Re: st: RE: Comparison in survival analysis

["Frederick J. Boehmke" <frederick-boehmke@uiowa.edu>]

Have you looked into the -streg- option -ancillary()- ? This will allow 
you to specify covariates explaining the shape parameter in the Weibull.

On Sun, 26 Aug 2007, Aysegul Aydin wrote:


> Date: Sun, 26 Aug 2007 10:58:42 -0600
> From: Aysegul Aydin <Aysegul.Aydin@Colorado.EDU>
> Reply-To: statalist@hsphsun2.harvard.edu
> To: statalist@hsphsun2.harvard.edu
> Subject: st: RE: Comparison in survival analysis
>
> Ali,
>
> I was asking POLMETH a few weeks ago about a user-written or canned Stata
> method to estimate generalized weibull though without much luck. Christopher
> Zorn also adopted the same method in his 2000 Political Analysis article
> "Modeling Duration Dependence". This is a method I believe that allows the
> user to model the shape parameter with covariates. However, Zorn was using
> LIMDEP, so I am not sure whether this is doable in Stata. But if any of our
> colleagues have an idea about how to do this, I will also greatly appreciate
> their feedback.
>
> My best wishes,
>
> Aysegul
>
> -----Original Message-----
> From: owner-statalist@hsphsun2.harvard.edu
> [mailto:owner-statalist@hsphsun2.harvard.edu] On Behalf Of khan ali
> Sent: Sunday, August 26, 2007 6:24 AM
> To: statalist@hsphsun2.harvard.edu
> Subject: st: Comparison in survival analysis
>
> Dear members,
> For the same data set,the estimated parameters(two
> parametrs,alpha and beta(slope)) by weibull and
> loglogistic models narrate a different story(having
> different signs).How do the parameters of two
> distribiutions can be compared?
>
> The generalized weibull of Mudholkar,et al.(1996)
> provides much greater flexibilty at the expense of an
> additional shape parameter(having two shape parameters
> and in total three parameters).How do we can estimate
> this three parameter weibull distribution.
>
> Thanks for comments and suggestions.
> KHAN,ALI
>
>
>
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                                                         - Fred

Note updated contact info (effective August 01, 2007):

 < ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 >  Frederick J. Boehmke
 <  Associate Professor of Political Science
 >  University of Iowa
 <  341 Schaeffer Hall
 >  Iowa City, IA 52242
 <
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 <
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