Hi,   I encountered a trouble when I wanted to use PROC MIANALYZE with poisson regression with robust error variance, which was performed by PROC GENMOD + repeated statement (see link ESTIMATE RELATIVE RISK IN SAS USING PROC GENMOD)   According to the example on SAS website (Reading Generalized Linear Model Results), I need three dataset to make MIANALYZE work. They are datasets for parameter estimates, parameter information and covariance matrix. Because my procedure is for poisson regression with repeated statement, I output three tables "GEEEmpPEst", "ParmInfo" and "CovB" for the three datasets needed.   The issue is, the approach works when I have only one predictor but does not work if I had multiple predictors. The error info says "CovB" was not created, which basically means it does not generate the CovB dataset. I tried to get table "GEERCov" and "GEENCov" and none of them exist.   My question is, how can I get a covariance matrix from a model with more than one predictor using poisson regression with robust error variance, to apply to the MIANALYZE procedure?   Thank you! ... View more