Re: baseline survival in time-dependent model

[Terry Therneau <therneau@mayo.edu>]

 A Perperoglou asked:
 "after fitting a Cox time-dependent model I plot the survival function. I
know that S-plus estimates the Survival
at the mean value of the covariates, but what happens whith the time
dependent model?
What is the value of time that S-plus uses to estimate the survival
function?"

   The computation is easy, but there are several pitfalls with respect to
the interpretation or use of baseline survival curves after a Cox model
with time-dependent covariates.  See section 10.2.4 of the book by
Therneau and Grambsch for an extended discussion and examples.
        
                Terry Therneau