Hello,
I'm testing out some logistic regression models and I am comparing results across proc logistic, proc glimmix, and proc genmod. I wanted to first look at models without specifying any random effects. With these fixed effects models, I anticipate that the coefficient estimates would be the same across procedures; however proc logistic produces substantially different coefficient estimates for the fixed effects (proc glimmix and genmod produce the same coefficient estimates). Do you know what would be causing this? I've pasted example code below.
Addendum: I've noticed that the different parameter estimates are specifically for variables in the class statement (I am specifying the same reference category across models).
proc logistic data = dat desc;
class var1 (ref = "0");
model outcome = var1 var2 var3;
run;
proc glimmix data = dat;
class var1 (ref = "0");
model outcome = var1 var2 var3/solution dist=bin link=logit;
run;
proc genmod data = dat;
class var1 (ref = "0");
model outcome = var1 var2 var3/dist=bin link=logit;
run;
Parameter estimates output