[R] PH Model assumption

[David Winsemius]

On Dec 10, 2009, at 12:11 PM, Ashta wrote:

> Hi all,
>
> I was trying to test the assumption of proportional hazards
> assumption, I used the cox.zph function
>
>> cox.zph(coxfit6)
>
> Results are:
>               rho        chisq        p
> x1          -0.0396    1.397   2.37e-01
> x2           0.1107    9.715   1.83e-03
> x3          -0.0885    7.743    5.39e-03
> x4           0.0366    1.092    2.96e-01
> x5           0.0242     0.455    5.00e-01
> GLOBAL     NA     30.952    9.57e-06
>
>
> Are all these covariates fulfilled the assumption of proportional  
> hazards?

Your two basic questions today suggest that you are either attempting  
to teach yourself survival analysis, or you are in a class with the  
same goal. You should consult your textbook, or if you don' t have a  
textbook, you should get one, or perhaps even a G-search with terms:

  proportionality "cox.zph".

-- 
David.

David Winsemius, MD
Heritage Laboratories
West Hartford, CT