Patient Validation of Estimation of Health Utility Values in Alopecia Areata.

Abstract

Background: Current patient-reported burden measures, which guide decision-making, may not be sensitive to pertinent impacts of alopecia areata (AA). The UK public previously valued patient/caregiver vignettes using the time trade-off (TTO) method in interviews; however, the public may not fully understand the impact of AA. Therefore, this study aimed to evaluate the content validity of the vignettes using TTO interviews with patients with AA and to compare patient-derived utilities for each health state with the utilities derived from the UK public.

Methods: To understand their perspective surrounding trade-offs between quantity and quality of life, and to confirm the UK public's utility values, adult participants in the UK with AA currently experiencing scalp hair loss or with no scalp hair loss but experiencing hair loss in the last 12 months were recruited. In total, five AA vignettes that described health states by hair loss and its impacts and one caregiver vignette describing caring for an adolescent patient (aged 12-17 years) with AA were presented to participants in interviewer-guided sessions. Participants imagined themselves in the health state or as a caregiver, then valued each state using a visual analog scale (VAS) and traded time from 10 years in full health in 6-month increments to avoid living in each health state to evaluate the TTO utilities (0 [dead] to 1 [full health]).

Results: Among participants (N = 50), mean VAS scores (Severity of Alopecia Tool [SALT] 0-10: 74.3; SALT 11-20: 59.0; SALT 21-49: 39.4; SALT 50-100: 29.6; SALT 50-100 [no eyebrows/eyelashes]: 26.0; and caregiver [adolescent SALT 50-100]: 58.6) and TTO utility values (SALT 0-10: 0.93; SALT 11-20: 0.87; SALT 21-49: 0.67; SALT 50-100: 0.54; SALT 50-100 [no eyebrows/eyelashes]: 0.45; and caregiver [adolescent SALT 50-100]: 0.81) were lower for states with greater hair loss, similar to the mean UK public utility values. Over a 10-year time horizon, the average patient with AA was willing to trade approximately 5 years of life (mean TTO utility, 0.537 [standard deviation, 0.448]) to avoid impacts associated with 50-100% scalp hair loss.

Conclusions: This is the first known study to evaluate how patients with AA would make trade-offs between quantity of life and disease-specific quality of life. A high willingness to trade off duration of life was observed, consistent with the UK public study and supporting a high disease burden of AA.