43531 Validation of the Dermatology Life Quality Index (DLQI) in Prurigo Nodularis (PN) Based on Clinical Studies of Dupilumab in Adults with PN

Introduction: Prurigo nodularis (PN), a chronic inflammatory, itchy dermatosis, negatively impacts patients’ health related quality-of-life (HRQoL). The Dermatology Life Quality Index (DLQI) is the most frequently used patient-reported outcome measure of HRQoL in dermatology clinical trials, but it has not yet been validated in PN patients. This study validated the psychometric properties and estimated within-patient meaningful improvement threshold of DLQI in PN patients participating in two phase-3 dupilumab clinical trials. Materials and methods: Content validity was evaluated by conducting qualitative interviews (N=19). Psychometric and measurement properties of DLQI were assessed, using patient- and clinician-reported outcome data pooled from the two phase-3 trials (N=311; NCT04183335, NCT04202679) of dupilumab in adult PN patients uncontrolled on topical therapies.