P477 Performance of bowel preparation quality scales in patients with Crohn’s disease

Abstract

Abstract Background The performance of bowel preparation (BP) in patients with Crohn’s disease (CD) is unknown and may be suboptimal due to the presence of mucosal inflammation, strictures, pseudopolyps and bowel resection. We evaluated the reliability and validity of available BP scales in patients with CD. Methods Bowel preparation, in colonoscopy videos (N=50) from patients with CD (N=40) that represented a range of bowel preparation quality and endoscopic disease activity, was independently rated twice, separated by at least 2 weeks, by 3 central readers using the Boston Bowel Preparation Score (BBPS), modified BBPS, Harefield Cleansing Scale (HCS), Food and Drug Administration bowel cleansing assessment scale (FDA BCAS), and a 100-mm visual analogue scale (VAS) of bowel cleanliness. Endoscopic activity was assessed with the Simple Endoscopic Score for CD (SES-CD). All assessments were on endoscope insertion and withdrawal and in the ileum, right colon, transverse colon, left colon, and rectum to facilitate evaluation of the relationship between BP and SES-CD scores. Reliability of BP assessment was quantified using the intraclass correlation coefficient (ICC) and interpreted with benchmarks defined by Landis and Koch.1 Validity was assessed by within-patient correlation between each BP scale and the VAS across segments using mixed effect models. Correlation between BP quality and SES-SD scores by location was assessed using Spearman’s rho. Results Substantial (ICC ≥0.61) inter-rater reliability was observed for all BP scales and the VAS during insertion and withdrawal, except for the FDA BCAS, which had moderate (ICC ≥0.41) inter-rater reliability on insertion (Table 1). Intra-rater reliability was similarly substantial for all BP scales and almost perfect (ICC ≥0.81) for the VAS during insertion and withdrawal. Coefficients for the validity of all BP scales based on correlation with the VAS of bowel cleanliness exceeded 0.58 on both insertion and withdrawal. BP and endoscopic disease activity were negatively correlated in the colon, particularly in the left colon, suggesting that lower BP scores in this segment may result in higher SES-CD scores (Table 2). Conclusion Existing scales are reliable for the assessment of BP in patients with CD. These results provide a framework for scoring of BP quality in clinical trials for CD and support the inclusion of patients with CD for the evaluation of novel BP agents. Reference: 1. Landis J.R. and Koch G. G. Biometrics. 1977:33;159-74