Practice of Epidemiology Confidence Intervals for Heterogeneity Measures in Meta-analysis

Two methods of quantifying heterogeneity between studies in meta-analysis were studied. One method quanti-fied the proportion of the total variance of the effect estimate due to variation between studies (RI), and the other calibrated the variance between studies to the size of the effect itself through a between-study coefficient of varia-tion (CVB). Bootstrap and asymptotic confidence intervals for RI and CVB were derived and evaluated in an exten-sive simulation study that covered a wide range of scenarios likely to be encountered in practice. The best performance was given by asymptotic Wald confidence intervals developed for RI and CVB. The use of these het-erogeneity measures together with their confidence intervals was illustrated in 5 typical meta-analyses. A new user