What methods are used to analyse continuous outcomes in a meta-analysis?
Continuous outcomes in a meta-analysis are analysed using an inverse variance method for pooling weighted mean differences. Where the studies within a single meta-analysis have different scales of measurement, standardised mean differences are used. If standard deviations are not reported, the standard error can be calculated from the p values or 95% confidence intervals, and meta-analysis can be undertaken with the mean and standard error using the generic inverse variance method in Cochrane Review software. If statistical measures are not available, then the methods described in section 16.1.3 of the Cochrane Handbook (version 5.1.0, updated March 2011) are applied.