Run proc mixed with only specific parts of variable

[Angmar]

I'm trying to run proc mixed with a variable (drug) that has three components to it (drugs a, b, and c). How do I change the code to run proc mixed ONLY on drugs a and b?

PROC MIXED DATA=lec2.fevlong ORDER=DATA;
CLASS pid drug timehr;
MODEL y=drug timehr drug*timehr/S CHISQ;
REPEATED timehr /TYPE=UN SUBJECT=pid R RCORR;
RUN;

[ballardw · Accepted solution]

Without seeing actual values of the variable drug this is just a generic response:

Add a WHERE statement.

PROC MIXED DATA=lec2.fevlong ORDER=DATA;

WHERE data in ('drug a' 'drug b');
CLASS pid drug timehr;
MODEL y=drug timehr drug*timehr/S CHISQ;
REPEATED timehr /TYPE=UN SUBJECT=pid R RCORR;
RUN;