Food-related Quality of Life in Inflammatory Bowel Disease: Development and Validation of a Questionnaire

Background: Psychosocial factors surrounding eating and drinking, such as enjoying food, managing restrictions, and maintaining social relationships, remain under-researched in inflammatory bowel disease [IBD]. This study aimed to develop and validate a food-related quality of life [FR-QoL] questionnaire to systematically measure these issues in the IBD population. Methods: Following semi-structured interviews with 28 IBD patients, 150 potential questionnaire items were generated. These were ranked by 100 IBD patients, and items were removed based on ceiling/floor effects and high inter-item correlations [>0.7], with 41 items being retained. In total, 323 IBD patients, 100 asthma patients [chronic disease control], and 117 healthy controls completed the FR-QoL questionnaire, alongside generic and disease-specific QoL and food satisfaction questionnaires. Principal components analysis [PCA], construct and discriminant validity, and test-retest reliability were calculated. Results: Twelve items were removed following PCA. The reduced questionnaire [FR-QoL-29] explained 63.9% of the variance [Cronbach's alpha = 0.96]. FR-QoL-29 correlated significantly with generic QoL [r = 0.697], depression [r = -0.519], anxiety [r = -0.531], and food satisfaction [r = 0.701]. The FR-QoL-29 sumscores were significantly lower for IBD (89.5, standard deviation [SD] 28.6) than asthma [125.4, SD 24.1; p < 0.001] and healthy volunteers [123.0, SD 16.5; p < 0.001]. Within IBD, worse food-related QoL was found in those with moderate/high disease activity [66.7, SD 22.1] compared with remission/low disease activity [92.5, SD 28.1]. Test-retest reliability was good (intra-class correlation [ICC] = 0.83, 95% confidence interval [CI] = 0.76: 0.88). Conclusions: The FR-QoL-29 shows good reliability and validity across a range of IBD characteristics. This easily administered questionnaire is a useful tool in identifying poor food-related QoL and in the future may identify areas for intervention.