Turkish Version of the Chronic Urticaria Quality of Life Questionnaire: Cultural Adaptation, Assessment of Reliability and Validity

Abstract

Chronic spontaneous urticaria has a substantial impact on patients’ quality of life. The first disease-specific tool to assess quality of life impairment in this condition, the Chronic Urticaria Quality of Life Questionnaire (CU-Q2oL), was developed recently. The aim of this study was to adapt the original Italian version to the Turkish language and to evaluate its reliability, validity, and sensitivity to change. The Turkish version was developed by performing forward- and back-translation. It was then applied to 140 consecutive patients with chronic spontaneous urticaria, along with the Dermatology Life Quality Index and the Skindex-29. Disease activity was assessed using the Urticaria Activity Score. Sensitivity to change was measured in 101 patients, who completed the instruments twice at intervals of 4 weeks. Confirmatory factor analysis demonstrated that the six-scale structure of the original Italian version (“pruritus”, “swelling”, “impact on life activities”, “sleep problems”, “limits”, “looks”) can be retained in the Turkish instrument. Analysis regarding convergent validity showed good correlations of the Turkish CU-Q2oL with the other instruments. In addition, it was found to discriminate well between patients with different levels of urticaria activity, and to be sensitive to change. In conclusion, the Turkish version of CU-Q2oL is a reliable, valid, and sensitive instrument, which will help to characterize better the clinical impact of chronic spontaneous urticaria and treatment outcomes in Turkish patients. Its identical scale structure to that of other CU-Q2oL instruments makes it ideal for cross-cultural comparisons and for its application in future national and multinational studies.