Dear SAS community, I'am measuring Prevalence Ratio with modified poisson regression (because the outcome prevalence is high and binomial regression did not converge). I would like to introduce an interaction term into the model but it does not run and I have no error message. I only have binary variables. Here is the code that i have executed: proc genmod data=mydata; class exposure(ref="0") sex (ref="0") age(ref="0") id //param=ref; model outcome=exposure sex exposure*sex age_2class /dist=poisson link=log; repeated subject=id/type=unstr; estimate "exposure" exposure 1 0/exp; estimate "sex" sex 1 0/exp; estimate "age" age 1 0/exp; run; The number of subjects is very high (in million), and i have a total of 15 confounding variables. Without the interaction term the model is running, What is my mistake ? Also, do you know how to write the estimate statement for the interaction term ? Thanks for your help !
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