BOOKS OF RtfiDIfGS - PAHO/WHO

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Michael B. Harrington Forecasting Areawide
Demand For Health Care
Services: A Critical
Review of Major
TeChniques And
Their Application
Since well before Cassandra, people havc
sought to forecast the future. In modem times,
forecasting methods have adopted fairly scientific
guises. But it is not clear that their predictive
accuracy has improved appreciably over
.hat of their predecessor. This is especJally
utre of methods applied lo large-scale public
problems, such as areawidec health planning.
Improved methods have been offset substantially
by the greater complcxity, more rapid
change, and more pervasivc interdependence
characceristic of modern society. Forecasting
skill have grown, but so has the difficulty
of the ¡;.',.
The impetub for developing improved methods
for use by areawide health plannera, begun
nder tbc Comprehensive Health Planning
lesilation of 1966,' no doubt will be reintorced
by the Health Planning and Resources
Developmct Act of 1974 (P.L. 93-641).2
M1mut . Hia po~ i D, bs Senior Auociat ltot
the Sysclm Evaluallon Departnen, CACI. Inc.-
Federal (Arlaliton, VA 22209), and Professor of
ialth Economcs, Souhetemrn Unlveity.
fai marerch or thbis piapr w completed under
Contract liA 230-76.00~ aeored by the Bureau
Healthb Planaing aMd Rmurces DevelopmcnM.
Health Resources AdminiArítion, DHEW. In de.
veop~n ibs par, Ub aubhor benited grealy
(mam prticipatíAon ia eries o( three ympoi~ Wpon.
ored by thibe Bureau of Health Planning d Re.
bouets Developenl, DHEW. durinl the fali of
1974 und prling of 1975. Of coun. neither BHPRD
anr tib other rympoml paricipans are responlible
for shorioominp thir paper may cntain. In additbn.
aluable crituncsm was rendered by Sarh P.
Far of the WAublni Office of Arthur Young
& Comniay; Wiliam Orfes. Dcprnment ot Medci.ne
and SurUlry. VA(Mas Admnlnt(mbul . WuashJion.
D.C.; and Dr. Chester McCall. Manager. Syucms
Evaluation Dcpanmen, CACI. Inc.-Federnl Arlingl
to. VA.
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Somewhere betwcen perfect forecasts of the
health care futurc and none at all lies a "zonc
of feasible forccasting" (i.c., forccasts both useful
and within the capabilities and budgcts of
health planncrs). This paper explores the zone
of feasible forecasting, by considering the following
points:
O The objectives of forecasting in areawide
health planning;
0 Specific factors contributing to thc demand
for health services that enter into any serious
forecasting effort;
O Major sources of change and continuity in
the areawide health care system that are
identified in conjunction with demand forecasts;
O Six generic kinds of forecasting techniques
in the health planning context, including
an evaluation of the strengths and weaknesses
of each;
C A simple framework through which each
forecasting method might be brought to
bear most effectively;
o Some apparent dimensions of the "zone of
feasible forecasting," given the current state
of the art.
Objectlves of Effective Forecasting
At least three major objectives for forecasting
areawidc health service requirements recur in
public discussion:'
1 Improving the foresight and skill with which
public and private health care resources are
allocated. Improved forecasts would help
achieve lhis objective primarily by providing
an arcawide "picture" of future necds
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