T-VASI and F-VASI Shown Reliable in Nonsegmental Vitiligo Assessment

Key Takeaways

• T-VASI and F-VASI showed high test-retest reliability.
• Meaningful improvement was defined as a 30% change in T-VASI and a 50% change in F-VASI scores over 24 weeks.
• This study shows significant clinical relevance at lower improvement percentages, suggesting historical thresholds may be conservative.

New research confirmed that the Total Vitiligo Area Scoring Index (T-VASI) and the Facial VASI (F-VASI) are reliable and valid tools for measuring meaningful improvement in patients with nonsegmental vitiligo. 

The study, published in JAMA Dermatology, included 164 adult participants enrolled in a phase 2, double-blind, randomized clinical trial conducted across 35 international sites. A total of 14 patients participated in qualitative interviews.

According to the psychometric analysis, there was 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 patients with stable vitiligo. There were also moderate-to-strong correlations between T-VASI and the Total-Physician Global Vitiligo Assessment (PhGVA-T), as well as between F-VASI and the Face-Physician Global Vitiligo Assessment (PhGVA-F), with r-values ranging from 0.63 to 0.71.

"This mixed-methods study found that the T-VASI and F-VASI are reliable, valid, able to differentiate between clinically distinct groups, and responsive in patients with nonsegmental vitiligo," the authors wrote. "The thresholds for meaningful change were lower than those historically used in clinical trials, suggesting that T-VASI 50 and F-VASI 75 are conservative estimates and reflect improvements that would be meaningful in patients with nonsegmental vitiligo."

Source: Ezzedine K, et al. JAMA Dermatology. 2024. Doi:10.1001/jamadermatol.2024.4534