Meta-analysis
A Meta-analysis was originally a specialized kind of Systematic Review that uses quantitative methods of combining and synthesizing results of independent quantitative studies and provides summaries and conclusions which may be used to provide more precise effect of results. Meta-Analyses now include studies that use statistical methods to evaluate and synthesize results and may or may not be part of a systematic review.
SEARCH aims for exhaustive, comprehensive searching. May use funnel plot to assess completeness. requires either very sensitive search to retrieve all studies or separately conceived quantitative and qualitative strategies.
APPRAISAL includes quality assessment that may determine inclusion/exclusion and/or sensitivity analyses.
SYNTHESIS is graphical and tabular with narrative commentary.
ANALYSIS includes numerical analysis of measures of effect assuming absence of heterogeneity.
Source: A typology of reviews: an analysis of 14 review types and associated methodologies. Grant MJ & Booth A. Health information and Libraries Journal year: 2009 26(2):91 -108. doi: 10.1111/j.1471-1842.2009.00848.x.
Meta-Analysis Standards
- PRISMA for Meta-Analyseschecklist of essential reporting items to include when completing a network meta-analysis
Tools for MetaAnalyses
- Meta EssentialsMeta-Essentials is a free tool for meta-analysis. It facilitates the integration and synthesis of effect sizes from different studies. The tool consists of a set of workbooks designed for Microsoft Excel that, based on your input, automatically produces all the required statistics, tables, figures, and more.
- MetaforThe metafor package is a free and open-source add-on for conducting meta-analyses with the statistical software environment R. The package consists of a collection of functions that allow the user to calculate various effect size or outcome measures, fit equal-, fixed-, random-, and mixed-effects models to such data, carry out moderator and meta-regression analyses, and create various types of meta-analytical plots.
- MetaLightMetaLight is a software application designed to support the teaching and learning of meta-analysis. It is freely available and, as it uses the Silverlight browser plugin, can be run on just about any PC, thus facilitating its use in teaching environments such as PC labs.
- OpenMEEOpenMEE is open-source software for performing meta-analysis suited to the need of ecologist and evolutionary biologists. This program is made possible by the National Science Foundation (NSF).
- OpenMetaCompletely open-source, cross-platform software for advanced meta-analysis.
- PRISMA Extensin for Network Meta-AnbalysisThe PRISMA extension for network meta-analysis, or PRISMA-NMA, provides guidance for reporting systematic reviews comparing multiple treatments using direct and indirect evidence in network meta-analyses.