- OBJECTIVES: To assess whether health-care related economic evaluations labeled as "cost benefit analyses" (CBA) meet a contemporary definition of CBA methodology and to assess the prevalence of methods used for assigning monetary units to health outcomes. DATA SOURCES: Medline, Current Contents, and HSTAR databases and reference lists of review articles, 1991-1995. STUDY SELECTION: Economic analyses labeled as CBAs were included. Agreement on study selection was assessed. STUDY EVALUATION: CBA studies were classified according to standard definitions of economic analytical techniques. For those valuing health outcomes in monetary units (bona fide CBAs), the method of valuation was classified. RESULTS: 53% of 95 studies were reclassified as cost comparisons because health outcomes were not appraised. Among the 32% considered bona fide CBAs, the human capital approach was employed to value health states in monetary units in 70%. Contingent valuation methods were employed infrequently (13%). CONCLUSIONS: Studies labeled as CBAs in the health-care literature often offer only partial program evaluation. Decisions based only on resource costs are unlikely to improve efficiency in resource allocation. Among bona fide CBAs, the human capital approach was most commonly used to valuing health, despite its limitations. The results of health-care related CBAs should be interpreted with extreme caution.