The Japanese Version of Skindex‐16: A Brief Quality‐of‐Life Measure for Patients with Skin Diseases

A practical quality‐of‐life measure applicable to patients with skin diseases is necessary. Recently developed dermatological quality‐of‐life measures must be translated and adapted for use in cultures other than the ones in which they were created. In this study, we translated and adapted culturally into Japanese a skin‐disease‐specific, brief quality‐of‐life measure, Skindex‐16, and studied its reliability and validity. Forward‐and back‐translations of Skindex‐16 were carried out. Six doubtful items as well as the term “skin condition” required a second forward‐ and back‐translation to reach satisfactory agreement with the original instrument. Cross‐cultural adaptation and cross‐sectional questionnaire studies were then performed to evaluate the reliability and validity of the instrument. One hundred patients and 30 healthy adults responded to the Japanese version. The internal‐consistency reliability of the final Japanese version of Skindex‐16 was high (range of Cronbach's alpha for each scale, symptoms, emotions, and functioning, was 0.83–0.92). The Japanese version showed construct and content validity. As hypothesized, scores for dermatological patients were higher than those for healthy persons (mean global scores 36 ± 23 vs 1 ± 2, p < 0.001) and scores for patients with inflammatory diseases were higher than those for patients with isolated skin lesions (mean global scores 48 ± 21 vs 22 ± 17, p < 0.001), indicating a poorer quality of life. Most patients' responses to an open‐ended question about their skin disease were similar to those of the American responders and were addressed according to the items. In conclusion, we have developed a semantically equivalent translation of Skindex‐16 into Japanese. It is a reliable and valid measure of the effects of skin disease on the quality of life in Japanese patients.