Meta-analysis

Background resources on systematic reviews and meta-analysis — start here if you are new to the topic.

What is a systematic review / meta-analysis?

An introduction to systematic reviews and meta-analysis, and how the two terms relate.


Meta-analysis steps

The steps involved in conducting a meta-analysis, from defining the research area to publishing the results.


Assessing study quality and risk of bias

Risk-of-bias tools for different study designs, and how quality assessment feeds back into the analysis.


Methods and formulas

Effect sizes, heterogeneity, moderators, and publication bias — with the underlying formulas.


Statistical models: fixed-effect, random-effects, and multilevel

How each model combines effect sizes into a pooled estimate, including multilevel models for dependent effect sizes, and how to choose between them.


PRISMA flow diagram and reporting guideline

How to read the PRISMA flow diagram, what the checklist covers, and where it fits among other reporting guidelines.


Glossary

Definitions of the most important terms used in meta-analysis.


References

Books and articles on meta-analysis, organized by topic.


Specialized topics

Extensions of the standard process above, relevant only for specific kinds of data or research questions.

Network meta-analysis

Comparing three or more treatments at once by combining direct and indirect evidence, and the transitivity assumption it relies on.


Meta-analysis of single-case experimental designs

Overlap-based effect sizes (PND, NAP, Tau-U) for single-subject A-B designs, where standard effect sizes don't apply.