A mixed-methods study validated the Total Vitiligo Area Scoring Index and Facial Vitiligo Area Scoring Index as reliable measures for assessing vitiligo treatment efficacy, while establishing that meaningful clinical improvement can occur at lower thresholds than previously used.
In the study, published in JAMA Dermatology, investigators analyzed data from a phase II multicenter randomized clinical trial conducted across 35 sites internationally. The study included 164 participants (mean age = 46 years, 63% female) with nonsegmental vitiligo for psychometric analysis and 14 participants for qualitative assessment.
The trial protocol included a 35-day screening period, 24-week double-blind treatment phase, 28-week blinded extension, and 30-day follow-up. The participants received either upadacitinib (6, 11, or 22 mg/day) or placebo. Inclusion criteria required Total Vitiligo Area Scoring Index (T-VASI) ≥ 5 and Facial VASI (F-VASI)I ≥ 0.5 at baseline.
Statistical analysis demonstrated high test-retest reliability with intraclass correlation coefficients of 0.98 for T-VASI and 0.99 for F-VASI between baseline and week 4 in clinically stable patients. Calculations used absolute agreement 2-way mixed-effect models with time as a fixed event.
The T-VASI showed moderate correlations with Physician Global Vitiligo Assessment-Total (r = 0.63–0.65) and Patient Global Vitiligo Assessment-Total (r = 0.61 baseline, 0.53 week 24). F-VASI demonstrated moderate to strong correlations with Physician Global Vitiligo Assessment-Facial (r = 0.65–0.71).
Patient-reported impacts included sun sensitivity (n = 10), hair color loss (n = 8), and the need for skin covering (n = 10). The most commonly affected areas were face (n = 3), knees (n = 3), hands/fingers (n = 2), and arms (n = 2).
Analysis indicated that improvements of 30% in T-VASI and 50% in F-VASI reflected meaningful repigmentation between baseline and week 24. These thresholds were lower than the traditional T-VASI 50 and F-VASI 75 benchmarks used in clinical trials.
The study's statistical methodology included paired t-tests, Spearman correlations, and analysis of variance, with P < .05 considered significant. General linear models controlled for baseline score, age, sex, and Fitzpatrick skin tone.
Correlations between VASI measures and quality-of-life outcomes (VitiQoL, Dermatology Life Quality Index, Hospital Anxiety and Depression Scale) were nonsignificant (r ≤ 0.15).
The investigators noted limitations including a predominantly White, middle-aged, English-speaking study population and small qualitative sample size.
The study was funded by AbbVie and conducted in accordance with International Council for Harmonisation guidelines and the Declaration of Helsinki.
Conflict of interest disclosures can be found in the study.
