Cultural adaptation and application of the IBS–QOL in China: a disease-specific quality-of-life questionnaire

Background Irritable bowel syndrome (IBS) is a chronic and episodic illness characterized by altered bowel habits and associated abdominal pain. At present, IBS is one of the most common functional gastrointestinal and motility disorders affecting countries around the world. Surveys have found that patients with IBS have a significantly lower health-related quality of life. Objectives The aim of this study was to translate and examine the validity of the Irritable Bowel Syndrome–Quality of Life questionnaire (IBS–QOL) in patients suffering from IBS in China. Methods A structured procedure was used for the translation and cultural adaptation of the original English IBS–QOL into Chinese. The questionnaire was administered to 73 clinical patients with IBS and␣70 healthy individuals. Psychometric testing for reliability, validity and responsiveness followed standardized procedures. Test–retest reliability (10–20 hours) was assessed using the clinical patients. Follow-up (4 weeks) was collected for 61 clinical patients. All enrolled patients also completed the Short Form-36 Health Survey (SF-36) at the baseline visit. Responsiveness to treatment (Venlafaxine and traditional Chinese herbal medicine) was assessed by one-way ANOVA methods. Results The average length of time required to complete the questionnaire was short (5.63 min for IBS patients and 5.54 min for healthy subjects by self-administration). Internal consistency (Cronbach’s alpha) values ranged from 0.722 to 0.914 for the Chinese IBS–QOL subscales and test–retest reliability coefficients were higher than 0.920 on all subscales. The convergent and discriminate validity results comparing the Chinese translation of the IBS–QOL overall score and the SF-36 subscales confirmed our predicted hypotheses. The Chinese IBS–QOL scores are more highly correlated with social functioning, vitality and general health (SF-36) and show weaker associations with physical functioning, role physical, mental health, and bodily pain (SF-36). The Chinese translation of the IBS–QOL was responsive to treatment. Conclusion In general, the Chinese translation of the IBS–QOL, after cultural adaptation and revision, possesses good reliability, validity and responsiveness. It is a reliable and valid instrument to assess the quality of life in Chinese patients suffering from IBS and is an appropriate measure to use in further clinical trials or for related research projects in China.