I am looking at some data for the risk of mortality in patients undergoing treatment A vs treatment B and I am given the total number of patients in each treatment arm and the relative risk + confidence intervals of mortality. How would I go about finding the actual number of deaths in each treatment arm?
Here are the hard numbers:
Study 1 Adjusted total # of patients for treatment A: 8366 Adjusted total # of patients for treatment B: 10251 Adjusted RR for mortality: 0.72 (0.66-0.78) Study 1 Adjusted total # of patients for treatment A: 23113 Adjusted total # of patients for treatment B: 26819 Adjusted RR for mortality: 0.78 (0.72-0.83)
So I would like to compute the actual number of patients who died in each treatment arm for both studies 1 and 2.
Not sure if this helps but the paper states that:
adjusted survival curves were estimated with the use of the inverse-probability-weighting approach of Cole and Hernan. For each treatment group, the survival curves adjusted with the use of inverse probability weighting represent the expected rate of survival if the treatment of interest were applied to all study patients. Using estimated rates of survival among patients undergoing A and among those undergoing B, we calculated risk ratios at specific time points and used bootstrap methods to obtain 95% confidence intervals.
I had a look at the Wikipedia article for RR (http://en.wikipedia.org/wiki/Relative_risk) but its not the most helpful.