The metafor Package

A Meta-Analysis Package for R

help

Documentation and Help

Below you can find some suggestions and tips on getting started with the metafor package and how to obtain help if you get stuck or have questions about the package.

Introduction Paper

A good starting place for those interested in using the metafor package is the following paper:

Viechtbauer, W. (2010). Conducting meta-analyses in R with the metafor package. Journal of Statistical Software, 36(3), 1–48.

You can download the paper here: https://doi.org/10.18637/jss.v036.i03. If the package is installed, you should also be able to open the paper with vignette("metafor").

The purpose of the paper is to provide a general overview of the metafor package and its capabilities (as of version 1.4-0). Not all of the functions and options are described (since a lot of additional functionality has been added to the package since the paper was published), but it should provide a useful introduction to the package.

Workshop Materials

At the beginning of 2022, I held an open workshop on meta-analysis with R (as part of the Evidence Synthesis & Meta-Analysis in R Conference). More details about the workshop can be found here. The materials from the workshop can be found here. The scripts from this workshop are heavily annotated and provide a pretty structured and thorough introduction to the use of the metafor package.

Meta-Analysis Books

If you are learning meta-analysis itself, you might be in the process of reading one or multiple books on meta-analysis. I have created R code to reproduce the examples and illustrations from various books on meta-analysis, which you can find here. Using these scripts while reading the contents of these books will also provide you with a pretty thorough introduction not only to meta-analysis itself, but also the use of R and the metafor package.

Reference Manual

The official reference manual (as a pdf) for the package can be found on CRAN. The manual describes all of the functions in the package together with their arguments and options. In R, you can also start browsing the documentation by typing help(metafor) (after loading the package with library(metafor)).

You can also read the entire documentation online at https://wviechtb.github.io/metafor/ (where it is nicely formatted, equations are shown correctly, and the output from all examples is provided).

A diagram showing the various functions in the metafor package (and how they are related to each other) can be found here. If the package is installed, you should also be able to open this diagram directly from R with the command vignette("diagram").