How do you adjust for significantly different baseline outcome measures in a longitudinal analysis?

1

Hello,

I need your expertise.

How do you adjust for significantly different baseline outcome measures in a longitudinal analysis? Is there a need to adjust for it? If so, is it appropriate to use the constrained longitudinal data analysis (cLDA)? cLDA is used where the main effect of Treatment is removed, i.e. treatment levels are constrained to have the same baseline mean of the response variable.

My formula in the mixed model: y ~ Time + Time*Treatment + (1|ID)

Appreciate your help. Thanks!

Regards,
Hanis

2

I just went to the trouble of responding to you at r - How to obtain contrasts for constrained longitudinal data analysis? - Cross Validated . Cross-posting is not very efficient. Please see my respond there. Briefly I think it is a mistake to treat baseline as an outcome.