Issues in the design of future preventive medicine studies.

This paper discusses some of the design issues that are most important as cost-effectiveness analysis of preventive care advances from a novel application of economic reasoning to become an accepted aid in decision-making. In this new role, cost-effectiveness studies must be more consistent in approach and more standardized in assumptions than they have been in the past, so that valid comparisons can be made on the basis of studies done by different authors, or by the same authors at different times. The paper discusses the issues of the perspective of the study; the choice of discount rate; medical care costs in added years of life; measurement of the costs of institutionalization; measures of health effects that reflect changes in the quality as well as the quantity of life; and the proper place of estimates of earnings. Proposals are made in each of these areas to help standardize future studies.