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Cost-benefit concepts in health: Examination of some prevention efforts
PREVENTIVE
7,414-423 (1978)
MEDICINE
Cost-Benefit
Concepts in Health: Examination Some Prevention Efforts’
JUDITH
of
R. LAVE~ AND LESTER B. LAVE~
Department of Economics and Urban Affairs, School of Urban and Public Affairs, Department of Economics, Graduate School of Industrial Administration, Carnegie-Mellon University, Pittsburgh, Pennsylvania 15213
and
As expenditures on health continue to increase it becomes important to determine the effectiveness of health care programs. In this paper we outline an approach to evaluating health care programs with particular emphasis on preventive programs. We argue that the most important and most difficult step in the process is assessing the differential impact a measure has on health status. Some specific programs including environmental control, the search for healthful life-styles, and screening programs are briefly considered.
I. INTRODUCTION
A scholarly climber, perched on top of Mt. Everest, might answer the question of why he had climbed the mountain with: “Res ipso loquitur. The climb is a noble and heroic endeavor and the justification is self-evident.” Searching for methods to prevent cancer or detect it early are noble endeavors. However, “yes ipso loquituv” is not an adequate justification for allocating billions of dollars and large numbers of scarce biomedical researchers and physicians to programs with these aims. Five reasons for evaluating health programs are (in reverse order): (1) Many programs contain a statutory requirement for evaluation. (2) To exercise their oversight functions the Congress (generally through the GAO) and the Executive (generally through the planning and evaluation offices) request evaluations of programs. (3) Decision makers are continually forced to decide which programs get large budget increases and which are curtailed. If only superficial information is available, only superficial information can be used to make budget decisions, e.g., nobility of the program’s goal, persuasiveness of its administrator, or number of people employed. More importantly, physicians and consumers need good information to determine what kinds of care to provide and seek. (4) While the nation’s resources are large, they are finite. If resources are to be allocated to a particular preventive program, they must be shifted from other uses: To obtain the professionals and funds for a preventive care program, other ’ This paper is based on a presentation to the American Society of Preventive Oncology, February 4-5, 1977, New York. The work was supported by the National Center for Health Services Research under Grant 3 R01 HS01529. 2 Address requests for reprints to: Judith R. Lave, Ph.D., Associate Professor of Economics and Urban Affairs, School of Urban and Public Affairs, Carnegie-Mellon University, Pittsburgh, Pennsylvania 15213. ’ Professor and Head, Department of Economics, Graduate School of Industrial Administration, Carnegie-Mellon University. 414 0091-7435/78/0073-0414$02.00/O Copyright All
rights
0
1978 by Academic
of reproduction
in any
Press. form
Inc. reserved.
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preventive programs, acute care programs, or nonhealth activities must be reduced or curtailed. (5) Lying behind the four reasons just given is the desire to improve health. If the health of individuals is to be improved, we must evaluate health programs to determine whether they are fulfilling their goals, and then evaluate the goals to ensure that they are appropriate to improving health. II. A PRIMER ON EVALUATION
There are four basic steps involved in an evaluation. (i) List the effects of the program (both beneficial and negative effects); (ii) relate the effects quantitatively to the program. (iii) translate the effects into some single metric (this includes comparing inputs and outcomes both at present and over time), and (iv) compare the positive and negative effects of the program (10, 19). Consider screening for breast cancer. The first step involves listing the effects of the program. These will include: (a) the costs of convincing women to be screened; (b) the cost of transportation and the time devoted to the visit; (c) the cost of the professional people and the capital used in screening; (d) the cost of follow-up and the treatment of people who were found abnormal on the screen; (e) the cost of any deleterious (iatrogenic) effect of the screen, follow-up, and treatment; and (f) diminished morbidity and mortality and the lowered use of medical resources by women who had tumors found early and thus benefitted from early treatment. False positives and false negatives are both critical. (False positives increase the cost of the program; they occur not only because of quality control and inherent problems in the test, but also because of inherent variation in the population. A false negative may give a woman undue assurance, causing her to neglect symptoms such as lumps.) The second step involves relating the effects quantitatively to the program. In this example it means determining: (a) how the cost of convincing women to be screened is related to the proportion of the population sought; (b) what is the increase in iatrogenic disease due to screening; and (c) what is the increase in life expectancy and general health status due to screening, both as they vary with the frequency of screening (semiannually, annually, biennially, etc.) and with the type of screening (e.g., palpation versus mammography). The third step inyolves translation of the effects into comparable units-usually dollars. Some of these effects are easy to translate, i.e., the costs of screening and follow-up treatment. Other effects, such as the improvement in life expectancy and health status, are not easy to translate into dollars. Some evaluators would stop here, i.e., they would report the cost of achieving various outcomes (e.g., it costs $x dollars to gain an additional year of life expectancy for women aged 25-40 and $y dollars to gain an additional year of life expectancy for women aged 50-55). Other researchers have attempted to monetize the benefits, i.e., to put a dollar value on the gain in life expectancy. The fourth step is but an extension of the third. This step involves comparison of the benefits and costs of the program. III. PROBLEMS
IN EVALUATION:
Evaluation is not an easy process. Some specific problems are discussed below.
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1. Quantifying the Effects of a Program The most difficult and important step in an evaluation is quantifying the effects of a program. For example, does a particular screening program and associated treatment program detect breast cancer at an early stage? What are the iatrogenic effects and latency periods? Does the program result, on balance, in improved health status, increased life expectancy, and reduction of deaths due to breast cancer? Answering these questions is difficult. Women who come in to be screened are likely to be different from those who do not; thus, simple analyses give biased results. Early detection of breast cancer would appear to give better j-year survival rates, even if the treatment were of no efficacy. The iatrogenic diseases might have a long latency period. But even answering these questions isn’t enough, since the frequency of screening, nature of screening, and treatment process must all be assessed in order to determine the best program. For example, a particular screening program might be found to be ineffective or prohibitively costly, but modifying the program to screen only a high risk population might reverse the conclusion. The difficulty of answering these questions and the painstaking work required are inherent in epidemiology. 2. The Value of Health To some it is evident that health is priceless and that we cannot value it. [For discussion see Refs. (3, 16, 36)]. However, we all act as if there are trade-offs between health and other goods as we allocate our resources, privately and publicly. Some of us choose to engage in risky occupations, to participate in risky sports, or to drive cars less safe than others we might buy. Although a large literature deals with the value of health (1, 3, 7, 8, 35,43), we do not have good dollar estimates. For some restricted purposes the present value of wages and medical costs may be a good approximation. 3. The Ethics of Data Collection An inherent problem in evaluating any preventive program is the lack of data. The clinical trial is the classic research design, but in practice there are often problems in implementing and sustaining a trial. It is difficult to subjugate a physician’s obligation to an individual patient to his obligation to knowledge. Information on which to base a decision must be gained elsewhere (37). However, knowledge which can come only from clinical trials is essential. Current medical practice contains many treatments of preference for which there is no more than a shred of evidence of superiority over alternative treatments. The recent evaluations of radical versus simple mastectomy as treatment for breast cancer indicate that survival rates do not differ. However, radical mastectomy not only mutilates women more but also costs significantly more (25). Worse, there are treatments of preference later shown to be ineffective or even pernicious, such as irradiation of the thyroid glands of children and putting premature babies into pure oxygen atmospheres. There are many examples of decisions based on limited evidence leading to treatment that harmed rather than helped patients. For example, some experts have argued that the incidence of breast cancer in young women (not otherwise identified as high risk) is so low, and the additional detection power of mammography sufficiently small, that screening of young women ends up sav-
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ing fewer lives than are destroyed by the screening test (through cancer caused by radiation from the test) (5). A diagnostic tool useful for women with specific symptoms or for screening high risk women may be pernicious when used for screening low risk women. 4. Other
(i) Evaluations are often filled with fallacies. One common fallacy is that wages paid to health or construction workers are benefits; thus, the increased employment due to a new program is sometimes counted as a benefit, not a cost. Wages should be counted as a cost, since many programs compete for funds; because we cannot do all projects, we should do first those with the greatest benefit relative to cost. (ii) One must distinguish between a program’s potential effectiveness and its probable effectiveness when widely implemented. Programs which are effective in clinical settings (or other controlled environments) with highly trained personnel may be less effective in the field. Consider potable water, sanitation, and control of hypertension. The full potential of improved water quality and sanitation was achieved because their success did not depend on individual participation. In contrast, the need for an individual with hypertension to take his medication and watch his diet has impeded the effectiveness of known remedies; a potentially efficacious system is rendered partially ineffective in practice. (iii) The effectiveness of a program is the product of the efficacy of a behavior change and the probability of getting people to change their behavior. At the National Conference on Prevention in June 1975, all agreed that, if people changed their habits to healthy life-styles that included exercise, good nutrition, less stress, and no smoking, they would be healthier. But this conclusion is interesting only insofar as people can be convinced to change their habits. It is a logical fallacy to jump from a conclusion that health education could be effective to the conclusion that it will be effective [but see Refs. (13, 33)]. IV. IS EVALUATION USEFUL? The list of problems above appears formidable, and we must recognize the fact that many decisions must be made on the basis of inadequate information. Although conclusive information may be unavailable, the public health official and physician (and the patient) can benefit from evaluation. Listing the effects of the decision and attempting to relate each to the scope of the program are valuable, even when one can only guess at the facts. Many flights of fancy are grounded, although data are unavailable, by correctly formulating the problem in terms of inputs, outcomes, the opportunity costs of the resources, and alternative risks. The difficulties in evaluation should be viewed not as an apology that we can do no better, but rather as a goad to improve this technique and to apply it more widely. We already spend over 130billion dollars on health care every year. There is no substitute for posing the questions correctly and for getting the best possible answers, even if all of the questions cannot be answered satisfactorily. Systematic analysis is better than visceral reactions.
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V. SOME RESULTS
We co-chaired a task force on the Economic Impact of Preventive Medicine which reported to the National Conference on Prevention in June 1975 (21). With the help of an excellent committee we went through much of the literature evaluating preventive health care programs. [For other reviews, see Refs. (17, 28 and 29)]. Below we summarize some of our results. 1. Overall Impression In the literature, there were few analyses in which the four proposed steps above had been followed. The major exceptions were the evaluations of immunization programs and the evaluation of the multiphasic program at Kaiser. (In both these studies, the benefits were monetized at market wage rates .) Most analyses stopped at trying to ascertain whether the proposed intervention had an effect, i.e., a differential impact on the health status of the population at risk. The difficulty that investigators had in quantifying this association reinforces our argument that the second step of the evaluation is the most difficult and most important. The costs of the programs often were not identified. In addition, it was rare that alternative levels of the intervention had been applied so that one could estimate the “doseresponse” curve. (In some cases alternative levels of the intervention, i.e., screening for PKU, may not be relevant; in other cases, i.e., screening for cancer of the cervix, they surely are.) 2. Environmental Control Although we did not review any of the work on the efficacy of the traditional public health kinds of measures, we have no doubt that they were effective. Indeed, in a cross-national comparison Stewart (42) has found that funds allocated to public health account for major variations in mortality rates. Air pollution and water pollution come closest in concept to the environmental problems faced at the turn of the century. A good deal of evidence has been accumulated that a lowering of air pollution from current levels would lead to a significant decrease in morbidity and mortality in urban areas (2, 12, 22, 23, 31, 41). The epidemiologic results have been reinforced by results from toxicology and occupational medicine. Using current estimates of the costs of abating air pollution (and monetizing the health benefits at wage rates), it is estimated that the benefits are considerably greater than costs for enforcing EPA’s particulate and sulfur oxide standards. Abating air pollution is a high priority program. Abatement of water pollution is a lower priority program since people need not expose themselves to polluted water (31). In contrast to air pollution, our exposure to the adverse effects of water pollution is lessened by modern water treatment plants in urban water supply systems. However, even here there is growing evidence that carcinogenic substances are present in many urban water systems. This situation warrants monitoring. 3. Healthful Life-styles A growing body of literature suggests that individuals who have healthful habits
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have lower morbidity and mortality rates than individuals who smoke, drink excessively, are over- or underweight, have poor nutrition habits, get too little sleep, get too little exercise, or live tense lives (6, 29, 30, 32). Of these health habits the relationship between smoking and health is most clearly established, particularly the relationship between smoking and the incidence of certain types of cancer (44, 46). The evidence suggests that a change in health habits could be effective in improving the health of the nation (13,33). It is, however, a big step from identifying a problem to designing a program for its resolution. We need only point out that the adverse effects of smoking on health have been known for some time, and yet there is a trend toward increased smoking among young people-in particular adolescent girls (45). While we would argue that much work ought to go into innovative experimental programs, we believe such programs ought to be carefully evaluated before they are implemented on a large scale. 4. Immunization Immunizing vaccines have been developed for a number of communicable diseases. Benefit -cost analyses of the immunization programs have been conducted primarily at the Center for Disease Control (CDC) (4,47). To assessthe immunization programs, the efficacy of the vaccine, the cost of administering the vaccine, the benefits from the reduced incidence of the disease, and the cost of side effects were all considered. If one uses wage rates to monetize the health benefits, the measles program appears to have a benefit-cost ratio of about 10 to 1. The benefit-cost ratio for mumps is si nificantly lower (because the complications of the disease are rarer), and the C73 C concludes that the benefits of a mumps vaccine would be less than costs if given by itself, but benefits would exceed costs if the vaccine were given as part of a regular examination or in conjunction with other vaccines. Rubella has not been evaluated, but there is evidence that the economic cost of the rubella epidemic of 1964.- 1965ran to $1.5 billion. Clearly the benefit-cost ratio of a combined rubella, measles, mumps vaccine is very high, as the costs are little higher than for one vaccine alone. Swine flu and smallpox provide an interesting contrast. While smallpox vaccination is effective, its side effects are important and the underlying probability that a person will get smallpox is almost negligible. Evaluation of the program led to the Public Health Service’s recommending a discontinuation of routine vaccination for children. During the 1976-1977 flu season, there was doubt as to the likelihood of a swine flu epidemic, the question of virulence of the virus, and the question of effectiveness of the vaccine if there were an epidemic. When serious side effects became evident, the program was cancelled. Thus the results of evaluating any flu vaccine depend critically on assumptions about the probability of an epidemic, the efficacy of the vaccine, and the likelihood of side effects. 5. Screening for Disease Screening is an example of secondary prevention. The basic purpose of screening is to detect the presence of a disease before the onset of symptoms, to initiate early treatment, and thus to influence subsequent morbidity and mortality patterns. Screening for PKU was made almost universal in the United States before
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analyses were done to justify the program. While there is evidence that the effectiveness of the screening programs can be enhanced (18, 39), and while there are substantial difficulties with the evaluations to date, there is agreement that the benefits of screening for PKU exceed its costs (24, 40). A wide range of estimates have been published concerning the benefits of screening for cancer of the cervix utero (14, 17, 34). Evidence on the efftcacy of screening is confounded by the fact that mortality due to cervical cancer has been decreasing in the unscreened as well as the screened population and because of uncertainty about the natural course of the disease. Furthermore, those women who are more likely to be examined on a regular basis, middle and upper income women, normally have a lower rate of cervical cancer than do lower income women. While recent Canadian data indicate that screening is effective (37), the frequency with which screening should take place, even if it is efficacious, is as yet undetermined. The evidence of the efficacy of screening for breast cancer is much better than that for cervical cancer (5,37). The basic data on the effects of screening for breast cancer are from a large scale clinical trial on women aged 40 to 64 carried out at Health Insurance Program in New York (37, 38). The data from that program indicate that the screening program did not affect the outcome (survival and mortality) of women in the age group 40-49. The program did, however, lead to a significant decrease in the mortality rates of women between 50 and 59 years of age. It also seemed to have an effect on women between 60 and 64 years of age. The cost of the program was not indicated. A similar trial has not been conducted for younger women. One cost-benefit analysis of mammography screening done by the National Cancer Institute is reported by Kristein (20). The NC1 estimated, based on evidence from 27 Demonstration Units, that 20% more breast cancers were discovered in the localized stage as a result of screening. It then estimated that, at a cost of $40.00 per mammogram the minimum annual cost per life prolonged is $240,000 (24,000 per year of life saved) for women in the age group 55-64. These figures, however, overestimate the benefits of screening since mammography is likely to induce some cancers. The best data we have on the efficacy of multiphasic screening come from a large scale clinical trial carried out at Kaiser (9). The results of that study are ambiguous. There were statistically fewer deaths from two postponable causes in the screened population (cancer of the colon and rectum; and hypertension-hypertensive cardiovascular disease). For men aged 45-54 at entry, morbidity and mortality rates were lower for members of the screened population, whereas, for women aged 45-54 at entry, the rates were higher. For other age groups, no differential morbidity or mortality rates were ascertained between the screened and unscreened populations. Thus looking at screening programs we see that one program, PKU, is estimated to have a benefit-cost ratio greater than 1; two programs, screening for cancer of the breast in high risk populations and screening for cancer of the cervix appear to be effective in the sense that members of the screened populations have lower mortality rates; and one (multiphasic screening) has ambiguous effects on
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future morbidity and mortality rates. We should stress that the effects we have been considering are differential effects on measurable health status. The positive benefits to be derived from knowing one is healthy at a particular period of time are not included. V. CONCLUSIONS
We can do no better than to quote the conclusions of our task force report. 1. Benefit -cost or cost -effectiveness analysis cannot be used as the sole criterion for decision making concerning health care programs, since these tools are difticult to apply in practice and since issues such as income distribution effects are not usually encompassed. 2. Health care programs must be evaluated if we are to realize the potential of medical care, prevent iatrogenic disease, and contain cost; in particular, cost effectiveness can be applied and is an invaluable aid in deciding which programs should be required, financed through public funds, encouraged, or perhaps even prohibited. The results of such evaluations are of as much interest to consumers who must decide how much to spend on preventive services as they are to public decision makers. 3. Therapeutic and preventive health care programs ought to be evaluated by equally critical techniques and judged by the same criteria. 4. Research and development must be accomplished to determine the efficacy and costs of proposed programs; in particular, large scale clinical trials are one of the most important techniques for developing evidence on efftcacy. 5. General health status is the primary measure of efficacy; thus, improved measures of health status must be developed and applied. REFERENCES 1. Acton, J. P. “Evaluating Public Programs to Save Lives: The Case of Heart Attacks,” (R-950RC). The Rand Corporation, Santa Monica, California, 1973. 2. Amdur, M. Toxicological guidelines for research on sulfur oxides and particulates, in “Proceedings of the Fourth Symposium on Statistics and the Environment,” pp. 48-55. American Statistical Association, Washington, DC., 1976. 3. American Sociological Association, Medical Sociology Section. Issues in promoting health 1977. Committee Reports of the Medical Sociology Section. Me&cd Cure 15 (May Supplement, 1977). 4. Axnick, W., Shawall, S., and Witte, J. Benefits due to immunization against measles. Pub. Health Rep. 84, 673-680 (August 1969). 5. Bailar, J. C. Screening for early breast cancer: Pros and cons. Cancer 39, 2783-2795 (1977). 6. Belloc, N. Relationship of health practices and mortality. Prev. Med. 2, 67-81 (1973). 7. Berg, R. Establishing the values of various conditions of life for a health status index, in “Health Status Indexes” (R. Berg, Ed.), pp. 120- 134. Hospital Research and Educational Trust, Chicago, 1973. 8. Cooper, B. S., and Rice, D. P. The economic cost of illness revisited. Sot. Security Bull. 39, 21-36 (1976). 9. Dales, L. G., Friedman, G. D., Ramcharan, S., Siegelaub, A. B., Campbell, B. A., Feldman, R., and Collen, M. F., Multiphasic checkup evaluation study. 3. Outpatient clinic utilization, hospitalization, and mortality experience after seven years. Prev. Med. 2, 221-235 (1973). 10. Dasgupta, A., and Pearce, D. “Cost-Benefit Analysis.” Macmillan, New York, 1972. 11. Dublin, L., and Lotka, A. “The Money Value of a Man.” Ronald Press, New York, 1930. 12. Environmental Protection Agency. “The Economics of Clean Air.” Government Printing Office, Washington, D.C., 1972.
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13. Farquhar, J. W., Maccoby, N., Wood, P. D., Alexander, J. K., Breitrose, H., Brown, B. W. Jr., Haskell, W. L., McAlister, A. L., Meyer, A. J., Nash, J. D., and Stern, M. P. Community education for cardiovascular health. Lancer 1, 1192- 1195 (1977). 14. Guzick, D. S. Efficacy of Screening for Cervical Cancer: A review. Amer. J. Pub. Healfh 68, 125-134 (1978). 15. Hill, A. The environment and disease: Association or causation? Proc. Roy. Sot. Med. Sect. Occup. Med. 58, 295-300
(1965).
16. Hirshleifer, J., Bergstrom, T., and Rapoport, E. “Applying Cost Benefit Concepts to Projects UCLA, School of Engineering and Applied Science, Which Alter Human Mortality.” Noyember 1974. 17. Holland, W. W. Taking stock. Lancer 2, 1494-1497 (1974). 18. Holtzman, W. Screening for phenylketonuria and its problems, in “International Congress Series No. 310, Proceedings of the Fourth International Conference,” Vienna, 1973. 19. Klarman, H. E. Application of cost-benefit analysis to the health services and the special case of technologic innovation. Znr. J. Health Serv. 4, 325-352 (1974). 20. Kristein, M. Economic issues in prevention. Prev. Med. 6, 252-264 (1977). 21. Lave, J. R., Lave, L. B., Acton, J., Berg, R. L., Klarman, H. E., Rice, D. P., and Rothschild, M. Economic impact of preventive medicine, in “Preventive Medicine USA”, pp. 675-714. Prodist, New York, 1975. 22. Lave, L., and Seskin, E. Air pollution and human health Science 169, 723-733 (1970). 23. Lave, L., and Seskin, E. “Air Pollution and Human Health.” The Johns Hopkins University Press, Baltimore, 1977. 24. Levy, H. Letter to the Editor. New Engl. J. Med. 292, 1246 (1975). 25. McPherson, K., and Fox, M. S. Treatment of breast cancer, in “Costs, Risks, and Benefits of Surgery” (J. Bunker, B. Barnes, and F. Mosteller, Eds.), pp. 308-322. Oxford University Press, New York, 1977. 26. Mishan, E. J. Evaluation of life and limb: A theoretical approach. J. Political Econ. 79, 687-705 (1971). 27. National Academy of Sciences. “Geochemistry and the Environment.” Washington, D.C., 1974. 28. New York Academy of Medicine. Prevention and Health Maintenance Revisited. The 1974 Annual Health Conference, The New York Academy of Medicine. Bull. N. Y. Acud. Med. 51, I-258 (1975). 29. Nightingale, E. O., Cureton, M., Kalmar, V., and Trudeau, M. “Perspectives on Health Promotion and Disease Prevention in the United States.” Institute of Medicine, National Academy of Sciences, January 1978. 30. Palmore, E. Health practices and illness among the aged. Gerontologisr 10, 313-316 (1970). 31. Peskin, H., and Seskin, E. “Cost-Benefit Analysis and Water Pollution Policy.” The Urban Institute, Washington, D.C., 1975. 32. “Preventive Medicine U.S.A.” (sponsored by The John E. Fogarty International Center and The American College of Preventive Medicine). Prodist, New York, 1976. 33. Puska, P., and Mustaniemi, H. Incidence and presentation of myocardial infarction in North Kareha, Finland. Acru Med. Scund. 197, 21I-216 (1975). 34. Randall, K. J. Cancer screening by cytology. Luncet 2, 1303- 1304 (1974). 35. Rice, D. “Estimating the Cost of Illness.” Public Health Service Publication 947-6. Washington, D.C., May 1966. 36. Schelling, T. The life you save may be your own, in “Problems in Public Expenditure Analyses” (S. Chase, Ed.), pp. 127-176. The Brookings Institution, Washington, D.C., 1968. 37. Shapiro, S. Measuring the effectiveness of prevention: II. Milbunk Mem. Fldnd Quurr. 55, 291-306 (1977). 38. Shapiro, S., Strax, P., Venet, L., and Venet, W. Changes in 5-year breast cancer mortality in a breast cancer screening program, in “Seventh National Cancer Conference Proceedings,” pp. 663-678. J. B. Lippincott, Philadelphia, 1973. 39. Starfield, B., and Hohzman, N. A. A comparison of effectiveness of screening forphenylketonuria in the United States, United Kingdom and Ireland. New Engl. J. Med. 293, 118-121 (1975). 40. Steiner, K. C., and Smith, H. A. Application of cost benefit analysis to a PKU screening program. Inquiry 10, 34-40 (1973).
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41. Stem, A. “Air Pollution.” Academic Press, New York, 1968. 42. Stewart, C. Allocation of resources to health. J. Hum. Resources 6, 103- 122(1971). 43. Thaler, R., and Rosen, S. “The Value of Saving a Life: Evidence from the Labor Market.” Working Paper, Department of Economics, University of Rochester, 1973. 44. U.S. Department of Health, Education, and Welfare. “The Health Consequences of Smoking. A Report to the Surgeon General”. DHEW Publication No. (HSM) 72-7516, Washington, D.C., 1972. 45. U.S. Department of Health, Education, and Welfare, National Institutes of Health. “Teenage Smoking. National Patterns of Cigarette Smoking, Ages 12through 18, 1972and 1974.” DHEW Publication No. (NIH) 76-931, Washington, D.C., 1976. 46. U.S. Department of Health, Education, and Welfare, Public Health Service. “Smoking and Health: Report of the Advisory Committee to the Surgeon General of the Public Health Service.” Public Health Service Publication No. 1103, Washington, D.C., 1964. 47. Witte, J. J. Recent advances in public health. Immunization. Amer. J. Publ. Health 64, 939-944 (1974).
7,414-423 (1978)
MEDICINE
Cost-Benefit
Concepts in Health: Examination Some Prevention Efforts’
JUDITH
of
R. LAVE~ AND LESTER B. LAVE~
Department of Economics and Urban Affairs, School of Urban and Public Affairs, Department of Economics, Graduate School of Industrial Administration, Carnegie-Mellon University, Pittsburgh, Pennsylvania 15213
and
As expenditures on health continue to increase it becomes important to determine the effectiveness of health care programs. In this paper we outline an approach to evaluating health care programs with particular emphasis on preventive programs. We argue that the most important and most difficult step in the process is assessing the differential impact a measure has on health status. Some specific programs including environmental control, the search for healthful life-styles, and screening programs are briefly considered.
I. INTRODUCTION
A scholarly climber, perched on top of Mt. Everest, might answer the question of why he had climbed the mountain with: “Res ipso loquitur. The climb is a noble and heroic endeavor and the justification is self-evident.” Searching for methods to prevent cancer or detect it early are noble endeavors. However, “yes ipso loquituv” is not an adequate justification for allocating billions of dollars and large numbers of scarce biomedical researchers and physicians to programs with these aims. Five reasons for evaluating health programs are (in reverse order): (1) Many programs contain a statutory requirement for evaluation. (2) To exercise their oversight functions the Congress (generally through the GAO) and the Executive (generally through the planning and evaluation offices) request evaluations of programs. (3) Decision makers are continually forced to decide which programs get large budget increases and which are curtailed. If only superficial information is available, only superficial information can be used to make budget decisions, e.g., nobility of the program’s goal, persuasiveness of its administrator, or number of people employed. More importantly, physicians and consumers need good information to determine what kinds of care to provide and seek. (4) While the nation’s resources are large, they are finite. If resources are to be allocated to a particular preventive program, they must be shifted from other uses: To obtain the professionals and funds for a preventive care program, other ’ This paper is based on a presentation to the American Society of Preventive Oncology, February 4-5, 1977, New York. The work was supported by the National Center for Health Services Research under Grant 3 R01 HS01529. 2 Address requests for reprints to: Judith R. Lave, Ph.D., Associate Professor of Economics and Urban Affairs, School of Urban and Public Affairs, Carnegie-Mellon University, Pittsburgh, Pennsylvania 15213. ’ Professor and Head, Department of Economics, Graduate School of Industrial Administration, Carnegie-Mellon University. 414 0091-7435/78/0073-0414$02.00/O Copyright All
rights
0
1978 by Academic
of reproduction
in any
Press. form
Inc. reserved.
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preventive programs, acute care programs, or nonhealth activities must be reduced or curtailed. (5) Lying behind the four reasons just given is the desire to improve health. If the health of individuals is to be improved, we must evaluate health programs to determine whether they are fulfilling their goals, and then evaluate the goals to ensure that they are appropriate to improving health. II. A PRIMER ON EVALUATION
There are four basic steps involved in an evaluation. (i) List the effects of the program (both beneficial and negative effects); (ii) relate the effects quantitatively to the program. (iii) translate the effects into some single metric (this includes comparing inputs and outcomes both at present and over time), and (iv) compare the positive and negative effects of the program (10, 19). Consider screening for breast cancer. The first step involves listing the effects of the program. These will include: (a) the costs of convincing women to be screened; (b) the cost of transportation and the time devoted to the visit; (c) the cost of the professional people and the capital used in screening; (d) the cost of follow-up and the treatment of people who were found abnormal on the screen; (e) the cost of any deleterious (iatrogenic) effect of the screen, follow-up, and treatment; and (f) diminished morbidity and mortality and the lowered use of medical resources by women who had tumors found early and thus benefitted from early treatment. False positives and false negatives are both critical. (False positives increase the cost of the program; they occur not only because of quality control and inherent problems in the test, but also because of inherent variation in the population. A false negative may give a woman undue assurance, causing her to neglect symptoms such as lumps.) The second step involves relating the effects quantitatively to the program. In this example it means determining: (a) how the cost of convincing women to be screened is related to the proportion of the population sought; (b) what is the increase in iatrogenic disease due to screening; and (c) what is the increase in life expectancy and general health status due to screening, both as they vary with the frequency of screening (semiannually, annually, biennially, etc.) and with the type of screening (e.g., palpation versus mammography). The third step inyolves translation of the effects into comparable units-usually dollars. Some of these effects are easy to translate, i.e., the costs of screening and follow-up treatment. Other effects, such as the improvement in life expectancy and health status, are not easy to translate into dollars. Some evaluators would stop here, i.e., they would report the cost of achieving various outcomes (e.g., it costs $x dollars to gain an additional year of life expectancy for women aged 25-40 and $y dollars to gain an additional year of life expectancy for women aged 50-55). Other researchers have attempted to monetize the benefits, i.e., to put a dollar value on the gain in life expectancy. The fourth step is but an extension of the third. This step involves comparison of the benefits and costs of the program. III. PROBLEMS
IN EVALUATION:
Evaluation is not an easy process. Some specific problems are discussed below.
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1. Quantifying the Effects of a Program The most difficult and important step in an evaluation is quantifying the effects of a program. For example, does a particular screening program and associated treatment program detect breast cancer at an early stage? What are the iatrogenic effects and latency periods? Does the program result, on balance, in improved health status, increased life expectancy, and reduction of deaths due to breast cancer? Answering these questions is difficult. Women who come in to be screened are likely to be different from those who do not; thus, simple analyses give biased results. Early detection of breast cancer would appear to give better j-year survival rates, even if the treatment were of no efficacy. The iatrogenic diseases might have a long latency period. But even answering these questions isn’t enough, since the frequency of screening, nature of screening, and treatment process must all be assessed in order to determine the best program. For example, a particular screening program might be found to be ineffective or prohibitively costly, but modifying the program to screen only a high risk population might reverse the conclusion. The difficulty of answering these questions and the painstaking work required are inherent in epidemiology. 2. The Value of Health To some it is evident that health is priceless and that we cannot value it. [For discussion see Refs. (3, 16, 36)]. However, we all act as if there are trade-offs between health and other goods as we allocate our resources, privately and publicly. Some of us choose to engage in risky occupations, to participate in risky sports, or to drive cars less safe than others we might buy. Although a large literature deals with the value of health (1, 3, 7, 8, 35,43), we do not have good dollar estimates. For some restricted purposes the present value of wages and medical costs may be a good approximation. 3. The Ethics of Data Collection An inherent problem in evaluating any preventive program is the lack of data. The clinical trial is the classic research design, but in practice there are often problems in implementing and sustaining a trial. It is difficult to subjugate a physician’s obligation to an individual patient to his obligation to knowledge. Information on which to base a decision must be gained elsewhere (37). However, knowledge which can come only from clinical trials is essential. Current medical practice contains many treatments of preference for which there is no more than a shred of evidence of superiority over alternative treatments. The recent evaluations of radical versus simple mastectomy as treatment for breast cancer indicate that survival rates do not differ. However, radical mastectomy not only mutilates women more but also costs significantly more (25). Worse, there are treatments of preference later shown to be ineffective or even pernicious, such as irradiation of the thyroid glands of children and putting premature babies into pure oxygen atmospheres. There are many examples of decisions based on limited evidence leading to treatment that harmed rather than helped patients. For example, some experts have argued that the incidence of breast cancer in young women (not otherwise identified as high risk) is so low, and the additional detection power of mammography sufficiently small, that screening of young women ends up sav-
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ing fewer lives than are destroyed by the screening test (through cancer caused by radiation from the test) (5). A diagnostic tool useful for women with specific symptoms or for screening high risk women may be pernicious when used for screening low risk women. 4. Other
(i) Evaluations are often filled with fallacies. One common fallacy is that wages paid to health or construction workers are benefits; thus, the increased employment due to a new program is sometimes counted as a benefit, not a cost. Wages should be counted as a cost, since many programs compete for funds; because we cannot do all projects, we should do first those with the greatest benefit relative to cost. (ii) One must distinguish between a program’s potential effectiveness and its probable effectiveness when widely implemented. Programs which are effective in clinical settings (or other controlled environments) with highly trained personnel may be less effective in the field. Consider potable water, sanitation, and control of hypertension. The full potential of improved water quality and sanitation was achieved because their success did not depend on individual participation. In contrast, the need for an individual with hypertension to take his medication and watch his diet has impeded the effectiveness of known remedies; a potentially efficacious system is rendered partially ineffective in practice. (iii) The effectiveness of a program is the product of the efficacy of a behavior change and the probability of getting people to change their behavior. At the National Conference on Prevention in June 1975, all agreed that, if people changed their habits to healthy life-styles that included exercise, good nutrition, less stress, and no smoking, they would be healthier. But this conclusion is interesting only insofar as people can be convinced to change their habits. It is a logical fallacy to jump from a conclusion that health education could be effective to the conclusion that it will be effective [but see Refs. (13, 33)]. IV. IS EVALUATION USEFUL? The list of problems above appears formidable, and we must recognize the fact that many decisions must be made on the basis of inadequate information. Although conclusive information may be unavailable, the public health official and physician (and the patient) can benefit from evaluation. Listing the effects of the decision and attempting to relate each to the scope of the program are valuable, even when one can only guess at the facts. Many flights of fancy are grounded, although data are unavailable, by correctly formulating the problem in terms of inputs, outcomes, the opportunity costs of the resources, and alternative risks. The difficulties in evaluation should be viewed not as an apology that we can do no better, but rather as a goad to improve this technique and to apply it more widely. We already spend over 130billion dollars on health care every year. There is no substitute for posing the questions correctly and for getting the best possible answers, even if all of the questions cannot be answered satisfactorily. Systematic analysis is better than visceral reactions.
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V. SOME RESULTS
We co-chaired a task force on the Economic Impact of Preventive Medicine which reported to the National Conference on Prevention in June 1975 (21). With the help of an excellent committee we went through much of the literature evaluating preventive health care programs. [For other reviews, see Refs. (17, 28 and 29)]. Below we summarize some of our results. 1. Overall Impression In the literature, there were few analyses in which the four proposed steps above had been followed. The major exceptions were the evaluations of immunization programs and the evaluation of the multiphasic program at Kaiser. (In both these studies, the benefits were monetized at market wage rates .) Most analyses stopped at trying to ascertain whether the proposed intervention had an effect, i.e., a differential impact on the health status of the population at risk. The difficulty that investigators had in quantifying this association reinforces our argument that the second step of the evaluation is the most difficult and most important. The costs of the programs often were not identified. In addition, it was rare that alternative levels of the intervention had been applied so that one could estimate the “doseresponse” curve. (In some cases alternative levels of the intervention, i.e., screening for PKU, may not be relevant; in other cases, i.e., screening for cancer of the cervix, they surely are.) 2. Environmental Control Although we did not review any of the work on the efficacy of the traditional public health kinds of measures, we have no doubt that they were effective. Indeed, in a cross-national comparison Stewart (42) has found that funds allocated to public health account for major variations in mortality rates. Air pollution and water pollution come closest in concept to the environmental problems faced at the turn of the century. A good deal of evidence has been accumulated that a lowering of air pollution from current levels would lead to a significant decrease in morbidity and mortality in urban areas (2, 12, 22, 23, 31, 41). The epidemiologic results have been reinforced by results from toxicology and occupational medicine. Using current estimates of the costs of abating air pollution (and monetizing the health benefits at wage rates), it is estimated that the benefits are considerably greater than costs for enforcing EPA’s particulate and sulfur oxide standards. Abating air pollution is a high priority program. Abatement of water pollution is a lower priority program since people need not expose themselves to polluted water (31). In contrast to air pollution, our exposure to the adverse effects of water pollution is lessened by modern water treatment plants in urban water supply systems. However, even here there is growing evidence that carcinogenic substances are present in many urban water systems. This situation warrants monitoring. 3. Healthful Life-styles A growing body of literature suggests that individuals who have healthful habits
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have lower morbidity and mortality rates than individuals who smoke, drink excessively, are over- or underweight, have poor nutrition habits, get too little sleep, get too little exercise, or live tense lives (6, 29, 30, 32). Of these health habits the relationship between smoking and health is most clearly established, particularly the relationship between smoking and the incidence of certain types of cancer (44, 46). The evidence suggests that a change in health habits could be effective in improving the health of the nation (13,33). It is, however, a big step from identifying a problem to designing a program for its resolution. We need only point out that the adverse effects of smoking on health have been known for some time, and yet there is a trend toward increased smoking among young people-in particular adolescent girls (45). While we would argue that much work ought to go into innovative experimental programs, we believe such programs ought to be carefully evaluated before they are implemented on a large scale. 4. Immunization Immunizing vaccines have been developed for a number of communicable diseases. Benefit -cost analyses of the immunization programs have been conducted primarily at the Center for Disease Control (CDC) (4,47). To assessthe immunization programs, the efficacy of the vaccine, the cost of administering the vaccine, the benefits from the reduced incidence of the disease, and the cost of side effects were all considered. If one uses wage rates to monetize the health benefits, the measles program appears to have a benefit-cost ratio of about 10 to 1. The benefit-cost ratio for mumps is si nificantly lower (because the complications of the disease are rarer), and the C73 C concludes that the benefits of a mumps vaccine would be less than costs if given by itself, but benefits would exceed costs if the vaccine were given as part of a regular examination or in conjunction with other vaccines. Rubella has not been evaluated, but there is evidence that the economic cost of the rubella epidemic of 1964.- 1965ran to $1.5 billion. Clearly the benefit-cost ratio of a combined rubella, measles, mumps vaccine is very high, as the costs are little higher than for one vaccine alone. Swine flu and smallpox provide an interesting contrast. While smallpox vaccination is effective, its side effects are important and the underlying probability that a person will get smallpox is almost negligible. Evaluation of the program led to the Public Health Service’s recommending a discontinuation of routine vaccination for children. During the 1976-1977 flu season, there was doubt as to the likelihood of a swine flu epidemic, the question of virulence of the virus, and the question of effectiveness of the vaccine if there were an epidemic. When serious side effects became evident, the program was cancelled. Thus the results of evaluating any flu vaccine depend critically on assumptions about the probability of an epidemic, the efficacy of the vaccine, and the likelihood of side effects. 5. Screening for Disease Screening is an example of secondary prevention. The basic purpose of screening is to detect the presence of a disease before the onset of symptoms, to initiate early treatment, and thus to influence subsequent morbidity and mortality patterns. Screening for PKU was made almost universal in the United States before
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analyses were done to justify the program. While there is evidence that the effectiveness of the screening programs can be enhanced (18, 39), and while there are substantial difficulties with the evaluations to date, there is agreement that the benefits of screening for PKU exceed its costs (24, 40). A wide range of estimates have been published concerning the benefits of screening for cancer of the cervix utero (14, 17, 34). Evidence on the efftcacy of screening is confounded by the fact that mortality due to cervical cancer has been decreasing in the unscreened as well as the screened population and because of uncertainty about the natural course of the disease. Furthermore, those women who are more likely to be examined on a regular basis, middle and upper income women, normally have a lower rate of cervical cancer than do lower income women. While recent Canadian data indicate that screening is effective (37), the frequency with which screening should take place, even if it is efficacious, is as yet undetermined. The evidence of the efficacy of screening for breast cancer is much better than that for cervical cancer (5,37). The basic data on the effects of screening for breast cancer are from a large scale clinical trial on women aged 40 to 64 carried out at Health Insurance Program in New York (37, 38). The data from that program indicate that the screening program did not affect the outcome (survival and mortality) of women in the age group 40-49. The program did, however, lead to a significant decrease in the mortality rates of women between 50 and 59 years of age. It also seemed to have an effect on women between 60 and 64 years of age. The cost of the program was not indicated. A similar trial has not been conducted for younger women. One cost-benefit analysis of mammography screening done by the National Cancer Institute is reported by Kristein (20). The NC1 estimated, based on evidence from 27 Demonstration Units, that 20% more breast cancers were discovered in the localized stage as a result of screening. It then estimated that, at a cost of $40.00 per mammogram the minimum annual cost per life prolonged is $240,000 (24,000 per year of life saved) for women in the age group 55-64. These figures, however, overestimate the benefits of screening since mammography is likely to induce some cancers. The best data we have on the efficacy of multiphasic screening come from a large scale clinical trial carried out at Kaiser (9). The results of that study are ambiguous. There were statistically fewer deaths from two postponable causes in the screened population (cancer of the colon and rectum; and hypertension-hypertensive cardiovascular disease). For men aged 45-54 at entry, morbidity and mortality rates were lower for members of the screened population, whereas, for women aged 45-54 at entry, the rates were higher. For other age groups, no differential morbidity or mortality rates were ascertained between the screened and unscreened populations. Thus looking at screening programs we see that one program, PKU, is estimated to have a benefit-cost ratio greater than 1; two programs, screening for cancer of the breast in high risk populations and screening for cancer of the cervix appear to be effective in the sense that members of the screened populations have lower mortality rates; and one (multiphasic screening) has ambiguous effects on
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future morbidity and mortality rates. We should stress that the effects we have been considering are differential effects on measurable health status. The positive benefits to be derived from knowing one is healthy at a particular period of time are not included. V. CONCLUSIONS
We can do no better than to quote the conclusions of our task force report. 1. Benefit -cost or cost -effectiveness analysis cannot be used as the sole criterion for decision making concerning health care programs, since these tools are difticult to apply in practice and since issues such as income distribution effects are not usually encompassed. 2. Health care programs must be evaluated if we are to realize the potential of medical care, prevent iatrogenic disease, and contain cost; in particular, cost effectiveness can be applied and is an invaluable aid in deciding which programs should be required, financed through public funds, encouraged, or perhaps even prohibited. The results of such evaluations are of as much interest to consumers who must decide how much to spend on preventive services as they are to public decision makers. 3. Therapeutic and preventive health care programs ought to be evaluated by equally critical techniques and judged by the same criteria. 4. Research and development must be accomplished to determine the efficacy and costs of proposed programs; in particular, large scale clinical trials are one of the most important techniques for developing evidence on efftcacy. 5. General health status is the primary measure of efficacy; thus, improved measures of health status must be developed and applied. REFERENCES 1. Acton, J. P. “Evaluating Public Programs to Save Lives: The Case of Heart Attacks,” (R-950RC). The Rand Corporation, Santa Monica, California, 1973. 2. Amdur, M. Toxicological guidelines for research on sulfur oxides and particulates, in “Proceedings of the Fourth Symposium on Statistics and the Environment,” pp. 48-55. American Statistical Association, Washington, DC., 1976. 3. American Sociological Association, Medical Sociology Section. Issues in promoting health 1977. Committee Reports of the Medical Sociology Section. Me&cd Cure 15 (May Supplement, 1977). 4. Axnick, W., Shawall, S., and Witte, J. Benefits due to immunization against measles. Pub. Health Rep. 84, 673-680 (August 1969). 5. Bailar, J. C. Screening for early breast cancer: Pros and cons. Cancer 39, 2783-2795 (1977). 6. Belloc, N. Relationship of health practices and mortality. Prev. Med. 2, 67-81 (1973). 7. Berg, R. Establishing the values of various conditions of life for a health status index, in “Health Status Indexes” (R. Berg, Ed.), pp. 120- 134. Hospital Research and Educational Trust, Chicago, 1973. 8. Cooper, B. S., and Rice, D. P. The economic cost of illness revisited. Sot. Security Bull. 39, 21-36 (1976). 9. Dales, L. G., Friedman, G. D., Ramcharan, S., Siegelaub, A. B., Campbell, B. A., Feldman, R., and Collen, M. F., Multiphasic checkup evaluation study. 3. Outpatient clinic utilization, hospitalization, and mortality experience after seven years. Prev. Med. 2, 221-235 (1973). 10. Dasgupta, A., and Pearce, D. “Cost-Benefit Analysis.” Macmillan, New York, 1972. 11. Dublin, L., and Lotka, A. “The Money Value of a Man.” Ronald Press, New York, 1930. 12. Environmental Protection Agency. “The Economics of Clean Air.” Government Printing Office, Washington, D.C., 1972.
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16. Hirshleifer, J., Bergstrom, T., and Rapoport, E. “Applying Cost Benefit Concepts to Projects UCLA, School of Engineering and Applied Science, Which Alter Human Mortality.” Noyember 1974. 17. Holland, W. W. Taking stock. Lancer 2, 1494-1497 (1974). 18. Holtzman, W. Screening for phenylketonuria and its problems, in “International Congress Series No. 310, Proceedings of the Fourth International Conference,” Vienna, 1973. 19. Klarman, H. E. Application of cost-benefit analysis to the health services and the special case of technologic innovation. Znr. J. Health Serv. 4, 325-352 (1974). 20. Kristein, M. Economic issues in prevention. Prev. Med. 6, 252-264 (1977). 21. Lave, J. R., Lave, L. B., Acton, J., Berg, R. L., Klarman, H. E., Rice, D. P., and Rothschild, M. Economic impact of preventive medicine, in “Preventive Medicine USA”, pp. 675-714. Prodist, New York, 1975. 22. Lave, L., and Seskin, E. Air pollution and human health Science 169, 723-733 (1970). 23. Lave, L., and Seskin, E. “Air Pollution and Human Health.” The Johns Hopkins University Press, Baltimore, 1977. 24. Levy, H. Letter to the Editor. New Engl. J. Med. 292, 1246 (1975). 25. McPherson, K., and Fox, M. S. Treatment of breast cancer, in “Costs, Risks, and Benefits of Surgery” (J. Bunker, B. Barnes, and F. Mosteller, Eds.), pp. 308-322. Oxford University Press, New York, 1977. 26. Mishan, E. J. Evaluation of life and limb: A theoretical approach. J. Political Econ. 79, 687-705 (1971). 27. National Academy of Sciences. “Geochemistry and the Environment.” Washington, D.C., 1974. 28. New York Academy of Medicine. Prevention and Health Maintenance Revisited. The 1974 Annual Health Conference, The New York Academy of Medicine. Bull. N. Y. Acud. Med. 51, I-258 (1975). 29. Nightingale, E. O., Cureton, M., Kalmar, V., and Trudeau, M. “Perspectives on Health Promotion and Disease Prevention in the United States.” Institute of Medicine, National Academy of Sciences, January 1978. 30. Palmore, E. Health practices and illness among the aged. Gerontologisr 10, 313-316 (1970). 31. Peskin, H., and Seskin, E. “Cost-Benefit Analysis and Water Pollution Policy.” The Urban Institute, Washington, D.C., 1975. 32. “Preventive Medicine U.S.A.” (sponsored by The John E. Fogarty International Center and The American College of Preventive Medicine). Prodist, New York, 1976. 33. Puska, P., and Mustaniemi, H. Incidence and presentation of myocardial infarction in North Kareha, Finland. Acru Med. Scund. 197, 21I-216 (1975). 34. Randall, K. J. Cancer screening by cytology. Luncet 2, 1303- 1304 (1974). 35. Rice, D. “Estimating the Cost of Illness.” Public Health Service Publication 947-6. Washington, D.C., May 1966. 36. Schelling, T. The life you save may be your own, in “Problems in Public Expenditure Analyses” (S. Chase, Ed.), pp. 127-176. The Brookings Institution, Washington, D.C., 1968. 37. Shapiro, S. Measuring the effectiveness of prevention: II. Milbunk Mem. Fldnd Quurr. 55, 291-306 (1977). 38. Shapiro, S., Strax, P., Venet, L., and Venet, W. Changes in 5-year breast cancer mortality in a breast cancer screening program, in “Seventh National Cancer Conference Proceedings,” pp. 663-678. J. B. Lippincott, Philadelphia, 1973. 39. Starfield, B., and Hohzman, N. A. A comparison of effectiveness of screening forphenylketonuria in the United States, United Kingdom and Ireland. New Engl. J. Med. 293, 118-121 (1975). 40. Steiner, K. C., and Smith, H. A. Application of cost benefit analysis to a PKU screening program. Inquiry 10, 34-40 (1973).
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41. Stem, A. “Air Pollution.” Academic Press, New York, 1968. 42. Stewart, C. Allocation of resources to health. J. Hum. Resources 6, 103- 122(1971). 43. Thaler, R., and Rosen, S. “The Value of Saving a Life: Evidence from the Labor Market.” Working Paper, Department of Economics, University of Rochester, 1973. 44. U.S. Department of Health, Education, and Welfare. “The Health Consequences of Smoking. A Report to the Surgeon General”. DHEW Publication No. (HSM) 72-7516, Washington, D.C., 1972. 45. U.S. Department of Health, Education, and Welfare, National Institutes of Health. “Teenage Smoking. National Patterns of Cigarette Smoking, Ages 12through 18, 1972and 1974.” DHEW Publication No. (NIH) 76-931, Washington, D.C., 1976. 46. U.S. Department of Health, Education, and Welfare, Public Health Service. “Smoking and Health: Report of the Advisory Committee to the Surgeon General of the Public Health Service.” Public Health Service Publication No. 1103, Washington, D.C., 1964. 47. Witte, J. J. Recent advances in public health. Immunization. Amer. J. Publ. Health 64, 939-944 (1974).