Meta-analysis

Definition

A meta-analysis is a statistical synthesis of results from a series of studies examining the same phenomenon. A variety of meta-analytic approaches exist, including random or fixed effects models or meta-regressions, which allow for an examination of moderator effects. By aggregating data from multiple studies, a meta-analysis could provide a more precise estimate for a phenomenon (e.g. type of treatment) than individual studies. Results are usually visualized in a forest plot. Meta-analyses can also help examine heterogeneity across study results. Meta-analyses are often carried out in conjunction with systematic reviews and similarly require a systematic search and screening of studies. Publication bias is also commonly examined in the context of a meta-analysis and is typically visually presented via a funnel plot.