Date: Fri, 3 Nov 2006 11:06:24 -0500
Reply-To: Michael Ni <Michael.Ni@COGNIGENCORP.COM>
Sender: "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From: Michael Ni <Michael.Ni@COGNIGENCORP.COM>
Subject: Re: Proportional Hazard Model
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Thanks for your help! If there are 10 variables exist in the final
model, I need to check 10 interaction terms separately? In that case,
can I still check the assumption by using graphical techinuqe? If yes, how?
>Statistically, you use time-varying covariates that capture a
>systematic pattern of deviation for a constant HR. The simplest and
>most often use is a simple interaction between a categorical predictor
>and Time. A step above is an interaction with log of Time. From there
>sky is the limit if you have a non-monotonic departutre from
>proportional hazards. The key is to look at the change in hazard
>across time graphically!
>On Nov 3, 9:29 am, "Vadim Pliner" <Vadim.Pli...@VerizonWireless.com>
>>Michael Ni wrote:
>>>Could anyone tell me how to verify the assumption for proportional
>>>hazard model in SAS/PROC PHREG?
>>>Thanks a lot!
>>>MichaelThe SAS 9 documentation can tell you "how to verify the assumption for
>>hazard model in SAS/PROC PHREG": SAS/STAT -> PROC PHREG -> Assessment
>>of the Proportional Hazards Model - Experimental -> Checking the
>>Proportional Hazards Assumption. Or, you can read a section titled
>>"Checking the Proportional Hazards Assumption" in Alan Cantor's book
>>"Extending SAS Survival Analysis Techniques for Medical Research."