Calculating statistical power for meta-analysis using metapower

Abstract

Meta-analysis is an inuential evidence synthesis technique that summarizes a body of research. Though impactful, meta-analyses fundamentally depend on the literature being suf-ciently large to generate meaningful conclusions. Power analysis plays an important role in determining the number of studies required to conduct a substantive meta-analysis. Despite this, power analysis is rarely conducted or reported in published meta-analyses. A signicant barrier to the widespread implementation of power analysis is the lack of available and accessible software for calculating statistical power for meta-analysis. In this paper, I provide an introduction to power analysis and present a practical tutorial for calculating statistical power using the R package metapower. The main functionality includes computing statistical power for summary effect sizes, tests of homogeneity, categorical moderator analysis, and subgroup analysis. This software is free, easy-to-use, and can be integrated into a continuous work ow with other meta-analysis packages in R.