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) ~ tment, data = csl) summary(model1) model2 <- coxph(Surv(days, dc == 1) ~ asc, data = csl) summary(model2) model3 <- coxph(Surv(days, dc == 1) ~ tment + asc, data = csl) summary(model3)