Good morning, Sorry to trouble the list.
I have a problem I hope to seek your advice on. Essentially, I am trying to 'validate' a multivariate Cox proportional hazards model built in a training set, by testing it on an external test set. I have performed a survfit using the Cox model to predict survival for the test set, and obtained individual predictions for survival time, with standard error for each test sample. Each of these cases has an actual survival time, some censored. How can we decide whether the Cox model has been validated or not? I was suggested survdiff in the survival package, but survdiff works between curves; am not sure how I could use it (I have a predicted curve for each curve, but no 'observed curve' - the only observation is death or censoring at time x) Thank you all so much! Min-Han Tan Van Andel Institute ______________________________________________ [EMAIL PROTECTED] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
