categorical variables in proc logist

[lmyers2]

Hello,

I'm using SAS 9.4 full edition through a server. I will be running a logistic regression model with a very large data set (2700 observations in smaller group and 50000 observations in larger group). I have several categorical variables and am not sure how you program using the class statement and choosing the reference group for each, since I've only run a logistic regression model with 1 categorical variable. Can you help?

Thanks

Laura

[stat_sas]

Hi,

This can be extended for multiple categorical variables in class statement. Assuming var1 and var2 are two classification variables.

proc logistic data=have;

class var1 (param=ref ref='A') var2 (param=ref ref=first);

model dep_var (event='1')= var1 var2;

run;

[Reeza · Accepted solution]

Refer to the second example in the documentation which covers regression with categorical variables. 

Make sure to set the PARAM=REF on your model.