search for: survobject

...Surv(starttime, stoptime, event) ## Cox-regression coxph(survobj~group) # this works ## put Surv object in data.frame df.test <- data.frame(survobj=I(survobj), group) ## Cox-regression on data.frame coxph(survobj~group, data=df.test) # this does not work attr(df.test$survobj, 'class') # survobject has class "AsIs", "Surv" attr(df.test$survobj, 'class') <- c('Surv', 'AsIs') # put Surv first attr(df.test$survobj, 'class') # survobject has class "Surv", "AsIs" coxph(survobj~group, data=df.test) # now it works

Dear R-users, I computed a simple coxph model and plotted survival over time with associated confidence intervals for 2 covariate levels (males and females). M1 <- coxph(survobject~sex, data=surv) M1 survsex <- survfit(survobject~sex,data=surv) summary(survsex) plot(survsex, conf.int=T, col=c("black","red"), lty = c(1,2), lwd=c(1,2), xlab="Time", ylab="Survival probability") legend(10, 0.2, c("males","females"), c...