Dear All, I have a question regarding the output of survfit() when I supply a Cox model. Lets say for example:
library(survival) fit <- coxph(Surv(time, status == 2) ~ factor(spiders), data = pbc) fit # HR for spiders is significant newdata <- data.frame(spiders = factor(0:1)) sf <- survfit(fit, newdata = newdata) sum.sf <- summary(sfit, times = c(2000, 2500, 3000)) # survival estimates for the yes/no spiders # and the 3 follow up times sum.sf$surv # corresponding lower limits of the # 95% CI sum.sf$low # corresponding upper limits of the # 95% CI sum.sf$up we observe that the 95% CIs overlap!! How is this possible since the HR for spiders is significant. Regards, Mura ______________________________________________ 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.