This workshop is given on behalf of the Statistical Methods Group.

Workshop type: Training.

Objective: To provide review authors with the knowledge to understand and investigate variability across studies in a meta-analysis, and to recognise the limitations of the methods available.

Summary:
This training workshop will address approaches to dealing with between-study variability, or heterogeneity, in the results of a series of clinical trials. We first will discuss some potential sources of between-study variability, and overview some methods for identifying whether heterogeneity poses a problem in a particular set of studies. We then will focus on issues related to dealing with study variability once it has been identified. In particular, we will discuss the decision whether or not to combine results; the choice between fixed and random-effects analyses; and the use of subgroup analyses (with a brief mention of meta-regression). Discussion will be supplemented with practical examples from the Cochrane Database of Systematic Reviews.

 [The workshop is part of a series of five workshops on meta-analysis, but does not require attendance at any of the others in the series.]

Intended audience: Review authors.

Technical level expected of participants: Basic.