[R] Cox regression for prevalence estimates

[The Michaelson Institute]

Thnks to Prof. Frank E Harrell Jr , Prof. Bernardo Rangel Tura, and Prof. 
Thomas Lumley for their response.

Tomas Karpati (MD)
The Michaelson Institute for the prevention of Blindness
Hadassah Medical Org.
email: hadasa704 at 012.net.il
Phone: +972-2-6256458, fax: +972-2-6232895


On Tue, 07 Sep 2004 10:11:32 -0300, you wrote:
>At 09:27 07/09/2004, you wrote:
>
>>Bernardo Rangel Tura wrote:
>>>At , The Michaelson Institute wrote:
>>>
>>>>How can R be used to calculate the prevalence ratios using Cox regression +
>>>>robust variance estimates ?
>>>
>>>Well,
>>>In Design package have a command: cph
>>>This command have a option "robsut" with default=FALSE, but in help is write:
>>>" ... robust if TRUE a robust variance estimate is returned. ..."
>>>I think that is your response...
>>>
>>>bye
>>>Bernardo Rangel Tura, MD, MSc
>>>National Institute of Cardiology Laranjeiras
>>>Rio de Janeiro Brazil
>>
>>No, robust is an option to coxph, not cph.  cph uses 'after the fit' 
>>correction using the robcov or bootcov functions in Design.
>>
>>
>>--
>>Frank E Harrell Jr   Professor and Chair           School of Medicine
>>                      Department of Biostatistics   Vanderbilt University
>
>Sorry Frank!
>I made a digitation mistake, but I think yours package answers the Tomas 
>Karpati´s need.
>
>
>Thanks in advance
>
>Bernardo Rangel Tura, MD, MSc
>National Institute of Cardiology Laranjeiras
>Rio de Janeiro Brazil  
>