Hi, I am doing a meta-analysis and have the mean change for both placebo and intervention groups, including n in each group. Is there a way to calculate Mean Difference 95% CI or is this calculated in RevMan? I am just inputting data in Excel right now.
Any help is greatly appreciated.
Thank you!
Perfect! You can directly apply the following formula, under the assumption of quasi-normal distribution of your data:
https://www.scribbr.com/statistics/confidence-interval/
Hi Igor Faddeenkov thank you but it's still difficult to understand how to work it out.
"Estimator of mean" +- 1.96 * sqrt("Estimator of mean" * (1 - "Estimator of mean") / "Sample size")
Formula to get upper resp. lower 95% CI
To calculate the Mean Difference (MD) with a 95% Confidence Interval (CI), here’s a simplified approach you can use based on the data you have:
1. Find the Mean Difference (MD): Subtract the mean of the placebo group from the mean of the intervention group.
2. Calculate the Standard Error of the Difference (SED): This accounts for how much the sample means are expected to vary. To get it, you’ll use the standard deviations (SDs) and sample sizes of both groups.
3. Get the 95% Confidence Interval:
- Multiply the SED by 1.96 (for a 95% confidence level).
Thanks
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