f ,'uit I, .1....,* ,,l, it,.<br />
114 Jt'IlINII~.i~ IllJ j J~ 14- . 'Il I* J,. ~t-I. t u' .'I<br />
&HIJ&llllllJ.hlr ristmJ~l .J... .JJ<br />
I *,' l .till 1 .' [l ..... , " it l' I % I.. t ' 4. . it x1 ..i.<br />
Publication Vehicek<br />
MEDICAL CARE<br />
Figure 2 plots the annual numbers of<br />
articles in medical and nonmedical journals.<br />
The purpose is to examine the proportion<br />
of the literature which has been intended<br />
primarily for a physician audience<br />
anid how this propoirtion has changed over<br />
time. While the time paths follow each<br />
other *losely, the graph shows a shift from a<br />
rough parity prior to 1973 to a clear majority<br />
of medical journal articles after 1973. In<br />
other words, the rate of growth of the iedical<br />
literature 1 -s exceeded that of tite<br />
nonmedical journal literature. particularly<br />
in receait years. This shift is statistically<br />
significant (p = 0.05). (See Table 1.)<br />
In c-ategorizing references by publication<br />
vehicle, we kept track of a subset of<br />
medical articles, nantely those published<br />
in the New Eingla.id Journwl of .Medicirie.<br />
\\'e isolated theste articles becatuse of tihe<br />
Jluiri;Il'.s ge'neral )lsitioín of leadershilp in<br />
thie ieadical literature anad because several<br />
uf' the est and uiost influential health care<br />
(:CA/C:EAs have heenu pullished in the<br />
Jtur«ul. t i is iiitresting to obserne that<br />
htbId)re 1975, tice miiii)er of CBA/CEArehlvant<br />
contrihitions in tle Journal excee<br />
(ed One only oc. t (in 1968, when two<br />
c)untril>)itionis were idenltified). TheJ,)ulrual<br />
pi>u)lishled sere.í relevalit articles ini<br />
1975 antd f;oiur or muior edth ticI. y e.a r<br />
MNii of (:BAs and CEAs<br />
Prior to the inost recelit years. the amiuital<br />
>umibMe.r ,f (:BAs genernilly exceede(d the<br />
iiuiilher ofl' CEAs. Since the tnid- 1970s th,.<br />
r(.vírst- lh.as tn'( tn . Tie ei. mix ii th.u,<br />
*."tt. i!Sc '1'.ille I.)'lis pro rLs i s., tl)pprt<br />
¡,r Wrm3tNteti,'I
Vol. XVIII. No. II<br />
FIC. 2. Dilfuslun of<br />
(:BA/CEAs by type uf<br />
>,umaJ<br />
w<br />
u.<br />
o<br />
z<br />
- 386 -<br />
s'aluing Ixneftits in CBAs. u<br />
,maniplemeuntary<br />
or altemative explanations relate to tihe<br />
appaLrent relative tonceptuai simplicity ou<br />
CEA: analysts use CEA blcauobe it is ersier<br />
for the econormic layperson-c.g., the<br />
physit'ian--to understand; also. the receilt<br />
relative growth in dtie literature in mnedi¡:al<br />
journals appears.to incliude relatively niore<br />
contributions by physicilaos who. as<br />
ectonomie Iayperso
W'AHNER AND IHUTTON<br />
- 387 -<br />
treatment, compared wíth prevention, than<br />
are nonphysician health professionals (including<br />
xboth providers and health servites<br />
researchers). Also, consistent uith ihe<br />
principal early non-health care applications<br />
of CBAICEA, early healtih care<br />
CBA/CEAs toncentrated relatively rnore<br />
oi, health care "public goods," including<br />
especially commininicable disease .ontrol.,<br />
rather than individual patient care, a gromwin!<br />
t nce ner, today. Several excellent cornmiiiiinicable<br />
disease prevenitioo studies are<br />
iliid iti thle recent medical literature, 4 , " '<br />
l,>it this ii ne of the fw . substantive areas<br />
ifl wli,). , the )(llll'¡ .of ¡>re-1974 Ilnpers<br />
aIL' all y ec
Vol. XVIII, No. 11<br />
analyses whose decision-asissting pers<br />
pective is narower dthan that of"society."<br />
Our data suggeCt iat the social perspective<br />
has dominated the literature over the<br />
entire period studied, accounting for<br />
roughly 70 per cent of all publications in<br />
both the early and more recent years.<br />
However, articles oriented toward individual<br />
(e.g., practitioner) decision making<br />
have increased most rapidly in recent<br />
years. Comparng the pre- 1974 period with<br />
the years 1974 through 1978. one observes<br />
a near doubling of the share of papers<br />
oriented toward the individual perspet'tive.<br />
This growth has come at the expense<br />
of papers with an organizational orientation.<br />
While the two categories together accnunt<br />
for fewer than 30 per cent of the<br />
literature contribuitions. the shiift is statisticaily<br />
significant. (See Table 1.)<br />
ii,. 1i t, " t f 1. '... t. h's . 'i. Iho ..<br />
i id íl , í,l . l, l,',*s<br />
- 388 -<br />
COST-BENEFIT AND COST-EFFECTIVENESS<br />
have addressed mental illness probhlnms<br />
and programs. with the same number of<br />
citations relating to dental care. Together.<br />
drug abuse and alcoholism ac.ount for a<br />
similar nUmhber of references. Renal discase<br />
has received an amount of attention<br />
(almost 20 papers) dispmportionate to its<br />
health importance but reflective of the<br />
political and economic importance associated<br />
with public funding of dialysis.<br />
The federal government's mid-1960s<br />
interest in disease conitrol programs. and in<br />
kidney discase in particular, uande this the<br />
only disease problem to liave more than<br />
one citation before 1969.<br />
Two general classes of healh problesIas<br />
have captured con)siderable attention. A<br />
ariety of commnunicable diseases have<br />
>.é-en the subject of more than two dozen<br />
papers. Since cmrmmunical)le disease and<br />
Its treatirient have distinet "public goods-"<br />
Substantive Topics and Areas of characteristics," this is a logical subject of<br />
Interest in Health Care CBA/CEA§§ CBA/CEA. and it is not twoo surprising to<br />
find that ialf of all th«ie cnimmlníicalble dis-<br />
The he-: t. r.- C(BA/CEA literatuire<br />
eaM,% Iai.¡ rs date from ti Mfire 1974. By ion-<br />
icovers a ví'as array of.liseas, irol>l)his atad.<br />
trast. tlit' Set:iiid class<br />
as<br />
of<br />
indicated<br />
pIrolblens-the<br />
iii the Ireviou. ert.ioit. all iot<br />
I)rt'si tilima ofi hrtil, tfeerts.--hias<br />
the<br />
I>)een<br />
major mendical finiatiois. Yel despit(:<br />
st.iditl nmaiach imotrt ill reetmllt<br />
the diversity.<br />
)'yars.<br />
a<br />
w¡ith<br />
fe.w sUiilecas aind tolteer.as<br />
otnl 2 of 15 ipai'rs predlatinlg 1975.<br />
acoaunt<br />
Se. e.ral<br />
for a large share f the liiteratare.<br />
hirthi deliet disease prohienis<br />
The<br />
liave<br />
single<br />
redisease<br />
e(lass whi.h has cap><br />
*cci
AAHNER AND HU'TON<br />
- 389 -<br />
Several disease problenis emferge in the<br />
guise of surgeriec intended to treat them.<br />
Each of the following surgeries is the focal<br />
point of at least one reference in the bibliography:<br />
radical cystectonmy, tonsilleetomy,<br />
choleeystectomy, herniorrhaphy,<br />
appendectomy,, synovectom. joint replacemnent<br />
and hysterectomny. In addition,<br />
there is an equal number of paper, relevant<br />
to surgery and CBAICEA, but not identifiable<br />
with a specific surgery. Many of the<br />
surgery papers were contributions to a recent<br />
hook on the subject."<br />
We classified some two dozen papers as<br />
nonspecifi screening and prevention.<br />
Sorne of these related to particular acti<br />
ities (e g., multiphasic screening). while<br />
others discussed CBA/CEA issues rmutnr<br />
generally. A few represented attenmpis to<br />
cover several separatt activities.<br />
In recent year. a grt-at ded;l ih>lsliq d<br />
a(l¡liitinaol ftíum I)apl'rs oun i.obitutiotinal der-<br />
SIIl hlillm - (cart., with th(- Ip.itient typl( niot<br />
i¡, 1977 aind 1978.<br />
Inid('amtool (' ;i -li c'eui'nt )rohlh'lems .u1(1 .1id -<br />
\'Will otl.r cfitiril)u(. t (,,,l...,ld 1..('hn<br />
,Ilgi,.' 'mn.rge ans tihe 'ulit
Vol., XVIII. No. 11<br />
lustrate another instance in which technical<br />
innovations-often, in this case, substitution<br />
of one type of personnel for<br />
another-produce outcomes which are difficult<br />
to quantify usefully. Nevertheless,<br />
analysts have made a dozen contributions<br />
on this subject.<br />
We noted previously a couple oi conspicuous<br />
absences from the literature: certain<br />
major disease problems have received<br />
very limited CBA/CEA attention, diabetes<br />
and cancer therapies serving as good<br />
examples; and CBA/CEAs specific to<br />
sophisticated capital equipment are less<br />
common than policy interest might lead<br />
one to suispect, though, again. their frequency<br />
may increase due to both growth in<br />
interest and supp-.rt of analysis.<br />
Related to dearth of equipinmetsplcific<br />
stuiies, apart from w.retning procediures<br />
relatively few diagnostic procedures<br />
hav¿e been the subject of CBA/CEA<br />
attention. A few pro'edures have received<br />
isolated dis'a.si ,- hut onily radiology lhas<br />
received :; *;. : .- alentiou. Wein.stein"<br />
has iientified the evaluati.ni of diagnostic<br />
proeedures as deserving of CBA/CEA el-<br />
- 390 -<br />
COST-BENEFIT AND COST-EFFECTIVENESS<br />
and, within the social sciences, numí.rous<br />
analyses of niedical technical change. Yet<br />
"side from implicit and tangential interest<br />
in them (e.g., as a component of hypertension<br />
management), drugs have not often<br />
concemed CBA/CEA analysts.<br />
Finally, the literature reveals very little<br />
evidence of attempts to compare the costs<br />
and benefits (effectiveness) of specific<br />
medical and nonmnedical interventions to<br />
deal with health problems. While our bialiography<br />
search focused on medical ap<br />
proaches, one might have 2nticipated identification<br />
of a few studies which cross the<br />
nmedical-nonmedical border. Yet with the<br />
exception of the early HEW efforts- ' 7 tlhe<br />
principal mechanismn for crossing that borler<br />
is the reader's location and comparison<br />
.,separate. independent studies. For botd<br />
conceptual and empirical reasons, this is<br />
mnt a highly rewarding analytical strategy.<br />
Conceivably, heightened awareness of<br />
prevention altematives will motivate formral<br />
efforts to grapple with medicali¡ionaiedical<br />
coiilaparisofis iii the filture.<br />
fLrts. ¡is¡ plel i¡s supported 1»y the growing<br />
Conclusion<br />
boJdy of literature that indiíts the inrceasing<br />
use of diagnostic tests as a Inajor source<br />
of medical (osnt inflatioi,. T'he evidente<br />
suggests that everydayt . mnaiindane ttsts are<br />
at least as significanit cwotril>utors to that,<br />
inflation as the more sophistiuated aid exspensihe<br />
tec.hnbI>golo es.u yet the fomner<br />
tiave recreived í rry littlh CBA/CEA attention..<br />
Agaira. i)rol)>lhis f mita.tingiK asid<br />
vahlmiusg tilh (1t(teollt-% i >diaglultstit Ip)r< ('dures<br />
st.ied ¡i¡ the w ía.' r)fr.ath app)lication<br />
'<br />
of1 (BA./(:EA. 4,"<br />
liti (,1>llBgtlias ec(tioian. A í (. .)t* t ) otfi er<br />
ar,.. 1s wJ m.h %í.í¡ f tnle. rrE1í.I)t ,'#te- ¡ . th, e<br />
Ite rat.írta . I r it 14- l-st .\' ral ih'.,.it.-N.<br />
Reilevtking ec>ncern with the high ard rising<br />
costs (of personal health senrices. the<br />
health care CBA/CEA literature has grown<br />
* rapidlly in recent years. The social miliieu<br />
seems likely to encourage sustained interest<br />
in controlling the costs ofclare; with that<br />
ninterest should c)iyie continuing growth in<br />
analysts' efforts to gripple with issues of<br />
List effc'tiveness.<br />
lThe relative growth in medical journals'<br />
share of the literatura reflects increasing<br />
professioiUal concetrn abut the spiraling<br />
.ustNs of health snrvices: medical professioniAs<br />
are exprt u.iiig the.ir interest in the<br />
IS3m-; alld nlnonmedical analysts are exhihit-<br />
, illIL g y.O , .ll( si'lt'lltifhI<br />
fr, l tlh l i1 iii l t iit'l' ll'- .a11i¡ (h.lí.íhí .!it .alt're.(d<br />
. ,1. s )r.u'tlt' . d.i ()11tt'l)111-%. fi ,iJ lh-alth<br />
(ir.i- I)rttgs liit ( Ix.es" thd. oh i"Is . (lt,,- l- t<br />
dr.,;., otii I)i,'l;rsm l. .i. íaád 1 , da, . l tI¡i u.'.<br />
ng a d eu'il' tI, wo(rk with physiciaris to ai;-<br />
'% Irt ( gi(. vttrtit l i health care<br />
i.AI/(:EA% iii ti>.* medical literature has<br />
}l.sl a litIllilxi'I of railnficathinas: stuidies with<br />
.i (hicl>d1E)%1 I. tr' 'at>ljnIit f(.'us--the princi-
WARNER AND HUTTON<br />
pal orientations of physicians-have increased<br />
much more rapidly than those with<br />
a prevention theme; consistent with the<br />
increasing emphasis on personal health<br />
services. analyses oriented toward individual<br />
practitioner decision making appear<br />
lo be growing more rapidly tha. those with<br />
an orientation toward social or organizational<br />
decision malking; CEA, a more readily<br />
comprehensible technique, has come to<br />
dominate CBA.<br />
Some of the recent trends seem likely to<br />
ixprsist in the near fuiture, while others are<br />
more prohlematic We expect continued<br />
growth in the medical joumals' share of<br />
the literature. through increasing interest in<br />
CBA/CEA among nonphysician health<br />
professionals might restriet such relative<br />
growth in the physician-orienited literature.<br />
In any case. we would anticipate intensification<br />
of the trend tuward concern<br />
with individual practitioner decision making<br />
and increasing use of CEA relative to<br />
CBA. The r" .'1 n diagiosi s ¡;id treatmi('nt<br />
orien.it.is. . ;h..y' #)r IllI¡¡¡V nit ik' St1statined.<br />
Interest in thie .t Il spl)e ifice<br />
calpital-inteiisive inedical t'ehtu)logies<br />
shotild prinmiote a diagRosis n¿d treatiment<br />
ioctus, I)l!t the eIjerging, conven. COir healthl<br />
proaoftimn atndl disease IprT.iviint.>in cill<br />
re-verse the relative decvline iii ClBA/CEA<br />
interest in prevention.<br />
(;ro , ial'. ..<br />
h.s ' 1I;'ll gr.,sl)Jglill; ser.cyitss. witil (hi-<br />
¡,. 1 It (: IA/(:I :A ¡ruíilch.ils ii ¡t tie 'uh.t .bi<br />
¡im..r I'i In, lt}l í.. rí ..¡q¡lií .tlhm.. A. .. tila-<br />
, I 1,, l(,. ,.iitl, lotl.iit..I IbrI.tslz,' le. d1<br />
1 iil.<br />
- 391 -<br />
t l . tu li.Is t i ¡oqt , 11¡il e1¡1.1u . 1 1 . ti. 1<br />
n,.lIti-..ttrih,mmha misil>le tir delivering<br />
health senrvices. By eonitrast. sul:perior<br />
anjlyt'.s nmay achieve little impact .ss a const.llation<br />
of tiactors-et)nomnie incentivei.s<br />
politicatl concernas, etc.-itiay domiiiriate<br />
('Inhi(lh'r¿ationls ,)f sl('itl ('(ost-efe('z'tix<br />
('tl('N', '<br />
Actknowledrgment<br />
l I.I>. .h. u,di.,tt " '1'"- *,, .i.,ieg, d*I.. . *..! t Lh . thlm. 1..<br />
I .fl1. ll t . *il *" J'li,'l' * ' rt,dil ,iZ: r l II ta l.tll<br />
'., 1 " i I,, 1 I"tlh' ., , d%'.I '1,.. - , - I.,¡r .-- l.¡l' - .re dl<br />
I. -l. r1. Iv .ld<br />
MWciCAL. CARE<br />
I \ \..... , i i i . i t * st l 5. ", i<<br />
1t - y k .- I-- 11 "1 --l ,,, I." ,! " , ;. ' ..
SVol XVIII. l '>. . II<br />
:;Ei ¡ y7i<br />
1. 1 \\ 1,',i.¡ cc, \. h. Fh,-. .,Ie Ic,,'h . .. P...sl.,-, I.l-<br />
e, . ... h ... . ,e- I I .I1eie l . i.l'*. 1 , .1 - * ' .<br />
*'1 , I lIt 2,!111<br />
- 392 -<br />
C(:ST-BENEFI r AND C()ST-EFFECTIVENESS<br />
tiU. nd pietentd. Ann Agbtr: H«Iilth 4dn#m.í,atnduei<br />
Ptess (uidIiming).<br />
lr<br />
2. Congrtas tof thhe United States. iNlSI.F% 1 ¡cec ( í) l .ce (te c ,1ren> iill<br />
(1321ii¡.<br />
1 ' 4 7 eIIee11 c': le -1e1 ,aIe) I9els, ss eled) 3.3'Jlth ( : e'.<br />
%1.,l .1 hce l.I. . ,,-'. e .. lee Ilse It.áltl caf.' '..-- '!" e<br />
N%\ .¡ec.i? .e i alhl.s, c, 1 i'' i l- ce ..1 t -S) ."' 19 t9<br />
h e ,h e , I · %1, ,he , e [,, h, e.c¡ .
w'ARNER AND UL'TTOit'u ' . N Engl I .MIl- 176f.<br />
2L"a:,0I6.<br />
42. .htuw-nl.nam, S. Mc.Pil B. KaNP t J. iThe s-io ¡¡unJllenzd<br />
det ision. N i:ngl J Med 1976i.25:759<br />
43. Ilealhhy peouple:: h' S.irgeml (¢.i.ral', nr.i)rt<br />
i llhealthi h pru)iolils 1 i, ld dismdaít Ipr.'eiulionu.<br />
%\%,.lígt(m I) (':.: t1 .. (u>%-n.mniei Pn¡ltislg ()lt' e-.<br />
1979. (IIIEW $piallihiatulm eit. (PUiN 7W.55071<br />
44. Buiuike-r J. iar.ec D. .t(iiít-lvr) F. ' l*d. (:isit%<br />
riíLs .uid loi-it .. (ll't. tal ug'.r N ,,rk .t ()Oid,,r lu',i-<br />
4s. .%it. Pne 1977. ¥ A.<br />
4ti SIu'AL
# 23<br />
Morgan N. Jickson<br />
Jarnie, P. .>oGierfo<br />
Paula i)ichr<br />
Carolyn A. Watit<br />
Williamni Richardson<br />
- 394 -<br />
Hylv,,erecinomn t% one of ihe mol I'requentll<br />
performed major surgical procedurec in ¡he<br />
United State,, tloda)' l he facl thal incidence<br />
rate% var, t.onidcrahly heit4een l*ngland and<br />
the Uniled Stales." and vary even wilhin the<br />
iamne geographic area of the U .S .:' ha caused<br />
1i Io be ciled a, an example of a procedure<br />
which is ofien performed unneee.e,.armly. Although<br />
the surgery obviale,, . woatiitn'\ concern<br />
abhult he risks of an unplanned pregnanyv<br />
or cancer of ihe cervix or uterus and freec<br />
her from nienstruaion. it may expoNe her unneceNrily<br />
Iu i .¡.o:. , ,r nl..idlil) annd morhidity<br />
from the %u,.gery or it, complication,.<br />
Thi, study wUs undertaken ¡o an;^d/e the direil<br />
coti and direel hbnefti of electlive sirmple<br />
hytercciomy. Cosl of aliernaltive melhod, of<br />
contraception and their compliciilotn,, v cre<br />
not included in the analysi,.<br />
Rice4- ha, invetigated ¡he determination ol'<br />
indirect io.st of ilne,%. However. an ana.l) >1<br />
of elective hyntercctomy uNing direct co,,t.<br />
i.e.. charge, paid for inpatient and amhulaltor><br />
ecrvices. hae not been reportedJ 11,, ui,,iumed<br />
thai .uch :a report 'would provide informatiton<br />
uNelful in making the deiiimon au %u twhether ur,<br />
nol the proccdltire should he d.loul.ged.<br />
Anal> /n onlg direct i cor i ,¡void' the conirooer>)<br />
%urrounding an appropriaite .uiIluti(n of<br />
1. ,*hr." lfi.1 f, S, holio .0. ,hc ?!i r%1 s '3 4 .¡*hllí,lq.<br />
,il Il| P I ., :. I .I mc.. ln ( Ih.t'11o .% | i ' t# J.nN.e<br />
P. I.o4.erli. 1.)., M P.H.. 1s .e-sIJn I 't.f,:,'O I<br />
Hct.lih '\1ca:i , .&aid A. .! It ,*.(% .1 i.i<br />
Pha thlr. Pbil). i, A,..ss.fnl I>'"i*. ) sM,1 l .t ~ l.sll<br />
(.' rdI Ak. '1, 1 . II.I>., i' A'ssíl.,nl P,.WI.'.,<br />
~"rl,)l,:~ ..f',. k', s1.dA\ 1 I'ihP>, ', ,,I ' 3 ,, ,,I,,,<br />
,. 1 ¡1. , ,lth<br />
4 %illiam<br />
.,"c ,-.h , h. . % 1,,.c1 .1 i%1lsh. tic..llh .red1 ,(.mmíH, ,l.<br />
(<br />
'd,-lh , 5(r.li~ , ··
I,,qr *ir 'ilu.,i XV. Seplteri¡br 1978<br />
- 395 -<br />
year-old woman is justified on the basis of<br />
known risks and benefits." Deane and Ulene'<br />
compared hystereclomy and tubal ligalion as<br />
alternative sterilizaltion strategies in )oung<br />
women who desired permanent contraception.<br />
Using decision analysis and cost-benefit analyi,.<br />
they found thal al interest rates atove<br />
5/r. tubal ligation would be the preferred stralegy<br />
for all women over 20 years old. since il<br />
would be less cosily in both mortality and dollar<br />
dimensions. Cole and Berlin" examined the<br />
benefis and cosIs of elective hysterectomy for<br />
women at age 35 years. Assuming a 0.06r'/<br />
operative mortality rate and using rlhorecical<br />
cosi projections. the) concluded thal the opcration<br />
would increase life expectancy by 0.2<br />
years and Ihal ihe cosl of performing ihe operalion<br />
on one million women would exceed<br />
the benefil by $570 million when discounted<br />
to present value. They concluded that can.<br />
prophylaxis was not adequate justificaiion f.<br />
elective hysterectomy.<br />
Olher siudies have documented the adverse<br />
psychological sequelae' ° " ' thal may befall<br />
women undert .-,-,. .- sl:rectomy;: arker':'<br />
iuggested that the-;e were more likely lo be<br />
fomund in a woman in whom ihe procedure had<br />
been eleclive. The consensus of current literature<br />
concerning intangible considcralions favorn<br />
he notion that the cosis lo a woman of<br />
having an eleclive hysiereciomy outweigh thc<br />
benefils.<br />
Marib and Methods<br />
Data for the study were obtained from the Seattle<br />
Prepaid Health Care Project"' a fouryear<br />
wcial experiment designed lo evaluate<br />
the effect of provider financing and organization<br />
on patienl health status and utilization of<br />
medical services. Near-pIoor families residing<br />
in the Model Cilies larget arca of Seattle who<br />
met pecific income requircmcnt% were Clig,.<br />
ble lor the Project. The charge data (amount%<br />
paid io providers) were collected on paticnt%<br />
enrolled in a very comprehensive prcpaymcnt<br />
plan thai full) covered all medict:l servicc%<br />
provided by membcrs if a Physicians' Service<br />
Bureau (Kng C'ounty Med":aL'Blue Shieid)<br />
and community hospita.is The providers in.<br />
Cludedl alI couínunity hospital., pharmace%.<br />
and virtuall) all non-federal. n)n-.goup health<br />
coopcralive pihysiicians in King ('ouniv.<br />
WashingIon. There were no deductibles or<br />
other copayments. For ¡he services considered<br />
in this paper. and within the time period<br />
examined. information on amounts paid lo<br />
providers for inpatient and ambulatory medical<br />
services is essentially complete.<br />
The data base consisted of all paid charges<br />
thal occurred due lo the specified uterine-related<br />
gynecologic diseases listed in Table 1.<br />
These data were collecied by selecting information<br />
using three-digit diagnosis codes from<br />
ihe EiKghh Revi.sion. Internarional Clussificarion<br />
of Dise.ses. ' Some overlap occurred in<br />
the diagnoses between conditions which could<br />
be attribuied lo an intact uterus and ihose<br />
which would nol occur afler hysterectonmy.<br />
The categories included in the list are those<br />
w here vinually all of the cases could hbe ashted<br />
lo be attributable lo the presence of an<br />
nltact uterus. If most of the diagnoses in a<br />
d .gory could occur in a woman posthyster-<br />
.omy. this calegory was excluded. In this<br />
--. ¡. the charge data served as an estimate of<br />
ihe to,.' cosl of gynecologic services consumed<br />
because of uterine-relaled disease. In<br />
women who have had a hysterectorny.<br />
charges for none of ihese diagnoses should be<br />
incurred. and those foregone charges therefore<br />
would be considered tangible benefits,, of<br />
surgery.<br />
Table 1. Uterine-related diagoses used for<br />
dala s~let'ion<br />
tH I('I)A<br />
MalqnJan neop1am, uihc r ervxu U4t)<br />
Maiarnaln neoplasms ol ihe uiteus I.2<br />
Utenine fibrona t I«<br />
¢(her beni#n ncuplam% fd ihc uierus '19<br />
Ncu0plkm% uniptc'ised >< the uicru, 214<br />
Irun d
Tabi 2. Outpatlknl cose data<br />
- 396 -<br />
¡'.'.lt,ic Ilv hl'r'c lhl!' . A (C,.¡-B'. li, "c Anl'/sii<br />
Asc<br />
Pcnili I coshs<br />
AdjuIedJ io<br />
1972 dojlar, 1974 doII.tr.<br />
PcnxJl 2 o%<br />
'I ot.l<br />
uJuipJiien<br />
Paiient<br />
y )cars of<br />
c¢p>vurc<br />
Average<br />
annual<br />
cos per<br />
corl per<br />
woman (in<br />
rounded<br />
dollars!<br />
3-3 .4 . S7.363 S.20 .49th $12.Xh 349 537<br />
35-39 4.091 4.6Il '.27h 9.57 252 .39<br />
40-441 22.276 2..72 4.807 7.379 201) 37<br />
45-49 6.194 h .W9 3.1? 7 llIU.ihi 230 44<br />
50-.4 4.345 4.9110 2.6h1 7.
In.lumin- i',)i.eIu XV. Seph.irhb'r 1978<br />
- 397 -<br />
Table 4. Exposure snd expenditure data from Ihe Prepaid Health Care Project<br />
Calulated<br />
tota<br />
wolnan<br />
yc¿lr% of Oulpatlenl Inp a.cni<br />
Age e s rDoure co.:% Co ,<br />
36--4 349 S37 $44<br />
35- 9 252 39 59<br />
40-44 2tu1 37 44<br />
45-49 ?.10 44 mn<br />
-.4 191 39 25<br />
55-49 139 22 ]<br />
4tL IMi 9 2"<br />
1Ir .I prtjected cXp 'Ihe wotien<br />
Annualied .ivcragc cxpccted expenJturc per uoman<br />
tin ro)unded Jollar,,) or uterinec-relatcd didgnosc%.<br />
PV )ol PV of<br />
' orltl am.oun totail cot total .om)<br />
of projertecd for cach age for cach age<br />
Ih%s per wom;an tor ¡he spesified<br />
ulerine-rel.ilcd diiagnote%. This table also<br />
ahows the nel direct henefil as a result of a<br />
hylrcr¡lomy lo he $2.735. undiscounied.<br />
When discounied ait a 3.'# interet ratle. the<br />
value of the henefil is reduced ¡o $1.822. By<br />
discounting al a ¡ia te of 6.. 5'. the pteent valtc<br />
hecomea $1.240.<br />
und.'rgoin¡g l C.'r omy have ne: uterine paihology<br />
anu *:xpracnce no muiohidily rel'er;ble<br />
Io the uterut. T'hi% ib Ihe exlrcme cajc<br />
where there are no medical indicaiion% for the<br />
operation. If a henetit were found in analyzing<br />
an operation pertormed under Ihee condilions.<br />
then le%% rigid crileria would Nho.<br />
greater benefil. 4) The palient. are healilhy<br />
and experience minimum operatilv mortalily.<br />
5) 'I'herc arc no %ignificani complicalion, *)i<br />
the %urgcr>. excluisive of fatality. l'hi% .,%-<br />
:.umpnion %ould Icad lo a conerv¿alive etimale<br />
of the co,%¡% that might he realized h> the<br />
operation.<br />
Once the annualized cot projecllon% were<br />
hobtained. the .%ream fl' epcetcd henefiti werc<br />
dJiícounied to preenl value u-,ing a rate of re-<br />
Itull oíf t.; . a- ucll a. a `'S; lisCitinl tate tlt<br />
ici the %en%iisvlyt of the hnlingn 1ti Ih¡t ple.ent<br />
vahlue calcula¿lion%. The rallonaile for u,,ing<br />
¡hese Ito hglrc% i., dlicust,,ed heilo<br />
The mean ct),t of a hytercctoniy in ¡he Prepuid<br />
iHealth C'ae Projel sa is 51.h67 (s.d. J.<br />
.36h. N 22. Although both presenl value,<br />
1I the heneftil,, ¡e ilhin (ne standard deviation<br />
of Ihc co(P%. the imporiance of the discounl<br />
r.ate can he sen h! the faic. thalí. at a rate of<br />
1',. I¡lc ie ¡ .a -s,.d nl t heIllelil of .S18.-<br />
Rt'~<br />
I he calculaíion o., >' .gc-.pe k:i ,i:.-:, h,r ,iat<br />
wh:te.s '. italh a. dlsnini tale of h .';. there is<br />
. nc(l :o,( of $197 KRc.liS:? Ill I¡he stlialiegy<br />
,1 tihe ,snal lsl U; .s chosecn Io mt;lxiillmue the<br />
palaeni .mnd inpalient Itcalmenl o uerlcHlle lelalcd<br />
dJeaJae are iel forth mn I ahlk 2 und .l<br />
I'ahle 2 ,h( thatl the average annu¿al per :arpila<br />
c%.% rlo uherine-relalc(l anthul.fi(, utac<br />
eparciled dtrel htncarili. relaailtrn of an) of<br />
¡he icstli liti:. ;surnmplmri.r osf he hanal¿. .i%<br />
,ouIhl lireascc e the nel henelil (1o incrcei,, ihe<br />
nflt io I>r
- 398 -<br />
IElrtli o' Ilv.-4 r1h r ,y . A m. miagphl ;t imke the inal;ngible henefits<br />
:h: h1 -:llIgc! I IIe. enotg!; tI i.tln. eigh Ihc<br />
¡'e' a.llgilile .s" ¡l tilie diaLg'- o Dealae asld<br />
¡ 1cne -ehi,¡ ¡stksl lig.si¡ius'u tv{tjiii e,- preferahl<br />
tu h',a :sase %sier. %t ll sesta lsu a' ¡he<br />
g.uif st-,1o ual¡liag.ale .ag.allast iei.t uiaiei',lm a<br />
791
In#unrvlVolutn XV. September 1978<br />
hysierectomy for olher than medical indications.<br />
In addition lo thes financial considerations.<br />
mortaliiy calculations-performed by ihe auihors-were<br />
found lo be i, agreement with<br />
those of Cole and Berlin. Our analysis showed<br />
thal 30-year-old women undergoing elcclive<br />
hysterectomy could expect an average increase<br />
in life expectancy of 0.32 years. assuming<br />
a 0.06"i operative monality. However.<br />
half of those addilional years of life would be<br />
lived after the age of 75. and 7?8f would be<br />
lived after the age of 65. Thus. the piocedure<br />
would largely benefit elderly women al the expense<br />
of the young uaman who would no¡ survive<br />
the surgery.<br />
Whether a given woman should have a hys-<br />
Iereciomy is an individual decision. Whether<br />
eleclive hyslereclomies should he financed by<br />
third panies is a policy decision which is more<br />
likely io be at leas¡ partially influenced by direct<br />
cosi considerations. If such a decision resulted<br />
in an increase in the nel cost of care.<br />
such costs would he borne by ihe public<br />
Iwefm;c aid N«oM<br />
- 399 -<br />
through higher insurance premiums. If the decision<br />
resulled in a decrease in the nel costs<br />
of medical care. the public might be expected<br />
to benefit through Jecreased premiums. The<br />
findings of ihis study. and the companion analyses.<br />
suggest that a policy of permilling eleclive<br />
hyslerectomies probably would not be<br />
cosi-beneficial when direct costs are considcred.<br />
However. financial crileria are necessary.<br />
though nol sufficienl. for making policy<br />
decisions on a societal level.<br />
Wilh the increasing cosls of medical services.<br />
and the increasing role of government<br />
and ihird parlies. limits probably will be sel<br />
on ¡he amount of money the country will<br />
spend on heallh services. and on ihe type, of<br />
services ihat can be reimbursed. Cost-benefil<br />
;tinalyses such as this can provide information<br />
,ich is useful in making such decisions; even<br />
so. many olher factors will need lo be considcred.<br />
regardJless of whether the decision is<br />
bcing made by an individual. an underwriter.<br />
or the governmentl.<br />
Mead. . S ríti.al OeWulrgnJ ém .O, .tSlu. I#ipiuh. sun J.I,,rnul e/ . t ,trJ .41t(' ¿97>t0 I)HFW. Public<br />
Ilc4lth Serustc. S H li .R.sllc. Md 1975 Vol I.<br />
S.e I ablc I-'5 pp 1-71<br />
1',l M hR ksJ¢II -Inflation .nJ Rcl Intcrcei<br />
'..,,,, ,/ 1 ,,. -.. , 7 1 -. 2i '. Junc 19h<br />
' J,, urnil .Ju<br />
)<br />
2i9!<br />
-- i ? '
- 400 -<br />
TALLER SOBRE ENSEÑANZA DE LA INVESTIGACION OPERATIVA<br />
Y EI, ANALISIS DE SISTEMAS EN PROGRAMAS DE<br />
ADMINISTRACION DE SALUD<br />
El Taller se celebró en Caracas, Venezuela, del 8 al 12 de marzo de 1982, con<br />
los participantes que se mencionan en el Apéndice. Fue una actividad del Programa<br />
de la OPS/Fundación W. K. Kellogg de Educación en Administración de<br />
Salud y tuvo por objeto tratar sobre la incorporación de las técnicas de la investigación<br />
operativa y el análisis de sistemas; en los programas regulares de capacitación<br />
y en los de educación continua de administradores de sistemas de salud.<br />
Los objetivos específicos del Taller fueron:<br />
* Intercambiar experiencias entre los participantes en relación con la enseñanza de la<br />
invcstigación operativa y el an'álisis de sistelnas aplicados a los probclemas de atención elc<br />
salud.<br />
* Desarrollar un plan básico para la enseñanza en esos campos.<br />
* Seleccionar una bibliografia básica para ser usada en la actualización de educadores y<br />
administradores de los servicios de salud así como en el proceso educacional.<br />
* I)isci'ar un prog'ranla básico tic dlucación, continma en investigación operativ:a y aUl',lisis<br />
de sistemas para la actualización de profesores, investigadores y administradores en el<br />
sector salud.<br />
En 1970 no se conocía en América Latina la aplicación de la investigación<br />
operativa a los servicios de salud. En 1971 la OPS organizó un simposio sobre el<br />
análisis de sistemas en el que se recomendó el empleo prioritario de la investigación<br />
operativa a nivel hospitalario.<br />
Ese mismo año se inició un programa de verano en el Instituto Tecnológico de<br />
Estudios Superiores de Monterrey, México, en el cual estudiantes de ingeniería<br />
industrial y profesores participaron junto con administradores de salud en la<br />
definición y solución de problemas hospitalarios. Desde entonces, diferentes<br />
modalidades de este programa se han desarrollado en otras universidades de Colombia,<br />
Costa Rica, Chile, Perú, México y Brasil.<br />
En la actualidad se tiene conocimiento de unos 11 programas de ingeniería industrial<br />
y de sistemas en los cuales estudiantes de dicha especialidad han participado<br />
en investigacion.es de servicios de salud, y 54 programas que ofrecen<br />
capacitación en administración de salud.<br />
1 EI análisis de sistenlas y la investigación operativa se deben concebir de modo amplio para que<br />
comuprendan las técnicas cuantitativas de la ciencia de la administración, cuya aplicaició6n a la solución<br />
de problemas reales puede ser de gran utilidad. Dichas técnicas pueden ser de diferente grado de<br />
complejidad, desde la ingeniería industrial clásica hasta la programación matemática.<br />
4
Problemas identificados<br />
- 401 -<br />
Durante el T.,ller los participantes examinaron los diversos problemas 2 que se<br />
observanm en la Arierica Latina en la capacitación de administradores de salud en<br />
técnicas científicas de gestión. Dichos problemas se resumen seguidamente:<br />
Problemas en el sector salud<br />
* Los médicos, que son los responsables de la toma de decisiones en el sector, por lo<br />
general no conocen las técnicas del análisis de sistemas y la investigación operativa. Por<br />
consiguiente, las decisiones se toman con base en criterios subjetivos y políticos, sin el<br />
beneficio de metodologías cuantitativas y de información pertinente.<br />
* No se cuenta con información adecuada a nivel nacional, regional o local para tomar<br />
las decisiones. La solución de problemas en los sistemas de salud exige el desarrollo y la<br />
utilización de sistemas de información.<br />
* Los administradores de nivel intermedio no tienen los conocimientos adecuados de<br />
estadística descriptiva, análisis de sistemas y técnicas de evaluación requeridos en un enfoque<br />
racional del proceso decisorio.<br />
* Algunos administradores desconfían de los profesionales capacitados en técnicas científicas<br />
de gestión, lo que dificulta las relaciones interinstitucionales y perjudica el proceso<br />
educativo.<br />
* En el proceso de capacitación de administradores en métodos cuantitativos (especialmente<br />
de médicos) se corre el riesgo de que estos, con el poco conocimiento adquirido, se<br />
consideren "expertos" en la materia.<br />
* En las instituciones de salud se han creado pocas plazas para personas capaces de<br />
aplicar las técnicas científicas de gestión de problemas, por lo que en el sector salud las<br />
oportunidades de trabajo para profesionales en investigación operativa son limitadas.<br />
* Los especialistas en investigación operativa muestran una tendencia a concentrarse<br />
en los problemas pequeños, ignorando otros más importantes que tienen importancia nacional.<br />
Problemas el secaor educativo<br />
* La mayoría de los profesores universitarios no posee la experiencia adecuada en la<br />
aplicación del análisis de sistemas y la investigación operativa en el sector salud para<br />
motivar y enseñar eficazmente a estudiantes de administración de salud.<br />
* La enseñanza no debe consistir simplemente en disertaciones académicas. Para que<br />
sea eficaz, debe mostrar a los administradores de salud cómo aplicar las metodologías y<br />
técnicas a la solución de los problemas. Para ello se requiere de una adecuada preparación<br />
por parte de los docentes y de ayudas didácticas tales como casos de estudio y de un laboratorio<br />
sobre toma de decisiones.<br />
* En el diseño de programas de administración de salud es deseable la integración de las<br />
escuelas de ingeniería industrial y de sistemas, administración y medicina. Un problema<br />
fundamental de esta integración consiste en la orientación de las escuelas de administración<br />
e ingeniería hacia el sector privado o industrial; en general se tiene poca experiencia o<br />
poco interés en el sector público.<br />
* La mayoría de los profesores de salud pública en América Latina son médicos y, por<br />
lo general, muestran resistencia hacia la participación de otras disciplinas en el proceso de<br />
capacitación de personal de salud.<br />
2 Para un ejemplo específico véase: Pérez, C. E. Improving the Managerial Capabiliy of the Colombian<br />
Heaklh Systm, trabajo presentado en la reunión conjunta de ORSA/TIMS, Toronto, mayo de 1981.<br />
5
- 402 -<br />
* Como las universidades latinoamericanas por lo general no poseen los recursos financieros<br />
para mantener personal docente de calidad, existe un continuo éxodo de profesores<br />
hacia el sector privado y el extran. ero. Quizás cl problema más serio con que se enfrentan<br />
las instituciones educativas en América Latina sea precisamentc cl de contratar y mantener<br />
recursos humanos calificados.<br />
* Existen obstáculos institucionales y políticos que dificultan el establecimiento de relaciones<br />
formales entre las escuelas de salud pública, ingeniería y administración. Sin embargo,<br />
sin estas relaciones resulta difícil desarrollar programas educativos integrados.<br />
Estos obstáculos solo podrán superarse si las autoridades responsables de la administración<br />
de las escuelas y de las universidades reconocen este problema y la necesidad de encontrarle<br />
solución.<br />
Recomendaciones<br />
En e'l Taller se formularon una serie de recomendaciones orientadas al desarrollo<br />
de programas de educaión, tanto continua como regular, para administradores<br />
Programas educativos 3<br />
- 403 -<br />
1. Se recomienda desarrollar tres tipos de programas para enseñar investigación<br />
operativa y análisis de sistemas a estudiantes de administración de salud y<br />
analistas de sistemas en América Latina (OPS, IE, IO/AS):<br />
* Cursos cortos, principalmente para administradores y otros profesionales del sector<br />
salud. El curso típico durará de 16 a 40 horas y tendrá como objetivo enseñar al estudiante<br />
el empleo de metodologías y técnicas particulares en la solución de problemas reales de importancia.<br />
Se recomienda desarrollar una serie de estos cursos ya que es ilusorio pensar<br />
que un solo curso es suficiente. No se exigirán conocimientos previos de matemática. El<br />
curso permitirá al estudiante entender la perspectiva del enfoque de sistemas, apreciar la<br />
necesidad de utilizar información en el proceso de toma de decisiones y reconocer que cxisten<br />
individuos capacitados que pueden aplicar las técnicas de la administración científica<br />
en la solución de problemas del sector salud. Deberán planificarse cursos cortos parecidos<br />
para investigadores operacionales y analistas de sistemas a fin de lograr que su función en<br />
el sector salud sea más eficaz.<br />
* Programa de certificacidn, con una duración aproximada de 240 horas, para administradores<br />
de salud en ejercicio. El programa ofrecerá al administrador un conocimiento más<br />
profundo de las técnicas científicas de gestión. Debe ofrecerse, de preferencia, en la noche<br />
y fines de semana, para permitir al administrador/estudiante continuar con su trabajo<br />
regular. Como requisito en el campo de las matemáticas solo se deberá exigir conocimientos<br />
básicos de algebra.<br />
* Programa de maestria, de dos años, para administradores que deseen adquirir un conocimiento<br />
más profundo sobre investigación operativa y análisis de sistemas. Como requisito<br />
de admisión se deberá exigir conocimientos de cálculo. Se deberá ofrecer un segundo programa<br />
a nivel de maestría para preparar individuos con orientación técnica (ingenieros industriales<br />
y de sistemas, matlemáticos, fisicos) en la solución de problenmas del sector salud.<br />
Con base en la experiencia de los Estados Unidos de América, estos individuos podrán<br />
asumir en períodos relativamente cortos puestos administrativos en el sector salud y se<br />
convertirán en una fuente secundaria de administradores con formación cuantitativa.<br />
2. Los estudios de investigación operativa y análisis de sistemas dcpcndcn dce<br />
datos. La toma de decisiones óptimas se dificulta si no se posee información<br />
válida y confiable. Sin embargo, en la mayoría de los programas de administración<br />
de salud se presta muy poca importancia a este aspecto. Se considera que la<br />
OPS deberla llevar a cabo un seminario regional sobre "datos e informática en<br />
sistemas de salud", que podría incluir temas tales como: fuente y acopio de<br />
datos, diseño y desarrollo de sistemas de información, procedimientos de entrada,<br />
procesamiento, control de calidad, clasificación y análisis de datos, intercambio<br />
de información y otros temas afines (OPS).<br />
3. En cada país se deberá realizar una serie de talleres que reúnan a las autoridades<br />
del sector salud y técnicos competentes en el área de sistemas e investigación<br />
operativa. Dichos talleres deben estar orientados a la solución de problemas<br />
concretos de la prestación de servicios de salud (OPS, Organismos, IE).<br />
4. Se deberá organizar un taller ulterior para analizar las dificultades que se<br />
encuentren en la ejecución y actualización de las recomendaciones aquí for-<br />
3 La descripción de los programas educativos recomendados aparece en la pág. 12.<br />
7
- 401 -<br />
muladas. En este taller se discutirían los problemas relacionados con la ejecución<br />
de programas y proyectos, prestando especial atención a los obstáculos políticos,<br />
culturales y sociales. Deberían participar los asistentes en el presente Taller y<br />
otros individuos involucrados en proyectos de investigación operativa y análisis<br />
de sistemas a nivel nacional o regional en los países latinoamericanos (OPS).<br />
Rlccur.s ,y ilalerial didlcbti o auxiliar<br />
Antes del Taller, se realizaron dos estudios bibliográficos (español y portugués,<br />
e inglés) que sirvieron de referencia para el mismo y que también podrán<br />
utilizarse en los cursos que resulten de sus recomendaciones. Los estudios se concentraron,<br />
en primer lugar, en artículos y documentos que pudieran servir de<br />
base para la forn. 'ación de casos de estudios, útiles en la enseñanza de análisis<br />
de sistemas e investigación operativa para administradores de salud, y en segundo,<br />
en artículos que ilustraran la problemática de la prestación de servicios de<br />
salud.<br />
Se identificaron 60 artículos en español y portugués y se presentó un resumen<br />
de 43 de ellos.<br />
El cxanmen de las publicaciones en inglés (adelantado con la ayuda de la computadora)<br />
reveló miles de artículos relacionados con el análisis de sistemas y la investigación<br />
operativa en el sector salud. Se seleccionaron 116 artículos y 24 libros<br />
divididos en ocho subcategorías: evaluación de proyectos, planificación y programnación<br />
de recursos hum,aanos, distribución de recursos, estimación de dencanda,<br />
análisis de costo-beneficio, control de inventarios, evaluación de tecnologías y<br />
análisis de áreas de capacitación. En la selección se tuvo presente el nivel<br />
matemático de los artículos, teniendo en cuenta que se utilizarán para el adiestramiento<br />
de administradores, y se eliminaron aquellos artículos puramente teóricos<br />
y los que exigían conocimientos de matemática superior. Aunque se insistió principalmente<br />
en publicaciones recientes, se incluyeron varios artículos "clásicos" y<br />
otros que tratan temas de importancia a nivel de los países.<br />
5. Después de examinar los 116 artículos en inglés, los participantes seleccionaron<br />
38 para traducción al español. Estos artículos servirían como fuente y<br />
como base para el desarrollo de casos de estudio a ser usados en los tres tipos de<br />
cursos recomendados. 4<br />
En la serie final de publicaciones que se recomiendan para los programas de<br />
administración en salud también se deberán incluir 12 de los 43 artículos en<br />
español y 10 documentos distribuidos previamente por la OPS, así como la lista<br />
de los 24 libros en inglés ,, la bibliografía complementaria (artículos no seleccionados<br />
para traducción); de esta forma, los instructores contarán con una serie<br />
importante de recursos bibliográficos. Si bien los libros y los artículos complementarios<br />
están escritos en inglés, resultarán provechosos en los programas de<br />
4 En la pág. 14 se incluye la lista de los artículos.<br />
8
- 405 -<br />
maestrfa, donde se supone que los alumnos poseen conocimientos básicos de ese<br />
idioma (OPS, IE).<br />
6. A fin de mejorar la calidad de la enseñanza y la pertinencia dcl contenido<br />
de los cursos, se debe facilitar cl desarrollo de casos de estudio y de programas<br />
"paquetes" de computadoras como material didáctico auxiliar (OPS).<br />
* Se deberán desarrollar varios casos de estudio, que varíen en complejidad desde simples<br />
versiones de material disponible actualmente en publicaciones, hasta casos más complejos<br />
que pueden requerir 8-16 horas de clase y laboratorio para resolverlos. Los problemas<br />
seleccionados deben ser representativos de los que enfrentan los administradores en<br />
salud latinoamericanos. Los organismos nacionales o los analistas que hayan participado<br />
en la solución de problemas en el sector deben proveer el material básico para los casos.<br />
Otros casos de estudio pueden obtenerse de la expansión de algunos artículos incluidos en<br />
los estudios bibliográficos.<br />
* Para mejorar las clases (y algunos casos de estudio) se deben preparar programas de<br />
computadoras para sesiones de laboratorio. También deben obtenerse series de datos<br />
reales que permitan a los alumnos el uso de los programas a fin de lograr una mejor conaprensión<br />
de las técnicas particulares y su empleo en la solución de problemas reales.<br />
Como parte de este esfuerzo, la OPS debe fomentar el intercambio de este tipo<br />
de información entre universidades de América Latina y el Caribc.<br />
D)cbcn circularsc resúmenes de proyectos y tesis sobre problemas de los sistemas<br />
de salud. Estos proyectos pueden servir como casos de estudio y material<br />
para los "laboratorios" (OPS, IO/AS, IE, Organismos).<br />
7. Durante el Taller se trató de identificar lagunas en la literatura. Sc consideró<br />
quc existen varias áreas deficientes, tanto en inglés como en español (cuadro<br />
1). Estas deficiencias deberán identificarse con más detalle por representantes de<br />
los países latinoamericanos. Posteriormente, la OPS deberá comisionar publicaciones<br />
o iniciar estudios que puedan reducir estas deficiencias (OPS, IO/AS,<br />
Organismos).<br />
Cuadro 1. Areas en que existei lagunas ena a libralura.<br />
Tipo de curso<br />
Ar:a Cura corio PrograRla de cenrificación Programa de nuesirla<br />
Español Inglés Espaiol Inglés Espaiol Inglés<br />
Análisis de sistemas D D S D D D<br />
Informática D D D D D I)<br />
Análisis de decisiones D E D E O E<br />
Investigación operativa D E D E D E<br />
Conceptos generales D D D D D D<br />
D: Deficiente.<br />
S: Satislacorio.<br />
E: Excelente.<br />
9
- 406 -<br />
8. Los propios participantes y las instituciones docentes deben considerar la<br />
posibilidad de colaborar en la elaboración de programas "paquetes" para microcomputadoras,<br />
que se puedan usar para fines didácticos y para la solución de problemas<br />
reales. Lo anterior implicaría que los participantes de las diferentes instituciones<br />
utilicen máquinas similares y un lenguaje común. Los últimos desarrollos<br />
tecnológicos en el campo de las microprocesadoras pone a la disposición del<br />
usuario computadoras capaces de resolver problemas de gran complejidad a un<br />
costo relativamente bajo. En general, el costo de desarrollar los programas será<br />
mayor que el costo de la máquina; de ahí la gran importancia de la colaboración<br />
(IE, IO/AS).<br />
9. Teniendo en cuenta la considerable superposición de los temas considerados<br />
en los talleres sobre administración de salud organizados por la OPS, esta<br />
deberá comunicar a futuros talleres los resultados de los ya realizados, en especial<br />
cuando el tema lo justifique (OPS).<br />
10. La OPS debe explorar la posibilidad de obtener fondos para la publicación<br />
de un libro en español sobre investigación operativa aplicada a los problemas<br />
de los servicios de salud y dirigido a profesionales latinoamericanos; se deberá<br />
prestar especial atención a problemas regionales y nacionales. El libro podría iiicluir<br />
algunos casos de estudio (OP/; IO/AS).<br />
11. La OPS debe facilitar la preparación de un artículo que describa las labores<br />
del presente Taller y sus resultados. El artículo se publicará en una revista<br />
apropiada y serviría para fomentar más actividades de este género y mejorar la<br />
comunicación entre especialistas de los diversos países (OPS).<br />
12. La OPS debe facilitar la distribución de documentos de trabajo y tesis<br />
preparados en los Estados Unidos de América a educadores latinoamericanos. En<br />
especial se recomienda circular periódicamente el Catalog of Hospital Management<br />
Engineering Technical Papers publicado por el centro de distribución de ingeniería<br />
de gestión hospitalaria de la Asociación Americana de Hospitales; citas selectas<br />
de Hospital Management Abstracis, y resúmenes de tesis de maestría sobre problemas<br />
de los servicios de salud (que podrían obtenerse por medio de la<br />
Asociación de Programas Universitarios de Administración de Salud (OPS, IE).<br />
Programas de intercambio de información<br />
13. La OPS debe organizar la revisión de manera regular de las publicaciones<br />
pertinentes sobre servicios de salud (en español e inglés) y mantenerse enterada<br />
de las principales reuniones nacionales e internacionales de las asociaciones de investigación<br />
operativa y de salud pública. La información resultante debe enviarse<br />
sistemáticamente a los programas de administración de salud en América Latina.<br />
También se deberá incluir una lista de cursos y reuniones pertinentes a nivel profesional<br />
en los Estados Unidos de América y en países latinoamericanos (OPS,<br />
IO/AS).<br />
14. El intercambio de información en los talleres puede mejorarse mediante la<br />
10<br />
al
- 407 -<br />
presentación formal de informes sobre proyectos o actividades de investigación<br />
por parte de algunos de los participantes. Estas presentaciones podrían programarse<br />
antes de la inauguración del taller (OPS).<br />
Rmomrndaciones generae<br />
15. Para lograr una presentación más eficaz de las metodologías de investigación<br />
operativa y análisis de sistemas a los administradores de salud, formando<br />
siniultáineanente un grupo de analistas competentes, se debe dar prioridad al<br />
desarrollo de los cursos cortos y al programa de maestría de dos años; aunque es<br />
importante, el programa de certificación tiene menos prioridad. Según se indicó,<br />
se deberán desarrollar varios cursos cortos usando varios formatos y contenidos<br />
para satisfacer a grupos específicos (IE, IO/AS).<br />
16. Todos los participantes deben promover el desarrollo de programas de investigación<br />
operativa y análisis de sistemas con énfasis en el sector salud en los<br />
departamentos y escuelas de ingeniería industrial, medicina, administración y<br />
administración de salud. Debe insistirse en la creación de programas interdisciplinarios,<br />
en particular cuando solo una universidad está involucrada (IE,<br />
IO/AS).<br />
17. Un componente importante de los programas de certificación y de maestria<br />
deberá ser (por lo menos) un curso de investigación operativa en salud, conjuntamente<br />
entre las escuelas de ingeniería, salud pública y medicina. En ese curso<br />
debe incluirse, como mínimo, un proyecto en el que los alumnos trabajen<br />
como equipo interdisciplinario (IE).<br />
18. Hasta que las universidades latinoamericanas no se conviertan en los<br />
principales centros de formación de profesionales a nivel de maestría en estos<br />
campos, las universidades en los Estados Unidos de América y Canadá con[inuarán<br />
siendo los centros de formación a ese nivel en la Región. En consecuencia, es<br />
conveniente que las universidades latinoamericanas establezcan acuerdos institucionales<br />
con programas y escuelas de esos países. Las universidades latinoamericanas<br />
deben procurar que los programas de Norteamérica sean relevantes y<br />
tengan en cuenta las necesidades educativas de los estudiantes latinoamericanos.<br />
Si es posible, las tesis de grado deben tratar sobre problemas que sean también<br />
importantes en América Latina (IE).<br />
19. A medida que los programas de administración en salud se desarrollen en<br />
América Latina, es conveniente que se establezcan vínculos firmes y formales con<br />
los programas de ingeniería industrial, investigación operativa y de administración.<br />
Sin estos vínculos, las técnicas científicas de gestión no se integrarán eficazmente<br />
en los planes de estudio de administración en salud (IE).<br />
20. La OPS puede facilitar aún más la realización de proyectos de investigación<br />
y programas de cooperación entre profesionales de los Estados Unidos de<br />
América y América Latina si se informa a los participantes y a otros individuos<br />
interesados sobre problemas prioritarios y posibles fuentes de financiamiento<br />
(OPS, IE, Organismos).<br />
11
- 4C -o<br />
21. Es preciso reiterar que la investigación operativa y el análisis de sistemas<br />
exigen grupos interdisciplinarios para la solución satisfactoria de los problemas<br />
de prestación de servicios de salud. Esta realidad debc reflejarse cuidadosamente<br />
en la elaboración y ejecución de todos los programas y planes de estudio (OPS,<br />
IE, Organismos, IO/AS).<br />
22. Para que los estudios y proyectos sobre investigación operativa se traduzcan<br />
en acciones exitosas, es preciso quc los administradores de los sistemas involucrados<br />
participen en todos los niveles y puedan reconocer el valor de emplear<br />
técnicas científicas de gestión (OPS, IE, Organismos, IO/AS).<br />
Descripción de los programas educativos recomendados por el Taller<br />
Como ya se señaló, se recomendaron tres tipos de cursos: cursos cortos, programas<br />
de certificación y programas de maestría. Se convino en que el énfasis<br />
debe estar primero en los cursos cortos, después en los programas de maestría y<br />
finalmente en los de certificación.<br />
Cursos cortos. Los cursos (de 16 a 40 horas) se ofrecerán intensivamente durante<br />
un periodio de dos ai -inf:l( dlis o ceslpaci;ido< s durii';eiic v.i'iais seCIililnas o iii<br />
SCIInCStIC. Guino Cin un curso solo sc pucdc presentar Inaterial introductorio, sc<br />
deben programar una serie de cursos afines que se complementen mutuamente y<br />
que ofrezcan a los participantes una experiencia educativa más completa. Los<br />
cursos deberán incluir problemas a ser resuehlos por los aluminíos, individualiniciltc<br />
y cii grupo. lstas sesiones de laboratorio podrían usarse para familiarizar a los<br />
alumnos con la computadora, ya sea por medio de un juego, por ejemplo, la simulación<br />
de un sistema regional de salud o de un hospital, o mediante un modelo<br />
sencillo de asignación de recursos o de pronósticos.<br />
A continuación se presentan ejemplos de cursos cortos:<br />
* Curso para administradores de hospitales y sistemas de salud. No se requieren conocimientos<br />
de matemáticas, aunque una preparación básica en esa materia es aconsejable. En el curso<br />
se presenta una introducción a las técnicas de la investigación operativa y del análisis de<br />
sistemas, insistiendo en la comprensión de las posibilidades y limitaciones de los mismos.<br />
Los alumnos adquieren conocimientos sobre el enfoque de sistemas, análisis de costobeneficio,<br />
sistemas de información, fuentes.de datos y sobre trabajo en grupos interdisciplinarios<br />
5 . Asimismo, aprenden a reconocer los problemas que pueden solucionarse con<br />
estas metodologías, a evaluar el esfuerzo y tiempo aproximados que se requieren para la<br />
solución y a reconocer posibles barreras políticas y posibles fuentes de ayuda para la<br />
realización de estos estudios. L:s temas específicos a incluirse en este curso pueden<br />
referirse a problemas simplificados de decisión, problemas de asignación de recursos, problemas<br />
de planificación (CPM/PERT). El curso debe incluir un proyecto de grupo en el<br />
que se formule un problema no estructurado.<br />
5<br />
site sería un curso ideal, pero se reconoce que en un solo curso no se podrán presentar<br />
adecuadamernte todos esos temas.<br />
12
- 409 -<br />
* Curso para ingenieros indusriale, investigadores operaionales y personal de otras diJcipliwas ¿1cnucas<br />
intcresados en participar en la solución de problemas del sector salud. Los alumnos se<br />
familiarizan con los sistemas de salud y con los tipos de problemas comunes en el sector. Se<br />
presentan y discuten técnicas particulares para solucionar algunos de los problemas.<br />
Programa de crtificación (por lo general, de 240 horas). El programa estaría diseñado<br />
para el administrador de salud en ejercicio que desea un conocimiento más profundo<br />
que el ofrecido a través de una serie de cursos cortos, y también para el<br />
profesional que aspira a un cambio de profesión. La participación de los administradores<br />
de nivel intermedio en el programa puede significar para estos un ascenso<br />
de categorfa. Se requiere preparación matemática en materia de álgebra.<br />
El egresado del programa estará en condiciones de plantear y solucionar problemas<br />
cuantitativos sencillos (programación lineal, teoría de colas), realizar<br />
análisis básicos de costo-beneficio; recopilar y reducir datos (estadística descriptiva);<br />
usar programas "paquetes" de computadora para análisis; formular (pero<br />
no solucionar) problemas más complejos. Asimismo, tendrá un conocimiento<br />
básico'de los costos de la prestación de servicios de salud. Dcbc cnfiatizarsc cl concepto<br />
de equipo interdisciplinario. El curso debe incluir un proyecto de grupo de<br />
2-3 meses de duración.<br />
Los cursos del programa deben incluir una introducción a métodos cuantitalivos;<br />
un curso miaás riguroso en la aplicación de métodos cuantitativos; cursos<br />
introductorios en economía de la salud, bioestadística, y un curso en sistemas de<br />
información. Pueden considerarse cursos opcionales sobre teoría de planificación<br />
y evaluación en salud; métodos cuantitativos de planificación y evaluación, y<br />
comportaicenlo de las organizaciones en el sector.<br />
Programas d maestría (dos años). Se recomendaron dos tipos de programa de<br />
maestría. El primero estaría dirigido a administradores de hospitales y sistemas<br />
de salud que necesitan un adiestramiento más intenso que el ofrecido en el prograUma<br />
de certificación. Aunque los alumnos conserven sus trabajos regulares, se<br />
espera que residan en una institución académica por un período adecuado. Se<br />
deben exigir conocimientos de matemática a nivel universitario. El programa<br />
debe incluir todos los cursos del programa de certificación, un curso avanzado de<br />
estadística, un segundo curso de investigación operativa (modelos probabilfsticos)<br />
y un curso introductorio en econometría. Los alumnos deben participar en<br />
dos o tres proyectos de grupo durante el programa; estos proyectos deben realizarse<br />
como parte de un curso interdisciplinario.<br />
El segundo programa de maestría estaría diseñado para profesionales de ingeniería<br />
que desean solucionar problemas de los sistemas de salud. El programa<br />
tiene una orientación muy fuerte hacia la metodología y técnicas de la investigación<br />
operativa. Además, los alumnos deben familiarizarse con los conceptos de<br />
contabilidad de costos, principios de economía y sistemas de información. Se<br />
espera que los egresados del programa puedan desempeñar varias de las siguientes<br />
funciones:<br />
13
- 4i0 -<br />
a) Solucionar problemas de programación lineal y de inventario.<br />
b) Formular y analizar modelos estadísticos.<br />
c) Realizar análisis estadísticos avanzados (ANOVA y regresión múltiple).<br />
d) Diseñar estudios para recopilación de datos.<br />
e) Programar en un lenguaje de alto nivel (FORTRAN, PASCAL o PL-I).<br />
f) Diseñar la evaluación de programas.<br />
g) Realizar simulaciones mediante el uso de la computadora.<br />
h) Presentar informes técnicos.<br />
i) Interactuar con las autoridades del sector y participar en equipos interdisciplinarios.<br />
j) Tomar un problema no estructurado, resumirlo, formular un modelo matemático,<br />
identificar soluciones e implantar la mejor y más aceptable de ellas.<br />
k) Realizar estudios de planificación a largo plazo.<br />
Arlículos seleccionados para traducir al español<br />
Los artículos que los participantes recomendaron se tradujeran al español son<br />
los siguientes:<br />
1. Berkson, D., 1. Whipple y cols. Evaluation of an automated blood pressure measuring<br />
device intended for general public use. AmJ Public Health 69(5), May, 1979.<br />
2. Escudero, J. C.: On lies and health statistics: Some Latin American examples. In.j]<br />
Healtit Serv 10(3):421-434, 1980.<br />
3. Fetter, R. B., Y. Shin y cols. Case mix definition by diagnosis-related groups. Med<br />
Care 18(2) Supplement:1-52, 1980.<br />
4.Frerichs, R. y J. Prawda. A computer simulation model for the control of rabies in an<br />
urban area of Colombia. Managemenl Science 22(4):411-421, 1975.<br />
5. Greenland, S., E. Watson y R. Neutra. The case-control method in medical care<br />
evaluation. Med Care 19(8), August, 1981.<br />
6. Hartunian, N., Ch. Smart y M. Thompson. The incidence and economic costs of<br />
cancer, motor vehicle injuries, coronary heart disease, and stroke: A comparative analysis.<br />
AmJ Public Health 70(12), December, 1980.<br />
7. Lcv, B., G. Revesz y cols. Patient flow analysis and the delivery of radiology service.<br />
Socio-Econ Plan Sci 10:159-166, 1976.<br />
J 8. Meredith,J. Program evaluation techniques in the health services. AmJ Public Health<br />
66(11):1069-1073, 1976.<br />
j 9. Nutting, P., G. Shorr y B. Burkhalter. Assessing the performance of medical care<br />
systems: A method and its application. Mcd Care 19(3), March, 1981.<br />
10. O'Connor, R. W. y G. L. Urban. Using a model as a practical management tool<br />
for family planning programs. AmJ Public Health 62:1493-1500, 1972.<br />
11. Reisman, A., J. Mello da Silva yJ. B. Mantell. Systems and procedurcs of patient<br />
and information flow. Hosp Hcalth Serv Admin Winter: 42-71, 1978.<br />
12. Schoenbaum, S. C., B. J. McNeil yJ. Kavet. The swine-influenza decision. NEngl<br />
J Med 295(14):759-765, 1976.<br />
13. Shuman, L. J., H. Wolfe y R. Dixon Speas, Jr. The role of operations research in<br />
regional health planning. Operations Rescarch 22:234-248, 1974.<br />
i 14. Vraciu, R. Programming, budgeting, and control in health care organizations: the<br />
state of the art. Health Serv Res 14(2), Summer, 1979.<br />
./15. Duran, L. y A. Reisman. Design of alternative provider team configurations: experience<br />
in both developed and developing countries. Technical memo 947, Department<br />
of Operations Research, Case Western Reserve University, Cleveland, Ohio, 1980.<br />
14<br />
a
- 411 -<br />
¢ 16. Hancock, W., D. Magerlein y cols. Parameters affecting hospital occupancy and<br />
implications for facility sizing. HatiM Sarv Res 13(3), Fall, 1978.<br />
17. Hindl, A., N. Dierckman y cols. Estimating the need for additional primary care<br />
physicians. Health Serv Res 13(3), Fall, 1978.<br />
18. Reisman, A., B. V. Dean y cols. Physician supply and surgical demand<br />
forecasting: a regional manpower study. Managemen Science 19(12):1345-1354, 1973.<br />
19. Abernathy, W. J. y J. C. Hershey. A spatial allocation model for regional healthservices<br />
planning. Operations Rescarch/ 20(3):629-642, 1972.<br />
20. Goldman, J. y H. A. Knappcnberger. How to determine the optiiltum nuniber of<br />
operating rooms. Modan Hospital 111:114-116, 1968.<br />
21. Revelle, C., D. Bigman y cols. Facility location: A review of contex-free and EMS<br />
models. Heltli Sav Res 12(22):129-146, 1977.<br />
22. Brodheim, E. y G. P. Prastacos. The Long Island blood distribution systein as a<br />
prototype for regional blood management. Interfacs 9(5):3-20, 1979.<br />
23. Duraiswamy, N., R. Welton y A. Reisman. Using computed simulation to predict<br />
ICU staffing needs. J Nur Admin, February, 1981, pp. 39-44.<br />
24. Harrington, M. B. Forecasting area-wide demand for health care services: A<br />
critical review of major techniques and their application. Inquiry 14:254-268, 1977.<br />
25. Centerwall, B. S. y M. H. Criqui. Prevention of the Wernicke-Korsakoff syndrome.<br />
N EnglJ Mcd 299(6):285-289, 1978.<br />
26. Couch, N. P., N. L. Tilney y cols. The high cost of low-frequency events: The<br />
anatomy and economics of surgicil mnishaps. N EnglJ Mcd 304(11):634-637, 1981.<br />
27. Eisenberg, J. M. y A. J. Rosofi: Physician responsibility for the cost of unnecessary<br />
medical services. N EnglJ Mcd 299(2):76-80, 1978.<br />
28. Henry, J. B. y R. L. Roenfeldt. Cost analysis of leasing hospital equipment. Inquiry<br />
15(1):33-37, 1978.<br />
29. Klarman, H. E. Application of cost-benefit ainalysis to Ithc heilth services ai1il i le<br />
special case of tcchnologic innovation. IntJ Healh Setv 4(2):325-352, 1974.<br />
30. McGregor, M. y G. Pelletier. Planning of specialized health facilities: size vs. cost<br />
and effectiveness in health surgery. N EnglJ Mcd 299(4):179-181, 1978.<br />
31. Schwartz, W. B. Decision analysis: A look at the chief complaints. N EngilJ Med<br />
300(10):556-559, 1979.<br />
32. Willems, J. S., C. R. Sanders y cols. Cost effectiveness of vaccination against<br />
pneumococcal pneumonia. N EnglJ Mcd 303(10):553-559, 1980.<br />
33. Warner, K. E. y R. C. Hutton. Cost-benefit and cost effectiveness analysis in<br />
health care. Mcd Care 18(11):1069-1084, 1980.<br />
34. Kendall, K. y S. Lee. Formulating blood rotation policies with multiple objectives.<br />
Ma nmlt Sccet 26(11), November, 1980.<br />
35. Jackson, M. N., J. P. LoGerfo y cols. Elective hysterectomy: a cost benefit analyais.<br />
Inquiy 15(3):275-280, 1978.<br />
36. Evans, J. R., K. Lashman Hall yJ. Warford. Shattuck Lecture-Healih care in<br />
the developing world: Problems of scarcity and choice. N EnglJ Med 305(19):1117-1127,<br />
1981.<br />
37. McNeil, B. J. y S. J. Adelstein. Measures of clinical efficacy: The value of case<br />
finding in hypertensive renovascular disease. N EnglJ Mcd 293(5):221-226, 1975.<br />
38. McNeil, B. J., E. Keller y S. J. Adelstein. Primer on certain elements of medical<br />
decision making. N EnglJ Mcd 293(5):211-215, 1975.<br />
En el cuadro 2 se indica para qué tipo de programa es aplicable cada uno de los<br />
38 artículos seleccionados para traducir al español.<br />
15
- 412<br />
Cuadro 2. Tipos de programa en los que resultarán más provechosos<br />
los artículos seleccionados para traducir al español.<br />
Aniculo No. Prograrma de Programa de Curso corto<br />
maestria certificación<br />
1. x X<br />
2. X X X<br />
3. X<br />
4. X<br />
5. X Xa<br />
6. X X X<br />
7. X<br />
8. X X X<br />
9. X X X<br />
10. X X<br />
11. X X<br />
12. X X X<br />
13. X X X<br />
14. X X<br />
15. X X X<br />
16. X X X<br />
17. X X X<br />
18I. X<br />
19. X<br />
20. X<br />
21. X X<br />
22. X X Xa<br />
23. X X X<br />
24. X X X a<br />
25. X X X<br />
26. X X X<br />
27. X X X<br />
28. X X X<br />
29. X X X a<br />
30. X X X<br />
31. X X Xa<br />
32. X X X<br />
33. X X<br />
34. X X<br />
35. X X X<br />
36. X X X<br />
3 7 y 38 X X X<br />
aOpcional.<br />
Artículos selcccionados en español<br />
Se seleccionaron los siguientes artículos, que se recomendó que la OPS distribuyera,<br />
al igual que sus propias publicaciones pertinentes a este campo.<br />
1. Ackoff, R. L. Posibilidades actuales de la investigación operativa. Administración de<br />
empresas 5(50):125-135, mayo, 1974.<br />
16<br />
U<br />
U
- 413 -<br />
2. Barrenechea, J. J. La selección de prioridades como integrante del proceso de decisión.<br />
Medicina sanitariay administración de salud (Tomo II, Parte 3: Atención de la salud),<br />
págs. 206-214.<br />
3. Dunia, W. A. de, C. Carmendia y cols. Servicio de emergencia. Consideraciones conceptuales<br />
sobre sufuncionamiento y organiracidn especial (Centros ambulatorios de salud y hospital general de<br />
200 camas. Nota técnica 76-NTe-13). Ministerio de Obras Públicas de Venezuela, Direcci6n<br />
General de Desarrollo Urbanístico, Secretaria Técnica, Unidad de Investigación,<br />
1976.<br />
4. Facultad de Ingeniería, Universidad de Costa Rica, y OPS, estudio de ingeniería industrial<br />
en el subsistema "Procesar y distribuir alimentos" del Hospital Nacional de<br />
niños. 1974.<br />
5. Grundy, F. y W. A. Reinke. Investigaciones de práctica sanitaria y métodos mnatemáicos de<br />
gestión: Capitulos 1, II, IV y VIII: OMS, Cuadernos de Salud Pública 51, 1974.<br />
6. Novaro, S. Asignación de camas de servicios de hospitalización: una técnica posible.<br />
Atmción médica 2(1-2), 1973.<br />
7. Rodríguez, R. J., L. C. Arcón y L. A. Almeida Pimentel. Estado actual del sistema<br />
de control de pacientes del hospital de clínicas. Bol Of Sanit Panam 84(6):493-504, 1978.<br />
8. Schmidt, L. Consecuencias tcnicas de investigación del sistema de información para la salud,<br />
Veneu/ela (SIS-V/80). Ministerio de Sanidad y Asistencia Social, Dirección dc Planilicaci6n,<br />
Presupuesto e Informática, Comité de Informática, 1980.<br />
9. Schmidt, L., E. Zorilla y M. Quintero. Sistema automático de monitoreo de señales<br />
EKG para una unidad de cuidados coronarios. Trabajo presentado en el Congreso Internaciuoid<br />
dc Sistenuls, Venezuela, julio dc 19111.<br />
10. OPS y Departamento de Ingeniería Industrial, Instituto Tecnológico y de Estudios<br />
Superiores de Monterrey, Nuevo León, México. Análisis de sistemas en lavandería de un<br />
hospital general. Washington, D.C., Documento HRR/13/2-B, 1976.<br />
En el cuadro 3 sc indican los cursos para los que son aplicables los artículos scleccionados.<br />
Cuadro 3. Tipos de programa en los que resultardn mnás<br />
provechosos los artículos en español.<br />
Arliculo No. ,lura,,ira ,acsrtía de cerfilicación rliglaa lc Curso colou<br />
1. X X X<br />
2. X X<br />
3. X X<br />
4. X X<br />
5. X X X<br />
6. X X<br />
7. X X<br />
8. X X<br />
9. X<br />
10. X X<br />
A continuación se incluyen como ejemplo los contenidos de varios cursos, que<br />
podrán adaptarse según las necesidades.<br />
17
- 4.!4 -<br />
EJEMPLOS DE CONTENIDO I)E LOS CURSOS CORTOS<br />
Introducción a la investigación operativay al análisis de sismas para profesionales de salud (40 horas)<br />
1. Introducción a los conceptos de análisis de sistemas, planificación, evaluación y toma<br />
de decisiones. Se debe presentar inicialmente una visión panorámica y un modelo conceptual,<br />
del análisis de sistemas aplicado a los problemas de prestación de servicios de salud.<br />
Este modelo debe servir de referencia a medida que se presenten los temas con mayor profundidad.<br />
2. Definición de un sistema de decisión, tipos de decisiones, tipos de modelos. Discusión<br />
sobre los niveles de toma de decisión.<br />
3. Introducción a la formulación de modelos; el arte de mnodelaje, modelos típicos de<br />
problemas importantes en los sistemas de salud.<br />
4. Presentación de un caso o de un microproyecto que los alumnos deben desarrollar<br />
durante el curso. El énfasis debe estar en la formulación del problema. La solución de una<br />
parte del problema puede lograrse usando programas "paquetes" para computadoras.<br />
5. Introducción a métodos de planificación y evaluación, incluyendo la preparación de<br />
diagramas, CPM (método de la ruta crítica), PERT (técnica para la evaluación y control<br />
de programas), gráficas de Gantt. Se debe incluir la discusión de métodos para la evaluación<br />
de procesos y de resultados utilizando ejemplos apropiados.<br />
6. Introducción a modelos de asignación de recursos. Presentación dc tan caso sencillo<br />
de programación lineal. Demostración de la técnica gráfica de solución. Estudio de<br />
supuestos en la formulación del problema. (Es deseable el uso de la computadora.)<br />
7. Introducción a fuentes y al acopio de datos. Deben estudiarse los problemas de la administración<br />
y procesamiento de datos, la confiabilidad de los datos, sistemas de información<br />
y posibles áreas problema.<br />
8. Introducción al análisis de costo-beneficio y a presupuestos. Deben examinarse el<br />
valor del dinero en el tiempo, cálculo de costo de proyectos, ejemplos sencillos de análisis<br />
de costo-beneficio, definición y cálculo de la tasa interna de retorno y relación costobeneficio.<br />
9. Análisis de costo-beneficio. Definición de beneficios y costos marginales, matriz de<br />
impacto-incidencia, ejemplo completo de costo-beneficio mediaite cálculos Imanlllu;cs. (.Es<br />
deseable un ejemplo utilizando la computadora.)<br />
10. Mercadeo de los servicios de salud. Definiciones básicas, diferencia entre venta y<br />
mercadeo, planificación estratégica, aplicaciones específicas al sector.<br />
11. Introducción al concepto de incertidumbre. Conceptos básicos de probabilidad,<br />
eventos, estimación y cálculo de probabilidades, el teorema de Bayes, distribuciones y<br />
valores esperados.<br />
12. Análisis de decisiones, incluyendo árboles de decisión, alternativas, resultados, experimentos,<br />
valores y su obtención. Análisis e interpretaciones del problema de decisión,<br />
estudios de cosas sencillas. Las sesiones de laboratorio deben incluir un caso completo<br />
sobre análisis de decisión.<br />
13. Técnicas de pronóstico. Concepto' de promedio móvil, suavización exponencial,<br />
cuadrados mínimos. Interpretación de regresión simple. Estudio de caso; es deseable el<br />
uso de programa dc computadora.<br />
14. Administración de inventarios y materiales. Costos importantes en el sistema de inventarios.<br />
Modelos básicos de inventario, tamaño de lote y nivel de orden.<br />
15. Ejecución de estudios de investigación operativa y análisis de sistemas. Grupos interdisciplinarios,<br />
trabajo con autoridades, validación de los resultados de los estudios,<br />
estudio de obstáculos en la implantación de los resultados.<br />
18<br />
dl
- 415 -<br />
Curwso (8 a 16 horas) para profesionales de saltud 6<br />
Tema Curso de Curso de Curso de dos días<br />
un día dos días (con matemática)<br />
Introducción al análisis de sistemas I hr. I hr. I hr.<br />
Concepto de sistemas 1 1 I<br />
Técnicas gráficas 2 5 5<br />
Técnicas matemáticas . - 8<br />
Acopio de
- 416 -<br />
9. Otras técnicas de acopio de datos: estudio de tiempos; análisis de asociación, cuestionarios.<br />
10. Sesión de trabajo sobre medición.<br />
11. Análisis de costos: medidas de costos; cálculo de datos; criterios no monetarios;<br />
comparación de métodos.<br />
12. Estadística elemental para análisis dc diferencias; prueba de hipótesis; interpretación<br />
de datos.<br />
13. Sesión de trabajo sobre evaluación de resultados.<br />
14. Importancia de los resultados de los estudios sobre mejoramiento de métodos.<br />
15. Sesión de trabajo: informes y críticas de proyectos.<br />
Curso/Seninario sobre invesligación de sistemas de salud (45 horas)<br />
Este curso está programado para estudiantes de administración de salud y de ingeniería<br />
industrial/investigación operativa que desean profundizar sus conocimientos en la aplicación<br />
de métodos cuantitativos a los iproblemas de los sistemas de salud. Además dc las discusiones<br />
académicas, los participantes formarán pequeños grupos interdisciplinarios para<br />
resolver un problema real de un hospital o del sistema de salud. Los temas a tratar en el<br />
seminario son:<br />
1. Introducción a la ingeniería industrial/investigación operativa aplicadas al sector<br />
salud.<br />
2. Evaluación del sistema de distribución de dosis unitarias de medicamentos.<br />
3. Modelos de costos hospitalarios: distribución escalonada de costos; microcosteo.<br />
4. Reembolso, modelo de incentivo: enfoque de ingeniería industrial.<br />
5. Modelos de evaluación de utilización de servicios.<br />
6. Modelos para la dotación de personal de enfermería.<br />
7. Modelos de reembolsos predictivos.<br />
8. Agrupación de hospitales para control de reembolsos y costos.<br />
9. Sistemas de admisión y programación de cirugías.<br />
10. Aplicaciones de la programación lineal: planificación de menús en hospitales,<br />
radiología terapéutica.<br />
11. Planificación regional: localización de una red de centros de salud.<br />
12. Servicios médicos de urgencia: sistema de información; simulación de sistemas de<br />
urgencia; evaluación del personal paramédico.<br />
13. Análisis y modelos de economía de salud.<br />
14. Evaluación de la eficacia de la atención médica.<br />
isuemas de itformación y evaluación de la calidad de la atención médica (30 horas)<br />
Este curso está programado para planificadores y administradores de los servicios de<br />
salud. Presenta una visión panorámica del uso de la información y de la tecnología del procesamiento<br />
de datos para la planificación, administración y control de los sistemas de<br />
salud.<br />
1. Origen, naturaleza y uso de la información en los sistemas de salud; documentación<br />
médica; registros administrativos.<br />
2. Inforinación para los procesos de torra de decisiones; importancia y objetivos de esa<br />
enseñanza de informática al personal de salud.<br />
3. Objetivos de los usuarios de la información; niveles funcionales; núcleo de centralización<br />
o de distribución de los sistemas de información; impacto de la información en las<br />
organizaciones.<br />
20
- 417 -<br />
4. Necesidades de los administradores; información para administración y planificaci6n.<br />
Qr 5. Análisis de sistemas; proyectos sobre análisis de sistemas; planificación y control de<br />
los proyectos; acopio y distribución de datos; proceso para establecer sistemas de información.<br />
6. Computadoras y automatización: conceptos básicos, procesamiento electrónico de<br />
datos; archivos y estructuras lógicas; bancos de datos; computadoras y sus componentes,<br />
centros de procesamiento de datos.<br />
7. Opciones para el procesamiento de datos: sistemas centralizados, descentralizados y<br />
distribuidos.<br />
8. Aplicaciones del procesamiento de datos en los sistemas de salud; ventajas e inconvenientes<br />
del uso de computadoras.<br />
9. Sistemas de información para la evaluación y el control; métodos de evaluación del<br />
uso y de la calidad de los servicios, auditoría médica.<br />
Mitodos cuantihtais y analílicos en administración de salud (40 horas)<br />
Este curso 8 está diseñado para: 1) desarrollar en el participante la apreciación y comprensi6n<br />
de los procesos básicos del análisis de sistemas, toma de decisiones y control;<br />
2) identificar la influencia de estos procesos en las actividades y responsabilidades del administrador<br />
de salud. Se discuten algunos modelos básicos de decisión y control así como<br />
la metodología del análisis de sistemas, ciencia de gestión y economía. Se recalcan las ventajas<br />
y limitaciones de estos modelos para la toma más eficaz de decisiones en el sector. Entre<br />
otros, se requieren conocimientos de álgebra a nivel universitario, álgebra lineal básica,<br />
probabilidad y estadística básicas.<br />
1. Revisión general de la literatura relacionada con el análisis de sistemas/investigación<br />
operativa y ciencia de gestión y el sector de la salud.<br />
2. Concepto y análisis de sistemas: un prólogo para la toma de decisiones en el sector.<br />
3. Modelos cuantitativos y sus funciones en la toma de decisiones y control en el sector<br />
salud.<br />
4. Modelos elementales para el análisis de decisiones determinísticas: inventarios y<br />
administración de proyectos.<br />
5. Modelos complejos de decisiones determinísticas: programación matemática.<br />
6. Solución de problemas de programación lineal por computadoras; análisis de sensibilidad.<br />
7. Acopio de datos apropiados para la toma de decisiones en el sector salud: técnicas de<br />
medidas.<br />
8. Aplicaciones de la programación entera y programación con metas en el sector de la<br />
salud.<br />
9. Análisis de costo-beneficio y costo-eficacia: un modo fundamental de pensar en la<br />
toma de decisiones en el sector de la salud.<br />
10. Realimentación, control y evaluación de programas para una administración más<br />
eficaz de la atención en salud.<br />
11. Temas especiales tratados por conferencistas invitados.<br />
8 Curso desarrollado por Barnett R. Parker, Ph.D., Escuela de Salud Pública, Universidad de<br />
Carolina del Norte, Chapel Hill.<br />
21
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Apéndice<br />
Participantes en cl Taller<br />
Ing. Moisés Arteaga Cabrera, Ministerio de Planificación, La Paz, Bolivia<br />
Carmela Calapinto de Rosales, Ministerio de Sanidad y Asistencia Social, Caracas, Venezuela<br />
Ing. Antonio dal Fabbro, Escuela de Salud Pública, Sao Paulo, Brasil<br />
Dr. Mariano Fernández, Ministerio de Sanidad y Asistencia Social, Caracas, Venezuela<br />
Dr. David R. Gómez Cova, Escuela de Salud Pública, Universidad Central de Venezuela,<br />
Caracas, Venezuela<br />
Dr. Pedro Guédez Lima, Dirección de Salud Pública, Ministerio de Sanidad y Asistencia<br />
Social, Caracas, Venezuela<br />
George Kastner, Instituto de Estudios Superiores en Administración, Caracas, Venezuela<br />
Ing. Carlos Enrique Pérez (Relator), Universidad de Pittsburgh, Pittsburgh, Pensilvania<br />
Ing. Victor L. Pérez, Universidad de Chile, Santiago, Chile<br />
Ing. Diego Prieto, Universidad de Los Andes, Bogotá, Colombia<br />
Ing. Carlos M. Quesada Solano, Escuela de Ingeniería Industrial, San José, Costa Rica<br />
Arnold Reisman, Universidad Case Western Reserve, Cleveland, Ohio<br />
Dr. RobertoJaime Rodríguez, PROAHSA, Hospital das Clinicas, Facultad de Medicina,<br />
Universidad de Sao Paulo, Sao Paulo, Brasil<br />
Dr. Richard H. Shachtman, Escuela de Salud Pública, Universidad de Carolina del<br />
Norte, Chapel Hill, Carolina del Norte<br />
Dr. Larry J. Shuman (Relator), Universidad de Pittsburgh, Pittsburgh, Pensilvania<br />
Organización Panamericana de la Salud<br />
Dr. Humberto Moraes Novaes, Asesor Regional y Coordinador del Programa OPS/<br />
Kellogg de Educación en Administración de Salud, División de Recursos Humanos e<br />
Investigación, Washington, D.C.<br />
Ing. Jorge Ortíz, Asesor Regional en Investigación de Servicios de Salud, División de<br />
Recursos Humanos e Investigación, Washington, D.C.<br />
Ing. Jorge Peña Mohr, Asesor Regional en Administración Institucional, División de Servicios<br />
Integrados de Salud, Washington, D.C.<br />
22
MOISES ARTEAGA<br />
DR. DAVID GOMEZ COVA<br />
DR. ANTONIO DAL FABRO<br />
DR. CESAR HERMIDA<br />
DR. GEORGE KASTNER<br />
DR. CARLOS PEREZ<br />
DR. VICTOR PEREZ<br />
- 419 -<br />
LISTA DE PARTICIPANTES<br />
Subsecretario de Planificacion<br />
La Paz, Bolivia<br />
Escuela de Salud Publica<br />
Caracas, Venezuela<br />
PROAHSA - Hospital Das CUinicas<br />
Ave. 9 de Julh 2029<br />
01313 Sao Paulo, Brasil<br />
Curso de Postgrado en<br />
Administracion de Salud<br />
Facultad de Medicina<br />
Calle Iquique s/n<br />
Quito, Ecuador<br />
Instituto de Estudios Superiores<br />
Final Calle Occidente<br />
San Bernandino<br />
Caracas, Venezuela<br />
Inadustrial Engineering Dept.<br />
University of Pittsburgh<br />
U.S.A.<br />
Departamento de Industrias<br />
Universidad de Chile<br />
Santiago, Chile<br />
DR. DIEGO PRIETO Escuela de Ingenierja Industrial<br />
Universidad de los Andes<br />
Bogota, Colombia<br />
DR. CARLOS QUESADA Escuela de Ingenieria<br />
Industrial<br />
Universidad de Costa Rica<br />
San Jose, Costa Rica
DR. ARNOLD REISMAN<br />
DR. ROBERTO J. RODRIGUEZ<br />
DR. LARRY SHUMAN<br />
- 420 -<br />
Case Western Reserve University<br />
Cleveland, Ohio<br />
PROAHSA<br />
Ave. 9 de julho 2029<br />
01313 Sao Paulo, Brasil<br />
Industrial Engineering Department<br />
University of Pitt8burgh<br />
U.S .A.<br />
PR<strong>OF</strong>ESSOR RICHAR SHACHTMAN University of North Carolina<br />
Rosenan Hall 201H<br />
Chapel Hill, N.C. 27514<br />
DIVISION DE RECURSOS HUMANOS E INVESTIGACION<br />
DR. HUMBERTO M. NOVAES Coordinador<br />
ING. JORGE ORTIZ Investigador Operacional<br />
DIVISION DE SERVICIOS INTEGRADOS DE SALUD<br />
SR. JORGE PENA MOHR Asesor Regional en Adinnistracion<br />
de Salud<br />
<strong>OF</strong>ICINA SANITARIA PANAMERICANA- CARACAS<br />
DR. BARRY W. WHALLEY RA-II Venezuela<br />
4<br />
1<br />
la<br />
4