BACKGROUND: Vitiligo significantly affects a person's health-related quality of life (HRQL). Although a small number of generic, and disease-specific, dermatologic HRQL measures exist, currently no vitiligo-specific instrument is available to capture disease-targeted concerns and issues. OBJECTIVE: We sought to develop and validate a vitiligo-specific self-report instrument for HRQL. METHODS: A pool of vitiligo-specific items was created based on in-depth interviews with patients with vitiligo (n = 16) and their responses to items in several previously validated HRQL measures. These items comprising our new instrument, VitiQoL, along with Skindex-16 and Dermatology Life Quality Index were administered to patients with vitiligo (n = 90) at two academic centers. This new instrument was validated using psychometric analysis. RESULTS: The VitiQoL items showed high internal consistency (Cronbach alpha = 0.935). Exploratory factor analysis demonstrated 3 factors: participation limitation, stigma, and behavior. Concurrent validity was evidenced by large correlations between self-reported severity and VitiQoL scores (r = 0.51). Known groups validity was demonstrated for the VitiQoL behavior subscale between individuals with exposed and unexposed patches (P = .01). Convergent validity was shown by strong correlations between VitiQoL and outside dermatology scales measuring similar constructs (Skindex-16, r = 0.82; Dermatology Life Quality Index, r = 0.83). LIMITATIONS: Potential selection bias was a limitation as most patients were recruited from academic centers. Reliability of the instrument was tested only with internal consistency and not reproducibility. Responsiveness of the instrument was not tested because of the prolonged time course necessary to observe clinically significant change in vitiligo. CONCLUSION: VitiQoL is a reliable and valid HRQL instrument.
BACKGROUND: Vitiligo significantly affects a person's health-related quality of life (HRQL). Although a small number of generic, and disease-specific, dermatologic HRQL measures exist, currently no vitiligo-specific instrument is available to capture disease-targeted concerns and issues. OBJECTIVE: We sought to develop and validate a vitiligo-specific self-report instrument for HRQL. METHODS: A pool of vitiligo-specific items was created based on in-depth interviews with patients with vitiligo (n = 16) and their responses to items in several previously validated HRQL measures. These items comprising our new instrument, VitiQoL, along with Skindex-16 and Dermatology Life Quality Index were administered to patients with vitiligo (n = 90) at two academic centers. This new instrument was validated using psychometric analysis. RESULTS: The VitiQoL items showed high internal consistency (Cronbach alpha = 0.935). Exploratory factor analysis demonstrated 3 factors: participation limitation, stigma, and behavior. Concurrent validity was evidenced by large correlations between self-reported severity and VitiQoL scores (r = 0.51). Known groups validity was demonstrated for the VitiQoL behavior subscale between individuals with exposed and unexposed patches (P = .01). Convergent validity was shown by strong correlations between VitiQoL and outside dermatology scales measuring similar constructs (Skindex-16, r = 0.82; Dermatology Life Quality Index, r = 0.83). LIMITATIONS: Potential selection bias was a limitation as most patients were recruited from academic centers. Reliability of the instrument was tested only with internal consistency and not reproducibility. Responsiveness of the instrument was not tested because of the prolonged time course necessary to observe clinically significant change in vitiligo. CONCLUSION: VitiQoL is a reliable and valid HRQL instrument.
Authors: Jonathan M Batchelor; Kim S Thomas; Perways Akram; Jaskiran Azad; Anthony Bewley; Joanne R Chalmers; Seau Tak Cheung; Lelia Duley; Viktoria Eleftheriadou; Robert Ellis; Adam Ferguson; Jonathan Mr Goulding; Rachel H Haines; Hamdi Hamad; John R Ingram; Bisola Laguda; Paul Leighton; Nick Levell; Areti Makrygeorgou; Garry D Meakin; Adam Millington; Malobi Ogboli; Amirtha Rajasekaran; Jane C Ravenscroft; Andrew Rogers; Tracey H Sach; Miriam Santer; Julia Stainforth; Wei Tan; Shyamal Wahie; Jennifer White; Maxine E Whitton; Hywel C Williams; Andrew Wright; Alan A Montgomery Journal: Health Technol Assess Date: 2020-11 Impact factor: 4.014