Further validation of the IBS-QOL: A disease-specific quality-of-life questionnaire

OBJECTIVE: There has been growing interest in the investigation of health-r elated quality of life (HRQOL) among patients with gastrointestinal (GI) di sorders. We recently reported on the development and preliminary validation of the IBS-QOL, a specific quality-of-life measure for irritable bowel syn drome (IBS). The aim of this study was to determine the longitudinal constr uct validity (responsiveness) of the IBS-QOL. METHODS: Female patients enrolled in a multicenter treatment trial for func tional bowel disorders were studied pre- and posttreatment with the IBS-QOL and other health status measures. Based on the response to treatment for s everal variables (pain/14-day score, daily function, and days in bed/3 mont hs), patients were stratified into Responders, Partial Responders, and Nonr esponders. Change scores in the IBS-QOL were then statistically compared wi th changes in the other variables to determine their correlation and whethe r Responders were significantly different from non- and Partial Responders on the IBS-QOL. RESULTS: There was a significant correlation between change scores on the I BS-QOL and the other measures of treatment effect (Pain/14 days, r = 0.25, p < 0.002; Sick ness Impact Profile [STP] Total Score, r = 0.28, p < 0.0004 ). In addition, the IBS-QOL scores significantly differentiated Responders from Nonresponders for most of the variables tested (regression trend test for Pain/l4 days, p < 0.04; SIP Total, p < 0.0001; SIP Physical, p < 0.0001 ; SIP Psychosocial, p < 0.002, and SIP Eating, p < 0.04). CONCLUSION: The IBS-QOL is responsive to treatment in a referral-based clin ical population of patients with functional bowel disorders. (C) 2000 by Am . Cell. of Gastroenterology.