Dear all, I was wondering if anyone can help? I am an R user but recently I have resorted to SAS to calculate the probability of the event (and the associated confidence interval) for the Cox model with combinations of risk factors. For example, suppose I have a Cox model with two binary variables, one for gender and one for treatment, I wish to calculate the probability of survival for the combinations of 1s and 0s for both variables. In SAS the following code would be used.
I have used the code below to obtain the survival estimates (at 1 year) and confidence intervals for combinations of risk factors for my outcome. /* Combinations of Risk Factors */ data test2; input sex treat; DATALINES; 0 0 1 0 0 1 1 1 ; run; /* Survival estimates for the above combinations */ proc phreg data = pudat2; model withtime*wcens(0) = sex treat /ties = efron; baseline out = surv2 survival = survival lower = slower upper = supper covariates = test2 /method = ch nomean cltype=loglog; run; /* Survival estimates at 1 year */ proc print data = surv2 noobs; where withtime = 364; run; I now would like to do the same thing but in a competing risks setting (cumulative incidence rather than Cox model version (crr from cmprsk in R) however there is no pre-set routine for this in SAS. I am therefore keen to use R to obtain the survival estimates for both the overall outcome and the competing risks outcomes. Can anyone help me to translate the SAS code above into R code so that I can check I am doing things correctly? I am using R version 2.9.2 on Windows XP Professional. I think it would begin as follows: library(cmprsk) fit1 <- coxph(Surv(withtime,wcens)~ sex+treat,data=pudat2) my.fit <- survift(fit1) summary(my.fit) Unfortunately, the estimates shown do not match those of SAS. Additionally, can you use survfit with crr? If not, any suggestions as to how I may obtain the necessary estimates in a competing risks setting? Thank you for any help you can give. Laura [[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.