Using qualitative methods to establish the clinically meaningful threshold for treatment success in alopecia areata.

This qualitative investigation of expert clinicians-then-patients with AA confirmed that achieving an amount of 80% or more scalp hair (SALT score ≤ 20) was an appropriate individual treatment success threshold indicating clinically meaningful improvement for patients with ≥ 50% scalp hair loss. A qualitative investigation of a quantifiable treatment success threshold is possible through a well-designed interview process with expert clinicians and the appropriate patient population.