AIMS: Itch is a cardinal symptom of cutaneous lupus erythematosus (CLE) associated with reduced quality of life. Given the prominence of this symptom, a single patient-reported item assessing itch severity at its worst was evaluated with patients with CLE. The Worst Itch Numeric Rating Scale (NRS) is a potentially relevant patient-reported outcomes measure (PROM) assessing the severity of itch on a scale from 0 (no itch) to 10 (worst imaginable itch). Herein, we report the cognitive debriefing interviews (CDIs) conducted in patients with CLE to assess the relevance and comprehensibility of the Worst Itch NRS for this population.
METHODS: Individual interviews were conducted with 20 adults in the United States diagnosed with moderate or severe CLE (subacute and discoid subtypes). Participants reviewed the Worst Itch NRS in three rounds of interviews between February and June 2022. A semi-structured interview guide was developed to guide the interviews. Study participants were asked to ‘‘think aloud,’’ describing their thought processes as they read and responded to the item. Additionally, the instructions, item wording, 24-h and 7-day recall periods, and response options were debriefed for appropriateness and comprehensibility. Interviewers explored participants’ interpretations of item content and response options. The interview data were evaluated using thematic analysis.
RESULTS: The single item Worst Itch NRS was well understood and interpreted as intended by study participants. Participants reported that remembering experiences with their CLE-related worst itch over the past 7 days was not difficult. Item wording, instructions, and response options with anchors of 0 (no itch) and 10 (worst imaginable itch) and both the 24-h and 7-day recall periods were understood and interpreted as intended. No changes were made to the Worst Itch NRS item or instructions based on the feedback gathered in the CDIs.
CONCLUSION: This study provides evidence that itch is an important symptom in CLE and should be evaluated in the clinical trials of CLE treatment. Moreover, this study confirms the Worst Itch NRS with a 7-day recall to be a relevant and appropriate PROM for use in studies of CLE.
