A Hospital-Based Validation Of Vitiligo Impact Scale-22 In A Tertiary Care Hospital In North Karnataka

Abstract

Background Vitiligo is known to have a major psychosocial impact among the sufferers. The psychological impact does not correlate with the extent of the disease. There are various scales (general health indices, dermatology specific indices and vitiligo specific indices) to measure the QOL in patients with vitiligo. Vitiligo impact scale 22 is a recently developed vitiligo specific scale validated among of a group of North Indian patients. Since the effect of vitiligo on QOL in patients may vary depending upon the region, locality, population, social status, level of education and existing beliefs and taboos, it is important to validate VIS-22 in various population. Objective To validate the vitiligo impact scale – 22 in South Indian patients Method It was a hospital based, longitudinal study. One hundred and fifty three patients suffering from vitiligo and 155 controls suffering from other short term skin diseases attending the dermatology out-patient department of a tertiary care hospital were included in this study. Detailed history with respect to the onset and duration of symptoms, any treatment received, recurrence, and pre-existing medical conditions were recorded. Clinical examination of the patient was done to note the type of vitiligo and subsequent repigmentation or worsening of condition over the 12 week study period. All patients were given visual analogue scale, dermatology life quality index, skindex-16 and vitiligo impact scale - 22 to respond at first visit, and subsequently at 2 and 12 weeks. x Results A total of 153 vitiligo patients and 155 controls were enrolled in the study. Among the 153 vitiligo patients who were enrolled in the study, 124 completed the study at the end of 12 weeks. The criterion validity showed strongest correlation with Skindex-16 (r=0.832). The convergent validity evidenced strongest correlation with bothDLQI (r=0.752) and Skindex-16 (r=0.832). Convergent validity showed a strong correlation with emotional and functioning domain of Skindex-16 at baseline (r=0.713 and 0.702 respectively) and at 12 weeks (r=0.770 and 0.789 respectively). An excellent reliability was seen between the scores between baseline and 2 weeks (r=0.954). The VIS-22 scores were found to be responsive at week 12 and a similar trend was noted in VAS, DLQI and Skindex-16. Conclusion VIS-22 is a valid, highly reliable and responsive scale to measure the impairment of QOL among vitiligo patients. The scale has better measurement properties compared to DLQI and Skindex-16 with questions which are specific to vitiligo patients.