Relationship between Dermatology Life Quality Index Scores and EQ-5D-5L Utility Values in Adults with Atopic...

Atopic dermatitis (AD) is associated with impaired health-related quality of life (HRQoL), especially in moderate-to-severe disease. The Dermatology Life Quality Index (DLQI) is the most widely used dermatology-specific measure, whereas the EuroQol Five-Dimension, Five-Level questionnaire (EQ-5D-5L), a generic preference-based instrument, assesses health status across diseases. This study examined the relationship between DLQI and EQ-5D-5L in Swedish adults with ADatopic dermatitis and developed a mapping model to estimate EQ-5D-5L utilities from DLQI scores. In this cross-sectional study, 112 Swedish adults with self-reported physician-diagnosed ADatopic dermatitis, recruited through the Swedish Asthma and Allergy Patient Association, completed both questionnaires. DLQI scores correlated strongly and negatively with EQ-5D-5L index values (r=--0.64, p<0.001). Each 5-point increase in DLQI corresponded on average to a 0.07 decrease in EQ-5D-5L utility. A fractional logit regression model including covariates age, sex, and disease severity, showed good calibration and explained 27 % of the variance in EQ-5D-5L values. These findings demonstrate that DLQI scores meaningfully reflect generic HRQoL among adults with ADatopic dermatitis and can be used to estimate EQ-5D-5L utilities when preference-based data are unavailable. The results enhance understanding of how DLQI relaterelates to overall health status and support the application of DLQI-derived utilities in cost-effectiveness analyses and health technology assessments.