Hello,

I want to check if the stroke location changed my outcome variable only for right vs left vs both hemispheres.

I want to have a regression analyze with the categorical predictor, which is the location, but I was thinking as I have more than three groups, and I want to check only right vs left vs both hemispheres

What should I do with the other groups? I meant how to treat with them.

I was thinking to put the other category under one category named others? this way I would have 4 categories, but only interpret the results for right vs left vs both and the reference group would be one of the right or left or both not the other group, am I right?

here is the categories:

right hemisphere

left hemisphere

both hemispheres

brainstem

cerebellum,

brainstem or cerebellum

both supra-infra-tentorial structures

or will be better thought?