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 does the confidence level impact the width of the confidence interval?

Confidence intervals can be reported at different confidence levels (e.g., 90%, 95%, 99%):
- Higher confidence levels (e.g., 99%) → Wider CIs
- Lower confidence levels (e.g., 80%) → Narrower CIs
For example, if the odds ratio is 0.80, the confidence interval might be:
- 80% CI: 0.73 to 0.88
- 90% CI: 0.72 to 0.89
- 95% CI: 0.70 to 0.92
A higher confidence level provides greater certainty but less precision, while a lower confidence level provides more precise estimates but less certainty.
Reference:
Cochrane Handbook for Systematic Reviews of Interventions. (2011). 12.4.1 Confidence intervals. The Cochrane Collaboration. Retrieved from
https://handbook-5-1.cochrane.org/chapter_12/12_4_1_confidence_intervals.htm