P066 Core outcome set implementation in vitiligo clinical trials: barriers and facilitators from a survey of lead researchers

Abstract Core outcome sets (COSs) standardize outcome measures across clinical trials, ensuring consistency and comparability of results. In 2015, an internationally agreed COS for vitiligo randomized clinical trials (RCTs) identified three essential outcomes: repigmentation, side-effects/harms, and maintenance of gained repigmentation. Despite its significance, adoption of the COS across vitiligo trials has been inconsistent. This study evaluated COS uptake, barriers to implementation, and facilitators. Eighty-five authors of vitiligo RCTs between 2016 and 2021 were identified through a systematic review evaluating COS uptake, and were contacted via email. Recruitment occurred between July and November 2024, and 36 authors completed the Google Forms survey (response rate 42%). Respondents, predominantly dermatologists worldwide, described awareness and integration of COS domains within their trials. Quantitative results revealed that all respondents incorporated repigmentation as an outcome, and 97% assessed side-effects/harms. However, maintenance of gained repigmentation was measured by only 64% of respondents. Among the four recommended outcomes, 67% of respondents evaluated cosmetic acceptability and quality of life, while tolerability/burden of treatment and cessation of spreading were assessed less frequently (50% and 47%, respectively). Thematic analysis identified barriers to COS implementation. The most cited challenge (44%) concerned long-term follow-up to assess maintenance of gained repigmentation, with many noting cost and resource constraints. Additionally, 28% highlighted the impracticality of assessing maintenance in early-phase trials, where efficacy was the primary focus – despite only late-phase trials being surveyed. Ambiguity in defining certain domains, such as cessation of spreading, was reported by 19%, particularly in trials of stable vitiligo. Some respondents (8%) noted that repetitive data collection burdened patients and trial staff, contributing to incomplete datasets. To enhance uptake, respondents recommended increasing awareness of COS outcomes through public campaigns and academic presentations (53%). Simplifying and validating measurement tools for COS outcomes was suggested by 36%, alongside calls for journal reviewers to require COS adherence during manuscript submission (32%). A tiered outcome collection approach was also proposed, prioritizing repigmentation and side-effects in initial trials, with maintenance in long-term follow-ups. This evaluation underscores the need for flexible COS implementation reflecting practical challenges of vitiligo RCTs. While adoption of repigmentation and side-effects measures reflects COS awareness, gaps in assessing maintenance of repigmentation highlight persistent barriers. Given that most vitiligo RCTs span 52–54 weeks, yet 40% of patients relapse within 3–4 months post-treatment, tracking long-term maintenance is vital. Addressing logistical and definitional challenges, refining outcome frameworks, and fostering collaboration between researchers, industry and journal reviewers will be essential to facilitate COS adherence. These findings will inform ongoing COS refinement and support a planned complementary survey of dermatology journal editors to evaluate COS uptake at the publication level.