Which outcomes should we measure in vitiligo? Results of a systematic review and a survey among patients and clinicians on outcomes in vitiligo trials

Background Relevant and reliable outcomes play a crucial role in the correct interpretation and comparison of the results of clinical trials. There is a lack of consensus around methods of assessment and outcome measures for vitiligo, which makes it difficult to compare results of randomized controlled trials (RCTs) and perform meta-analysis. Objectives To describe the heterogeneity in outcome measures used in published RCTs of vitiligo treatments, and to report the most desirable outcomes from patients' and clinicians' perspectives. Methods We conducted a systematic review of outcome measures used in RCTs as well as a survey of the most desirable outcomes identified by patients and clinicians as part of a Vitiligo Priority Setting Partnership. Results Outcomes from 54 eligible trials were analysed and compared with outcomes suggested by patients and clinicians. In the systematic review, 25 different outcomes were reported. Only 22% of trials had clearly stated primary outcome measures. Repigmentation was the most frequently reported outcome in 96% of trials and was measured using 48 different scales. Only 9% of trials assessed quality of life. Thirteen per cent measured cessation of spreading of the disease and 17% of studies reported patients' opinions and satisfaction with the treatment. In contrast, out of 438 suggestions made by patients and clinicians, cosmetically acceptable repigmentation (rather than percentage of repigmentation) was the most desirable outcome (68%), followed by cessation of spread of vitiligo (15%), quality of life (8%) and maintenance of repigmentation (4%). Conclusions We propose that future vitiligo trials should include repigmentation, cosmetic acceptability of results, global assessment of the disease, quality of life, maintenance of repigmentation, stabilization of vitiligo and side-effects. International consensus among clinicians, researchers and patients is needed to establish an agreed core outcome set for future vitiligo trials.