Interaction test between SEX and QUARTILES with a BINARY OUTCOME

[natasha_nf]

Hello,

I want to check if there is an interaction between sex and quartiles of soda consumption in the case of a binary outcome.

How should I proceed?

exposure: quartiles of soda consumption

outcome: presence or absence of depression

covariate sexe: female, male

Thank you in advance!

[StatDave]

Fit a logistic regression model including the interaction. These statements will include a test for the interaction (sex*consumption). It assumes that your response variable is a character variable ("present" or "absent"), that the event of interest is presence of depression, and that you want to treat consumption as a continuous effect in the model. 

proc logistic;
class sex / param=glm;
model outcome(event="present") = sex consumption sex*consumption;
run;

[natasha_nf]

Thank you very much!

In the case of a multinomial outcome, i.e.: different mental disorders, would the procedure be the same?

[Ksharp]

Logistic Regression ?

proc logistic data=have;

class sex;

model outcome=SEX QUARTILES SEX*QUARTILES;

run;

[natasha_nf]

Thank you very much!

In the case of a multinomial outcome i.e.: different mental disorders, would the procedure be the same?

[StatDave]

Yes, but if the response is nominal (unordered), you need to add the LINK=GLOGIT option in the MODEL statement. If it is ordinal (ordered), no change is needed.