Hello,
I am trying to account for time-at-risk ("risktime") as an offset variable in a logistic regression model. As far as I understand, it should not matter whether I use the option "exposure(risktime)" or "offset(lnrisktime)", where lnrisktime = ln(risktime), in the glm. However, I get two different results depending on how I specify the option. Is this a glitch that anyone else has come across? This is the basic format of the 2 codes:
glm y x1 x2 x3 , fam(binom) link(logit) offset(lnrisktime)
OR
glm y x1 x2 x3 , fam(binom) link(logit) exposure(risktime)
Thanks for your help,
-Kathryn
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