Validation of the Vitiligo Noticeability Scale: a patient-reported outcome measure of Vitiligo treatment success

Batchelor, J.M.; Tan, Wei; Tour, S.; Yong, A.; Montgomery, Alan A.; Thomas, K.S.

Abstract

Background:
Patient-reported outcome measures are rarely used in vitiligo trials. The Vitiligo Noticeability Scale (VNS) is a new patient-reported outcome measure assessing how ‘noticeable’ the vitiligo patches are after treatment. The noticeability of vitiligo after treatment is an important indicator of treatment success from the patient’s perspective.

Objectives:
This study aimed to evaluate the construct validity, acceptability and interpretability of the VNS. Our main hypothesis was that the VNS would be a better and more consistent indicator of treatment success than percentage repigmentation.

Methods:
Clinicians (n=33) and patients with vitiligo (n=101) examined 39 image pairs, each depicting a vitiligo lesion pre- and post-treatment. Using an online questionnaire, respondents gave a global assessment of treatment success and a VNS score for treatment response. Clinicians also estimated percentage repigmentation of lesions (<25; 25-50; 51-75; >75). Treatment success was defined as ‘Yes’ on global assessment, a VNS score of 4 or 5, and more than 75% repigmentation. Agreement between respondents and the different scales was assessed using kappa statistics.

Results:
VNS scores were associated with both patient- and clinician-reported global treatment success (κ = 0.54 and κ = 0.47, respectively). Percentage repigmentation showed a weaker association with patient- and clinician-reported global treatment success (κ = 0.39 and κ = 0.29, respectively). VNS scores of 4 or 5 can be interpreted as representing treatment success. Images depicting post-treatment hyperpigmentation were less likely to be rated as successful.

Conclusions:
The VNS is a valid patient-reported measure of vitiligo treatment success. Further validation of the VNS is required, using larger sets of clinical pre- and post-treatment images, affecting a wider range of anatomical sites.

Citation

Batchelor, J., Tan, W., Tour, S., Yong, A., Montgomery, A. A., & Thomas, K. (2016). Validation of the Vitiligo Noticeability Scale: a patient-reported outcome measure of Vitiligo treatment success. British Journal of Dermatology, 174(2), https://doi.org/10.1111/bjd.14208

• Journal Article Type: Article
• Acceptance Date: Sep 23, 2015
• Online Publication Date: Dec 14, 2016
• Publication Date: Feb 12, 2016
• Deposit Date: Sep 19, 2017
• Publicly Available Date: Sep 19, 2017
• Journal: British Journal of Dermatology
• Print ISSN: 0007-0963
• Electronic ISSN: 1365-2133
• Publisher: Oxford University Press (OUP)
• Peer Reviewed: Peer Reviewed
• Volume: 174
• Issue: 2
• DOI: https://doi.org/10.1111/bjd.14208
• Public URL: https://nottingham-repository.worktribe.com/output/776421
• Publisher URL: http://onlinelibrary.wiley.com/doi/10.1111/bjd.14208/abstract
• Contract Date: Sep 19, 2017