How to change the reference category in logistic regression analysis with Enterprise Guide?

[KekeK]

When running logistic regression with Enterprise Guide 5.1, how can I change the reference category within a parameter against which odds ratio estimates are presented? E.g. in below I would like to see how smoking occasionally (1) or daily (2) increases the odds of the health outcome as compared to smoking never (0) instead of comparisons 0 vs 2 and 1 vs 2. Odds Ratio Estimates Effect Point Estimate 95% Wald Confidence Limits Smoking 0 vs 2 0.878 0.189 4.075 Smoking 1 vs 2 0.291 0.040 2.123 Thanks!

[SteveDenham · Accepted solution]

When building your model, save your code.  In proc logistic, change (PARAM=EFFECT) to (PARAM=REF REF='0').  Then re-run with this change.  That should give you what you are looking for.

Steve Denham

[ChrisHemedinger]

You *might* be able to achieve it without hand-coding.  If your "dependent" var has 3 levels, then you can select "Ordered" or "Unordered" from the Model Response page, and then select the "Reference level" value.  I'm not sure if this gets you the content you're looking for, but maybe it will help.

Chris

[Reeza]

I think the OP is looking to change an independent variable not a dependent variable.

The model suggested would be a way of specifying a multinomial logistic regression instead of a logistic regression, from what I understand, though I'd have to check the code.

[KekeK]

Thanks, I did not know how to do this either so useful to know for the future but in here I wanted to change independent variable as pointed out by Reeza.

[KekeK]

Thank you! I was hoping this could be done without editing the codes, kind of odd that it cannot and hopefully something that will be fixed in future versions. A bit slower this way but otherwise works well.

[Reeza]

In general, if you're doing logistic or survival analysis, I found you very quickly need to step out of the EG GUI.