Hi,
I'm running a cox model regression with a covariate that has three categories (3 time periods: 0,1 or 2). I'm running it in a univariate model first like this:
model <- coxph(Surv(time1, time2, treatment) ~ period, data = two, ties="efron")
The results I get (see below) do not seem to take into account that there are 3 categories? Is there a way I can specify this?
coef exp(coef) se(coef) z Pr(>|z|)
period 0.2225 1.2491 0.1764 1.261 0.207
exp(coef) exp(-coef) lower .95 upper .95
period 1.249 0.8005 0.884 1.765
Thank you!