OBJECTIVES: A phase 3 trial (NCT04681729) of dupilumab among chronic inducible cold urticaria (ColdU) patients evaluated its efficacy and safety versus placebo was conducted. Patients reported outcome measures (PROMs) were used to inform efficacy endpoints, including Cold Urticaria Activity Score (ColdUAS), Urticaria Control Test (UCT), Dermatology Life Quality Index (DLQI) and Children DLQI (CDLQI) and Infant’s Dermatitis Quality of Life (IDQOL). In this qualitative study, we determined the relevance, comprehensiveness, and comprehensibility of those PROMs through cognitive debriefing (CD) interviews.

METHODS: One-to-one CD interviews were conducted by telephone with adult, adolescent, and children (dyad/caregiver only) with ColdU, using a structured interview guide.

RESULTS: Eight adults, five adolescents, six children with their caregivers and one caregiver of a 2-year-old child were interviewed. The seven adults and adolescents who debriefed ColdUAS found the instrument relevant to their experience; some had difficulties in understanding the wording (e.g., the term ‘wheals’ (n=3/7)). The six patients who debriefed UCT found it relevant (n=6/6) and items were well understood (n=5/6). According to six caregivers, most CDLQI items were found relevant to their ColdU children’s experience and demonstrated good content validity. However, a few children requested their caregiver's help to understand some items (e.g., the item related to holiday time (n=1/6)). The unique caregiver who was interviewed on IDQOL (initially designed for eczema) has misunderstood the instructions and stated that the items were irrelevant to their child’s experience.

CONCLUSIONS: Content validity of ColdUAS, UCT, and DLQI/CDLQI was demonstrated, indicating that they could effectively inform key ColdU symptoms, disease activity and impact-related efficacy endpoints in clinical trials, except IDQOL which needs further investigation to assess its content validity.