This paper examines eight published reviews each reporting results from several related
trials. Each review pools the results from the relevant trials in order to evaluate the efficacy of
a certain treatment for a specified medical condition. These reviews lack consistent
assessment of homogeneity of treatment effect before pooling. We discuss a random effects
approach to combining evidence from a series of experiments comparing two treatments.
This approach incorporates the heterogeneity of effects in the analysis of the overall …