Message-ID: <200902261428.n1QESjg27531@hsrnfs-101.mayo.edu>
Date: 2009-02-26T14:28:45Z
From: Terry Therneau
Subject: survival::survfit,plot.survfit
> plot(survfit(fit)) should plot the survival-function for x=0 or
> equivalently beta'=0. This curve is independent of any covariates.
This is not correct. It plots the curve for a hypothetical subject with x=
mean of each covariate.
This is NOT the "average survival" of the data set. Imagine a cohort made up
of 60 year old men and their 10 year old grandsons: the expected survival of
this cohort does not look that for a 35 year old male.
Terry T