Intervention effect estimates in cluster randomized versus individually randomized trials: a meta-epidemiological study

Cluster randomized trials (CRTs) and individually randomized trials (IRTs) are often pooled together in meta-analyses (MAs) of randomized trials. However, the potential systematic differences in intervention effect estimates between these two trial types has never been investigated. Therefore, we conducted a meta-epidemiological study comparing intervention effect estimates between CRTs and IRTs.All Cochrane MAs including at least one CRT and...