BOOKS OF RtfiDIfGS - PAHO/WHO

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- 370 -
Application of Cost-Benefit Analysis to Health Setvices /
in which people are so classified. From other studies it would appear that a host f(
factor such as health insurance, earnings as an expression of the value of time, ae, arad
the supply of providers, ae important determinants of the demand for physici a
ei ices (1 2).
The assertion that the supply of services for sick care is inelastic is not unique to
Garfield. In the area of trends in the education of physicians, which ltakes longr and
therefore responds more slowly than any other health occupation, my own readin
indicates that even this system has been somewhat responsive, even while insiting that
clas size in medical school must be kept small (18, p. 101), and still moro responsive
after the policy decision to expand enrollment was made and implemented by funding.
Whether the supply response has been sufficient to meet rising demand is, of course, a
different issue.
The most serious reservation I have about Garfield's position touches closely on the
nature and function of cost-benefit analysis. If complete prepayment serves to create a
condition of perpetual excessive demand, then some rationing or control measures are
dearly indicated. Why assume, without c¿mparing alternatives, that automated
multiphasic screening is the most appropriate instrumentality? It seems to me that wher
the stated purposes of a program change, so should the menu of alternatives to be
considered.
Two reports by Collen (101, 102) on the cost of screening fil a real need. Two
measures are presented-cost per test and cost per screening. Cost per test reflects only
direct departmental costs, whde cost per screening incorporates an allocation of overhead
expense. The article published in 1970 (102) offers a costing rule: in order to allow for all
costs incurred, double the reported cost per test. The earlier article (101), which appears
to present essentially the same data, suggests a blow-up of 50 per cent; I am unable to
account for the difference.
Since the screening process is automatic, the capital equipment is indivisible, and all
procedures are schedulable, economies of scale are to be expected. The larger the scale of
operation, the lower is the average unit cost. However, to achieve the lower cost, full
utilization of existing facilities is essential. Accordingly, it is said to be advantageous to
have available a source of stand-by patients, such as those awaiting admission to the
hospital (103).
Collen's second article (102) goes beyond cost per test or per screening, and reports
cost per positive case. For manmmography a prevalence rate of 1.2 per cent converts the
unit cost of S4.90 into a cost per positive case of $408. Since one-fifth of the women
with positive mammograms have cancer of the breast, the screening cost per true positive
case is 52,000. His doubling rule would raise the cost to S4,000. The cost of diagnosis for
all five women and of treatment for one is still excluded.
The proportion of false positives is a function not only of the accuracy of the
screening test but also of the prevalence rate (113, 114). There are two reasons for aiming
to keep down the number of false positives: to avoid neediess anxiety, and to prevent
iatrogenic disease associated with the diagnostic process itself.
The data reported to date from the Kaiser-Permanente laboratories indicate that
automated multiphasic screening is both feasible and affordable. The quaetion is whether
it if; worthwhile. One answer is in terms of its effects on health. The Advisory Committee
on Automated Multiphasic Health Testing and Services (AMHTS) (1 15) states that much
of disease uncovered by testing will be chronic or not reversible; it will not yield a saving