Hi there, I need some help to figure out what is the proper model in survival analysis for my data. Subjects were randomized to 3 treatments in trial 1, some of them experience the event during the trial; After period of time those subjects were randomized to 3 treatments again in trial 2, but different from what they got in 1st trial, some of them experience the event during the 2nd trial (I think the carryover effect can be ignored since the time between two trials is long enough.)
What I am interested is whether the survival functions differ among treatments. How should I deal with the correlation between the observation since the same subject was treated with two different drugs in two trials? Should I add "TRIAL" , "whether the event happened before", or "number of times the event happened before" as covariate(s)? Any input will be appreciated. Thank you. Qian [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.