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.

Related terms: CONSORT, Correlational Meta-Analysis, Effect size, <a href='/glossary/evidence-synthesis/'>Evidence synthesis</a>, Non-Intervention, Reproducible, and Open Systematic Reviews (NIRO-SR), PRISMA, Publication bias (File Drawer Problem), STROBE, <a href='/glossary/systematic-review/'>Systematic Review</a>

References: Borenstein et al. (2011), & Yeung et al. (2021)

Drafted and Reviewed by: Martin Vasilev, Siu Kit Yeung, Thomas Rhys Evans, Tamara Kalandadze, Charlotte R. Pennington, Mirela Zaneva

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