Development of the Scalp Hair Assessment PRO™ measure for alopecia areata

Background Valid patient-reported outcome (PRO) measures are required to evaluate alopecia areata (AA) treatments. Objectives To develop a content-valid and clinically meaningful PRO measure to assess AA scalp hair loss with scores comparable with the five-response-level Alopecia Areata Investigator Global Assessment (AA-IGA (TM)). Methods A draft PRO measure was developed based on input from 10 clinical experts in AA. The PRO measure was cognitively debriefed, modified and finalized through two rounds of qualitative semistructured interviews with patients with AA who had experienced >= 50% scalp hair loss. Data were thematically analysed. Results Adults (round 1: n = 25; round 2: n = 15) and adolescents aged 15-17 years (round 1: n = 5) in North America participated. All patients named scalp hair loss as a key AA sign or symptom. Patients demonstrated the ability to self-report their current amount of scalp hair using percentages. In round 1 not all patients interpreted the measurement concept consistently; therefore, the PRO was modified to clarify the measurement concept to improve usability. Following modifications, patients in round 2 responded without difficulty to the PRO measure. Patients confirmed that they could use the five-level response scale to rate their scalp hair loss: no missing hair, 0%; limited, 1-20%; moderate, 21-49%; large, 50-94%; nearly all or all, 95-100%. Almost all patients deemed hair regrowth resulting in <= 20% scalp hair loss a treatment success. Conclusions The Scalp Hair Assessment PRO (TM) is a content-valid, clinically meaningful assessment of distinct gradations of scalp hair loss for evaluating AA treatment for patients with >= 50% hair loss at baseline.