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 effect estimates with a p-value between two groups are available?
Follow these steps:
- Determine whether the p-value corresponds to a z-distribution or t-distribution.
- Convert the p-value into a z-score or t-value using statistical tables.
- Calculate the SE of the mean difference between two groups using:
- Formula 21 (for z-score).
- Formula 22 (for t-value).
- Formula 21 (for z-score).
- Estimate the average SD for each group using Formula 20.
