Stata The Stata listserver
[Date Prev][Date Next][Thread Prev][Thread Next][Date index][Thread index]

st: poisson regression with lexis expansion and poisgof command


From   mark tracy <mark.tracy@ozemail.com.au>
To   statalist@hsphsun2.harvard.edu
Subject   st: poisson regression with lexis expansion and poisgof command
Date   Sat, 26 Mar 2005 17:38:16 +1100

Dear All,

I am a novice learing stata......this is probably very basic but Im struggling a bit.
I have a cohort study of miners developing TB who are HIV +ve or -ve over a 8 year study period.. I have found the best poisson regression model testing with LRTs I have included a lexis expansion for age of subject effects. The Stat manual on poisgof makes no mention of compressing the data. I have read that ungrouped data is not correct for this command.

my final model looks like this xi:poisson _d i.hiv ageband2 i.prevtb i.sil if sil~=.,e(y) irr

I have used the following commands to compress the data before doing the poisgof

preserve

. collapse (sum) _d y,by(hiv ageband2 job1 prevtb sil)

. xi:poisson _d i.hiv ageband2 i.job1 i.prevtb i.sil if sil~=.,e(y) irr
(output ommitted)

then poisgof

I am sorry if there is insufficient information I am not sure how much to include.

Many thanks for help in this matter.

sincerely



Mark Tracy
Director and Neonatologist
Nepean Newborn Intensive Care Unit
SWAHS
Lecturer Department of Paediatrics and Childhealth
Sydney University

*
* For searches and help try:
* http://www.stata.com/support/faqs/res/findit.html
* http://www.stata.com/support/statalist/faq
* http://www.ats.ucla.edu/stat/stata/




© Copyright 1996–2014 StataCorp LP   |   Terms of use   |   Privacy   |   Contact us   |   What's new   |   Site index