Objective: Health-related quality of life (HRQoL) is an important measure of inflammatory bowel disease (IBD) health outcome. The Inflammatory Bowel Disease Questionnaire (IBDQ) comprising 32 items grouped into four dimensions is a widely used IBD-specific HRQoL instrument. The purpose of this study was to evaluate the validity, reliability and responsiveness of the Swedish translation of the IBDQ in patients with Crohn's disease (CD).
Material and methods: Four hundred and forty-eight patients with CD completed the IBDQ and three other HRQoL questionnaires (Rating Form of IBD Patient Concerns; Short Form-36; and the Psychological General Well-Being Index) in connection with their regular visit at the outpatient clinic. Disease activity was assessed by the physician on a 4-point Likert scale. Thirty-two patients who were stable in remission completed the questionnaires a second time, 4 weeks later. A total of 418 patients repeated all measurements after 6 months.
Results: The dimensional scores were highly correlated with other measures of corresponding aspects of HRQoL and were significantly better in remission than in relapse. High test-retest correlations indicated good reliability. Responsiveness was confirmed in patients whose disease activity changed over time. However, high correlations between the dimensions, poor correlations between items within each dimension, and factor analysis all indicated that the original grouping of the items is not valid for Swedish CD patients.
Conclusions: Although the Swedish IBDQ has good external validity, reliability and responsiveness for patients with CD, our results did not support the original grouping of the items.