source("http://192.38.117.59/~linearpredictors/datafiles/readCsl.R")
library(survival)

## We would like the placebo group to be the reference group
csl$tment <- relevel(csl$tment, ref = "1")

model1 <- coxph(Surv(days, dc == 1) ~ asc + tment + asc:tment, data = csl)
summary(model1)