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Systematic Reviews: Meta-analyses

High-quality systematic reviews are designed to identify all relevant published and unpublished evidence and provide an unbiased synthesis of the findings.

What's the difference between a systematic review and a meta-analysis?





A systematic review summarizes the evidence from multiple studies in a narrative format.

A meta-analysis combines the data from the studies in a systematic review in order to increases the number of subjects and improves estimates of the size of the effect.


Systematically search for, appraise, and synthesize research evidence

Statistically combines the results of quantitative studies to provide a more precise effect of the results


Results are narrative with some tabular components

Results are graphical and tabular with narrative commentary


Makes recommendations for practice. Identifies areas where further research is needed.

Provides a numerical analysis of the measure of effect assuming absence of heterogeneity.

An Introduction to Meta-Analysis

What to include in a Meta-analysis

PRISMA Checklist:  a list of items to include in meta-analyses

MOOSE: a list of items to include in meta-analyses on observational studies

Guides on Conducting Meta-analyses

"Analysing data and undertaking meta-analyses" (Cochrane Handbook, Ch. 10) covers the principles and various methods for conducting meta-analyses for the main types of data encountered. 

Statistical algorithms in Review Manager  presents formulas such as odds ratio, risk ratio, tests for heterogeneity, confidence Intervals, etc.