Meta‐analysis of prevalence: I 2 statistic and how to deal with heterogeneity

Abstract Over the last decade, there has been a 10‐fold increase in the number of published systematic reviews of prevalence. In meta‐analyses of prevalence, the summary estimate represents an average prevalence from included studies. This estimate is truly informative only if there is no substantial heterogeneity among the different contexts being pooled. In systematic reviews, heterogeneity is usually explored with I ‐squared statistic ( I 2 ), but this statistic does not directly inform us about the distribution of effects and frequently systematic reviewers and readers misinterpret this result. In a sample of 134 meta‐analyses of prevalence, the median I 2 was 96.9% (IQR 90.5–98.7). We observed larger I 2…