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 for the change score be estimated when baseline and post-intervention values are provided?
Introduction
Obtaining the Standard Deviation for change scores need correlation formula. But the change score mean can be estimated as the difference between baseline means and post-intervention. But Find research studies with the same outcome and intervention measurements.
- Assure the Standard Deviation and mean of post-intervention, baseline, and change scores are available in the study
- Calculate the correlation coefficient for both comparison groups and experimental group (Formulas 17 and 18).
- Calculate the total correlation coefficient by calculating average correlation coefficients for control and intervention group.
- Estimate the Standard Deviation of change score from post-intervention and baseline Standard Deviation values along with correlation co-efficient (Formula 19).