Solved – How to create a forest plot using the effect estimates (OR/RR and the confidence intervals) if no raw data is available

meta-analysis

I want to combine studies in a meta-analysis however I dont have raw data available to calculate original OR (95% CIs) from start. So I wonder if there is any way to create a forrest plot using this data only.

Best Answer

You can do this using the Generic Invariance Function in any of the major meta-analytic packages. Review Manager (RevMan is free from the Cochrane Collaboration) is a good example. You will need to input the effect estimate (e.g. Log Odds Ratio) and its Standard Error. If you are just given the OR and 95% confidence intervals then you need to back calculate the log of the OR, log of the Upper Confidence boundary (UCB), and log of the Lower Confidence Boundary (LCB). The Standard Error would be

(UCB - LCB)/(2 * 1.96).

Input that information into RevMan and you can then pool it.

Other statistical packages like Comprehensive Meta-Analysis can accept the OR and CIs without all the conversion, but they are not free.

Hope this helps.