Re: [R] Age as time-scale in a cox model

You asked about survival curves with age scale versus follow-up scale. > fit1 <- coxph(Surv(time/365.25, status) ~ t5 + id + age, data=stanford2) > surv1<- survfit(fit1) > surv1 n events median 0.95LCL 0.95UCL 157.000 102.000 1.999 0.898 3.608 > summary(surv1, times=3) time n.ri

[R] Age as time-scale in a cox model-How to calculate x-time risk?

Dear R users, My question is more methodology related rather than specific to R usage. Using time on study as time in a cox model, eg: library(Design) stanf.cph1=cph(Surv(time, status) ~ t5+id+age, data=stanford2, surv=T) #In this case the 1000-day survival probability would be: stanf.surv1=su