I have an intervention that is intended to reduce sedentary behaviour. I'm testing the experimental and control groups at four times (baseline, post-intervention 9 months later, 6 month follow-up and 12 month follow up).
Some examples that I have seen of similar analyses regress the intercept and slope values on group. But I can't see why you would regress the intercept when it's a baseline value. As far as I can see, group membership should only affect the slope value.
iSED sSED | sed1@0 firstname.lastname@example.org email@example.com firstname.lastname@example.org sSED ON IntGrp
My model is a bit more complex but this is roughly what I mean.