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 are funnel plots constructed in meta-analysis?

- Study precision is plotted on the vertical axis in funnel plot (reversed scale).
- Effect estimates (e.g., mean differences, odds ratios,) are plotted on the horizontal axis.
- If bias is present in a meta-analysis, asymmetry will be appear and missing studies on otther side of the chart.
- If bias is absent in a meta-analysis, a symmetrical inverted funnel shape will be obtained.
RevMan allows users to construct funnel plots with a triangular 95% confidence region, supporting findout potential bias.
Refernce:
Cochrane Handbook for Systematic Reviews of Interventions. (2011). 10.4.1 Funnel plots. The Cochrane Collaboration. Retrieved from
https://handbook-5-1.cochrane.org/chapter_10/10_4_1_funnel_plots.htm