Dear all, I struggled to figure out how to derive SD and confidence interval for difference between groups in percentage change from baseline, analyzed in log-transformation.    In proc mixed, I have [log(Post) - log(BL)] as response. and treatment as indepent variables, visit, and treatment by visit interaction. So I know, the coefficient beta1 for treatment (and beta0 as intercept), I can transform back to get the percentage change (exp(beta0+beta1) - 1)*100%.    However what I am interested in is the difference between the group.  [exp(beta0+beta1)-1] - [exp(beta0)-1] = exp(beta0)*(exp(beta1) - 1)   How can I derive the SD and CI of the above with the LSmeans output?  Any reference I can go to?    Many thanks! Carrie      ... View more