A method for assessing rater reliability in applying the Vitiligo Area Scoring Index (VASI).

The Vitiligo Area Scoring Index (VASI) is a tool for measuring repigmentation after patients undergo vitiligo treatment, offering a standardized, quantitative scale without the need for specialized equipment. For large multicentre trials that require multiple raters, VASI must be consistently applied to generate interpretable data; therefore, a method for assessing rater reliability would improve data integrity for large clinical studies of vitiligo. This study aimed to assess a method for determining the reliability of VASI raters by evaluating raters of different levels of experience relative to a gold standard.