VALIDation of the IBD-Disk instrument for assessing disability in Inflammatory Bowel Diseases in a French cohort: the VALIDate study.

BACKGROUND AND AIMS: Inflammatory bowel diseases (IBD) are disabling disorders. The IBD-Disability Index (IBD-DI) was developed for quantifying disability in IBD patients but is difficult to use. The IBD-Disk is a visual adaptation of the IBD-DI. It has not been validated yet. The main objectives were to validate the IBD-Disk, to assess the clinical factors associated with a change in the score and its variability over time. METHODS: From May 2018 to July 2019, IBD patients from three university-affiliated hospitals responded twice to both IBD-Disk and IBD-DI at 3-12 months intervals. Validation included concurrent validity, reproducibility, and internal consistency. Mean IBD-Disk scores were compared according to clinical factors. Variability was assessed by comparing scores between baseline and follow-up visits. RESULTS: A total of 447 patients (71% Crohn's disease, 28% ulcerative colitis) were included in the analysis at baseline and 265 at follow-up. There was a good correlation between IBD-Disk and IBD-DI (r = 0.75, p <0.001). Reproducibility was excellent (intra-class correlation coefficient = 0.90), as well as internal consistency (Cronbach's α = 0.89). The IBD-Disk was not influenced by IBD type but was associated with female gender and physician global assessment. Extra-intestinal manifestations, history of resection, elevated CRP and fecal calprotectin also tended to be associated with higher disability. The IBD-Disk score decreased in patients becoming inactive over time. CONCLUSIONS: This study validated the IBD-Disk in a large cohort of IBD patients, demonstrating that it is a valid and reliable tool for quantifying disability for both CD and UC.