The promise and problems of meta-analysis.

Abstract

Meta-analysis has acquired a substantial following among both statisticians and clinicians. The technique was developed as a way to summarize the results of different research studies of related problems. Meta-analysis may be applied even when the studies are small and there is substantial variation in the specific issues studied, the research methods applied, the source and nature of the study subjects, and other factors that may have an important bearing on the findings. In this issue of the Journal, LeLorier et al.1 compare the findings of 12 large randomized, controlled trials with the results of meta-analyses of the same problems. . . .