Proc genmod: Exponentiated with 95% confidence interval

[Liamb]

Hello,

I used the following code to estimate the difference between the case and the control in matched data, but I would like to have the exponential of the difference and its 95% confidence interval? Is there an option in genmod or gee that would allow me to do this?
Then I also need to estimate the exponential of the difference and its confidence interval adjusted for other variables.

proc genmod data=tab;
class paired group;
model cci=group/ dist=negbin link=log type3 cl ;
repeated subject=paired/ type=ind;
lsmeans group/ diff exp;
run;

Thanks

[StatDave · Accepted solution]

I assume that what you mean is that you want the difference in the group means which is not what the DIFF option in the LSMEANS statement gives you. If you add the ILINK and CL options in the LSMEANS statement, Mean and confidence limits  columns will be added in the LS-means table showing the individual group means and confidence intervals on the response. But the estimates in the LS-means differences table are differences of log means (or log ratios of means) and the values in the Exponentiated columns are ratios of means. To get estimated differences of means and confidence limits on the differences, use the NLMeans macro. See Example 1 in the Results tab of the macro documentation.