First time posting a question, apologizes if I am not doing this correctly.

I have a placebo-controlled, 4-way crossover trial: (1) placebo, (2) drug A, (3) drug B, and (4) combo of drug A and B. Each patient has a baseline pain score (continuous, 0 to 10) and 4 separate "post-treatment" pain scores, one for each of the 4 drug regiments (placebo/drugA/drugB/combo)

I also have adverse effects reported for each of the drug regimens (eg. fatigue yes/no).

So, the primary outcome (pain) and secondary outcome (fatigue)

I would be interested to see if certain baseline characteristics (I can use them as continuous variables or turn them into categorical variables by binning) are associated with 1) pain response and 2) adverse events, but I am uncertain how to handle the cross-over nature of the data.

I would need, would appreciate any insights. (I am reading about the mixed effect model but I can't seem to understand how this would apply to my situation).


I have thought about doing

Model (reduction in pain drug A relative to placebo) ~ (baseline 1 + baseline 2 + baseline 3)
but it seems like I would have to repeat this 2 more times with (drug B relative to placebo) and (combo relative to placebo) and i'm not sure if that is correct.


Thanks,

Maggie