Data synthesis
We will carry out statistical analysis using the Review Manager
software (RevMan 2008). We will use fixed-effect inverse variance
meta-analysis for combining data where trials are examining the
same intervention, and the trials’ populations and methods are
judged sufficiently similar. Where we suspect clinical or methodological
heterogeneity between studies sufficient to suggest that
treatment effects may differ between trials, we will use randomeffects
meta-analysis.
If substantial heterogeneity is identified in a fixed-effect meta-analysis
this will be noted and the analysis repeated using a randomeffects
method.