Reliability and validity of the Chinese version of the autoimmune bullous disease quality of life (ABQOL) questionnaire

BACKGROUND The autoimmune bullous diseases quality of life (ABQOL) questionnaire was recently developed by an Australian group and has been validated in Australian and North American patient cohorts. It is a 17-item, multidimensional, self-administered English questionnaire. The study aimed to validate the Chinese version of the ABQOL questionnaire and evaluate the reliability in Chinese patients. METHODS The Chinese version of the ABQOL questionnaire was produced by forward-backward translation and cross-cultural adaptation of the original English version. The ABQOL questionnaire was then distributed to a total of 101 patients with autoimmune bullous diseases (AIBDs) together with the Dermatology Life Quality Index (DLQI) and the 36-item Short Form Health Survey (SF-36). Validity was analyzed across a range of indices and reliability was assessed using internal consistency and test-retest methods. RESULTS The Chinese version of the ABQOL questionnaire has a high internal consistency (Cronbach's alpha coefficient, 0.88) and test-retest reliability (the intraclass correlation coefficient, 0.87). Face and content validity were satisfactory. Convergent validity testing showed that the correlation coefficients for the ABQOL and DLQI was 0.77 and for the ABQOL and SF-36 was -0.62. In terms of discriminant validity, there was no significant difference between the proportions of insensitive items in ABQOL and DLQI (p = 0.236). There was no significant difference between the proportions of insensitive items in ABQOL and SF-36 (p = 0.823). CONCLUSIONS The Chinese version of the ABQOL questionnaire has adequate validity and reliability. It may constitute a useful instrument to measure disease burden in Chinese patients with AIBDs.