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st: Poisson regression

From   [email protected]
To   [email protected]
Subject   st: Poisson regression
Date   Sun, 31 Jul 2005 20:49:53 +1000

Dear all
I am looking at the predictors of standardised mortality ratio (SMR) for my cohort. I have two datasets:
-the first one contains death; person-years of observation and different variable which i want to check as predictors of smr.
-the second dataset contains the rate of mortality (adjusted for sex and age) for the reference population.

After stset and stsplit in the first dataset, i merged it with the second one and calculated the expected number of death (e) for my cohort. In order to look at the predictors of smr i used the following syntax:

xi: poisson _d  i.psy  i.cob ......., exposure(e) irr. 

I wonder whether the selection of "e" as the exposure is correct when my dependent variable is smr?

When i fit different models, pseudo R^2 is very small (around 0.02) in all of them. This happens even when I include variables which influence smr. For all models use of poisgof gives a good results.
Thank you for your time
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