SAS Defaults for Proc Freq in CMH DIF analysis

Jaime2 — Tue, 22 Oct 2019 20:49:33 GMT

Hi All,

This seems like a silly question but I cannot figure out what default scheme is used to assign the "reference" and "focal group" in a typical differential item functioning analysis using PROC FREQ.

My code is :

proc freq data=mydata;
tables stratum*gender*item&i./CMH noprint;
output out=item&i. MHCHI COMOR CMH ; run;

My gender variable is not dummy coded and has values = Male , Female.

Would SAS use Females as the reference group since F comes before M, alphabetically? There has to be a rule documented someplace but I cannot find it. Of course my results are meaningless without knowing this.

Thanks for any tips or links.

Re: SAS Defaults for Proc Freq in CMH DIF analysis

Watts — Tue, 22 Oct 2019 21:38:43 GMT

The ORDER= option in the PROC FREQ statement specifies the order of the variable levels.

The default is ORDER=INTERNAL, which orders the levels by unformatted values ('Female' before 'Male').

topic SAS Defaults for Proc Freq in CMH DIF analysis in SAS Procedures

SAS Defaults for Proc Freq in CMH DIF analysis

Re: SAS Defaults for Proc Freq in CMH DIF analysis