Hye, I am writing to request your help.
I am working on survival curve analysis with Cox model (cox.zph). After to test the proportionality condition for each covariant (independence to the time), the time effect is very significant and I must adapt my model, by the addition of a function dependent on the time for each time-dependent covoriant. My problem is I don’t know how determine this function. It seems there is a function “tt” in R which can help to find this function and integrate it in my Cox model. I am searching a good tutorial (or book reference) with example(s) to understand and apply the function “tt” in R; Thanks in advance Johann Delcourt ______________________________________________ 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.
