topic Proc Logistic, set reference group without using formats? in Statistical Procedures

Proc Logistic, set reference group without using formats?

Tpham — Wed, 30 Oct 2013 23:07:01 GMT

I am running Proc Logistic. is there a way to run the class statement by putting the value instead of the format name? So in order to get my command to work I had to run the following:

proc logistic data = recode ;

class agegp (ref='2.age grp 45-65') sex (ref='1.Male') /param = ref;

model Y (event='1. <64') = agegp sex;

run;

So in this case, agegroup=2 and sex=1 are my reference groups (my format is value.category). I have tried doing the following:

proc logistic data = recode ;

class agegp (ref=2) sex (ref=1) /param = ref;

model Y (event=1) = agegp sex;

run;

The code above gives me a syntax error. I am hoping to avoid copying and pasting the format names. And hopefully make my code shorter.

Re: Proc Logistic, set reference group without using formats?

SteveDenham — Thu, 31 Oct 2013 12:48:30 GMT

If a format is assigned to the variable, the ref= syntax requires the use of the formatted value. See The Logistic Procedure>Syntax>CLASS Statement>REF= for the word on this.

Steve Denham

Re: Proc Logistic, set reference group without using formats?

Tom — Thu, 31 Oct 2013 14:17:13 GMT

Add a FORMAT statement to the PROC to clear the assigned formats from the variables.

proc logistic data = recode ;

format agegp sex ;

class agegp (ref=2) sex (ref=1) /param = ref;

model Y (event=1) = agegp sex;

run;

Re: Proc Logistic, set reference group without using formats?

SteveDenham — Thu, 31 Oct 2013 15:05:04 GMT

Sweet! I didn't know you could clear formats like that.

Steve Denham

Re: Proc Logistic, set reference group without using formats?

Tpham — Thu, 31 Oct 2013 15:30:07 GMT

Thanks! I this works... but is there a way to have the best of both worlds.. not having to type in the format in the class statement AND have it output with formats?

Re: Proc Logistic, set reference group without using formats?

Tom — Thu, 31 Oct 2013 15:39:12 GMT

Go to work for SAS and re-write PROC LOGISTIC?

The default reference is the largest value (unless you add the DESCENDING option).

So code your formats so that the reference value is the largest value.

Re: Proc Logistic, set reference group without using formats?

Reeza — Thu, 31 Oct 2013 16:08:57 GMT

Or smallest and use ref=first