Food-related Quality of Life in patients with Inflammatory Bowel Disease: Translation and Validation of the German version of FR-QoL-29

The psychosocial effects of eating and drinking - summarized as food-related quality of life (FR-QoL) - are underexplored in inflammatory bowel disease (IBD). Currently, there is no German instrument to assess FR-QoL in IBD patients. This study aimed to translate the validated English FR-QoL-29 questionnaire into German and evaluate its validity and reliability.A monocentric, cross-sectional study was conducted at a tertiary referral center with IBD patients and healthy controls. Participants completed questionnaires on sociodemographics, disease history, the Malnutrition Universal Screening Tool (MUST), the German Short Health Scale (SHS), and the FR-QoL-29-German. The FR-QoL-29 was translated into German using a forward-backward method. Its reliability and validity was assessed using Pearson correlation coefficients, intraclass correlation coefficients, and Cronbach's α.N=200 IBD patients (Crohn's disease: 61.8%; women: 50.8%; remission: 56.2%) and n=10 healthy controls completed the questionnaires. Overall, 113 IBD patients repeated the questionnaires after an average of six weeks. Significant differences in FR-QoL-29-German sum scores were found between all levels of IBD disease activity, except for remission - mild disease (p = 0.423) and moderate - severe disease (p = 0.999). FR-QoL-29-German scores significantly correlated with age (p = 0.041), disease activity (p < 0.001), MUST (p = 0.015), fecal Calprotectin (p = 0.011) and SHS (p < 0.001). Overall, the FR-QoL-29-German showed excellent internal consistency (Cronbach's α = 0.965) and good test-retest reliability (ICC = 0.85 [95% CI: 0.78-0.89]).The FR-QoL-29-German is a valid and reliable tool for assessing food-related quality of life in German-speaking individuals with IBD.