Proc GENMOD Class question

fayez61 — Fri, 28 Oct 2016 14:42:27 GMT

Hello,

I want to know if there is a way that I can elimnate refrence option in class statement using genmod procedure?

Because when I run my model, it gives me the last category of each variable in the class as a reference to that variable.

Re: Proc GENMOD Class question

RyanSimmons — Wed, 02 Nov 2016 15:53:13 GMT

There are multiple ways to paramaterize class variables. You can change the paramaterization in the CLASS statement with the PARAM option.

e.g.:

PROC GENMOD data=data;
     class treatment / param=X;
     model outcome = treatment;
run;

where X is any of the options detailed here (e.g. ref, effect, glm, etc.). The default is the glm parameterization:

You can also use the REF option to specify the reference level.

e.g.:

PROC GENMOD data=data;
     class treatment(ref='Control');
     model outcome = treatment;
run;