An Evaluation of Generic and Disease-Specific Patient-Reported Outcome Measures to Assess the Impact of Percentage of Scalp Hair Loss on Health-Related Quality of Life in a European Population

BackgroundHair loss due to alopecia areata (AA) can negatively impact patients' health-related quality of life (HRQoL). Patient-reported outcome measures (PROMs) like the EQ-5D-5L and the Alopecia Areata Patient Priority Outcomes (AAPPO) represent treatment outcomes and can guide decision-making. However, the EQ-5D-5L potentially underestimates AA-specific impacts, while the AAPPO may provide a more disease-specific assessment.ObjectivesThis study uses the EQ-5D-5L and the AAPPO emotional symptom (ES) and activity limitations (AL) subscales to characterise HRQoL among patients with AA.MethodsThis analysis uses secondary data from the Adelphi Alopecia Areata Disease Specific Programme (AA-DSP), a survey of dermatologists and patients with AA in five European countries. Included patients completed a survey containing the EQ-5D-5L and AAPPO. Descriptive summary statistics were reported for AAPPO ES/AL subscales and EQ-5D-5L scores, overall and stratified by physician-reported percentage of scalp hair loss (%SHL). Cramer's V effect sizes were calculated across each of the AAPPO ES/AL and EQ-5D anxiety/depression and usual activities items to examine the relationship between varying degrees of SHL and the PROMs.ResultsFour hundred thirty-five patients with AA completed the AAPPO and EQ-5D-5L. The mean (SD) overall EQ-5D-5L index and EQ-VAS score was 0.85 (0.15) and 74.07 (17.86), respectively. The mean (SD) overall AAPPO ES and AL subscale scores were 1.70 (1.03) and 0.88 (0.93), respectively. For the AAPPO ES and AL items, effect sizes were largest between the extreme values of SHL (0%-10% vs. 100%), while the effect sizes between intermediate SHL groups (e.g., 11%-20% and 21%-49%) tended to be smaller. The two EQ-5D-5L items demonstrated lower effect size values.ConclusionsOur findings suggest the AAPPO suitably discriminates between clinically relevant groups of patients with AA. The EQ-5D-5L was not as effective in measuring the specific psychological or social dimensions by SHL, potentially underestimating disease burden among patients with AA.