The Cox Model

Survival Analysis in R

Heidi Seibold

Statistician at LMU Munich

Why use a Cox model?

$\rightarrow$ semiparametric model

$\rightarrow$ less strict distributional assumptions

Not possible:

Cox model:

cxmod <- coxph(Surv(time, cens) ~ horTh, 
               data = GBSG2)
coef(cxmod)

horThyes 
-0.3640099

Weibull model:

wbmod <- survreg(Surv(time, cens) ~ horTh, 
                 data = GBSG2)
coef(wbmod)

(Intercept)    horThyes 
  7.6084486   0.3059506

Survival Analysis in R