Assessing Heterogeneity Across Groups of Clinical Trials Based on Aggregate Data.

Meta-analyses are used to synthesize treatment information through application of statistical methods during all phases of clinical research and development, especially in the context of health technology assessment of the relative effectiveness between two treatments across trials as well as in drug reimbursement applications.1 The consistency of the treatment effect between groups of trials can be examined by applying heterogeneity testing for subgroup differences to aggregate trial data.2 There exists a wide variety of software for performing metaanalyses and testing subgroup heterogeneity, ranging from ready-to-use software like Review Manager (RevMan) from the Cochrane Collaboration3 to packages requiring statistical expert-knowledge inputs.4 Background