Development and validation of a patient-reported outcome measure for hair loss treatment: The HAIR-Q

Background: Patient-reported outcome measures (PROMs) for hair loss focus mainly on Alopecia Areata. We created a PROM (i.e., HAIR-Q) that is applicable to any hair loss condition. The HAIR-Q measures satisfaction with hair. Patients/Methods: Concept elicitation interviews were conducted and analyzed to develop a draft scale. Content validity was established through multiple rounds of patient and expert input. Psychometric properties of the scale were examined in an online sample (i.e., Prolific) using Rasch measurement theory (RMT) analysis. Test–retest reliability and tests of construct validation were examined. Results: Content validity of a 22-item draft scale was established with input from 11 patients, 12 experts and an online Prolific sample of 59 people who had a variety of hair loss treatments. In the RMT analysis (n = 390), 8 items were dropped. Data for the 14-item scale fit the Rasch model (χ² = 89.85, df = 70, p = 0.06). All 14 items had ordered thresholds and good item fit. Reliability was high with person separation index and Cronbach alpha values ≥0.91, and intraclass correlation coefficient of 0.94 based on a sample of 97 participants. Higher (better) scores on the scale were associated with having more hair, looking younger than ones' age, satisfaction with hair overall, being less bothered by hair loss, and for those who had a hair loss treatment in the past year, being more satisfied with their hair now than before treatment (p < 0.001). Conclusion: The HAIR-Q evidenced reliability and validity and can be used in research and to inform clinical care to measure satisfaction with hair from the patient perspective.