What minimum baseline assessment do you consider necessary to make fatigue patient-reported outcomes interpretable in PBC studies, given confounding from depression, sleep disorders, thyroid disease, and autonomic dysfunction?

Interesting and challenging question. Normally, I would check TSH annually, do a sleep study, and then use my judgement to see if fatigue was related to PBC. I must admit I do not do the Fatigue Assessment Scale (FAS) test, which gives an assessment of the severity of fatigue but does not link to a ...