Food-Related Quality of Life in Inflammatory Bowel Disease: Translation and Validation of Food-Related Quality of Life to the Portuguese Language (FR-QoL-29-Portuguese)

Introduction: Food-related quality of life (FR-QoL) has been shown to be an important patient-reported outcome in inflammatory bowel disease (IBD). We aimed to translate and validate a Portuguese version of the FR-QoL-29. Methods: This was a case-control cross-sectional study undertaken at a tertiary hospital. After obtaining the original authors’ authorization, both forward and backward translations of the original FR-QoL-29 were performed by bilingual researchers. After an IBD expert’s revision and the input of a small group of patients, a final version was obtained. Portuguese IBD patients were prospectively recruited from the outpatient clinic of a tertiary hospital and completed the questionnaire at two timepoints (0 and 4 weeks). Reliability (internal consistency, test-retest, and intraclass correlation [ICC]), validity (content and convergent validity, and hypothesis testing using Spearman’s correlations), and responsiveness (Student t tests) were analysed. Results: 239 patients (mean age 50.1 [SD = 15.3 years], 56.5% female) and 87 (36.4%) patients answered the questionnaire at the first and second timepoints, respectively; 126 controls answered the questionnaire. Overall, the FR-QoL-29-Portuguese showed excellent internal consistency (Cronbach’s α = 0.97) and good test-retest reliability (ICC = 0.78 [95% CI: 0.64–0.85]). FR-QoL moderately correlated with health-related quality of life, measured by the SIBDQ-PT (R = 0.49; p < 0.05). Lastly, the questionnaire revealed appropriate responsiveness when patients reported an overall improvement in general well-being (mean improvement 25.88 [SD = 32.50]; p < 0.05). Discussion/Conclusions: We present an adaptation and validation of the FR-QoL-29 tool for Portuguese IBD patients. The FR-QoL-29-Portuguese is a reliable and valid tool shown to be responsive to changes in general well-being.