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Re: st: stcascoh.ado - CASE-cohort


From   Enzo Coviello <enzo.coviello@tin.it>
To   statalist@hsphsun2.harvard.edu
Subject   Re: st: stcascoh.ado - CASE-cohort
Date   Fri, 18 Apr 2003 13:00:47 +0200

At 15.35 17/04/2003 +0200, you wrote:
Hi,
I am using the stcascoh.ado to model a case-cohort dataset. To figure out how things work and if things go along properly, I tried to reproduce the example of BArlow (Barlow WE, Ichicawa L, Rosner D, and Izumi S: Analysis of Case-Cohort Designs; Journal Clinical Epidemiology 1999; 52: 1165-1172) from the Breslow and Day nickel dataset.
..... omissis

My problem is that I am not getting there and cannot reproduce the results (I tried it in SAS and it worked).
At examining the dataset after - stcascoh - I had the impression that weights were wrongly assigned in the programm in lines 179
and 184. But I am not very familar with the programming language.

stset age_stop,failure(icd==160) id(id) enter( age_strt) exit( age_stop) origin( age_emp)
In this statement you are using as time axis time since first employment.
Are you sure that in SAS codes time axis is the same?
If SAS' time axis is age you should omit "origin( age_emp)"


If this check confirms that Stata's results do not match SAS' results, please send me privately the output you obtained using SAS and I'll do some further inspection in stcascoh.ado.

Enzo


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