That sounds like a population inference rather than predicting at the individual level. If so, then the GEE model is probably what you want. But note that PROC GEE is the newer procedure for fitting this model and is recommended over GENMOD for that purpose. It uses essentially identical syntax. Also, it is not clear whether the response variable (Y in your initial post) is continuous or binary. If it is binary then you should specify the DIST=BIN in the MODEL statement. In any case, you should use the DIST= option to specify the appropriate distribution for your response variable.
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