Investigating the Heterogeneity of “Study Twins”

Abstract

ABSTRACTMeta‐analyses are commonly performed based on random‐effects models, while in certain cases one might also argue in favor of a common‐effect model. One such case may be given by the example of two “study twins” that are performed according to a common (or at least very similar) protocol. Here we investigate the particular case of meta‐analysis of a pair of studies, for example, summarizing the results of two confirmatory clinical trials in phase III of a clinical development program. Thereby, we focus on the question of to what extent homogeneity or heterogeneity may be discernible and include an empirical investigation of published (“twin”) pairs of studies. A pair of estimates from two studies only provide very little evidence of homogeneity or heterogeneity of effects, and ad hoc decision criteria may often be misleading.