I am confused when trying the function survfit. my question is: what does the survival curve given by plot.survfit mean? is it the survival curve with different covariates at different points? or just the baseline survival curve?
for example, I run the following code and get the survival curve #### library(survival) fit<-coxph(Surv(futime,fustat)~resid.ds+rx+ecog.ps,data=ovarian) plot(survfit(fit,type="breslow")) summary(survfit(fit,type="breslow")) #### for the first two failure points, we have s(59|x1)=0.971, s(115|x2)=0.942 how can we guarantee that s(59|x1) is always greater than s(115|x2)? since s(59|x1)=s_0(59)^exp(\beta'x1) and s(115|x2)=s_0(115)^exp(\beta'x2), we can manipulate covariates to make s(59|x1) < s(115|x2), right? do I miss anything? thanks in advance Jeff -- View this message in context: http://www.nabble.com/survival%3A%3Asurvfit%2Cplot.survfit-tp22206954p22206954.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ 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.
