Interpretation of "cost-effective" and soundness of economic evaluations in the pharmacy literature.

The varied interpretations of the term "cost-effective" in the pharmacy literature are discussed and the soundness of pharmacoeconomic analyses is assessed. Sixty-five studies concerning cost issues, which were published by six pharmacy journals from January 1985 to December 1990, were evaluated according to 10 methodological criteria. Two investigators independently reviewed each study and completed a data collection form; differences were discussed and resolved to ensure consistency of evaluation. In 36 (55%) of 65 articles, cost-effectiveness was misinterpreted as cost saving. Only 3 of the 10 criteria were fulfilled by 50% or more of the studies evaluated. Problem areas included the following: (1) identification of relevant costs and consequences of each strategy, (2) discounting--adjusting data to reflect the differential timing of costs and consequences, (3) incremental analysis--examining extra costs of a program relative to additional effects provided, and (4) sensitivity analysis. Many pharmacoeconomic studies inappropriately used the term "cost-effective" and inadequately addressed basic methodological components of an economic evaluation.