Mean and Mean difference are the two key statistical measures used in the statistical analysis. Both are essential for meta-analysis as well. Mean and Mean difference are used for the interpretation of a large set of values into a single number which explains the heterogeneity and variation among the individual values. However, one of a common challenge in meta-analysis is the unavailability of this data (mean and standard deviation).
Q & A Forum
Meta Analysis
Q: How can SD be estimated when only the standard error (SE) of the difference between two groups is available?

The standard deviation of within-group can be estimated using the mean standard deviation of both groups (Formula 20). This calculation will not affect the outcome of a meta-analysis, as pooled estimates value depends more on relative effects and mean differences rather than individual Standard Deviation of the groups.
