Résumé
Objective:To establish a nomogram to evaluate the adequacy of bowel preparation before colonoscopy and to guide clinical decision-making.Methods:A total of 1 023 valid questionnaires from subjects who underwent diagnosis and treatment of colonoscopy at the digestive endoscopy center, Xiangya Hospital, Central South University from September 2020 to March 2021 were finally returned. The contents of the questionnaire mainly included the clinical characteristics, defecation habits, the number of defecation and the time of the last defecation after taking the medicine and the self-assessment results of bowel preparation before colonoscopy. Subjects' bowel preparation was graded with the Boston bowel preparation scale (BBPS) by a designated endoscopist in a single blinded method. Multivariate analyse was used to explore the influencing factors for bowel preparation adequacy, and a nomogram was drawn accordingly.Results:Based on BBPS scores, bowel preparation of 674 subjects were adequate and 349 were inadequate. Multivariate analyse identified the number of defecation per week ( OR=1.649,95% CI:1.233-2.204, P=0.001), the number of defecation after medication ( OR=3.963, 95% CI: 1.851-8.485, P<0.001), the time of the last defecation after medication ( OR=5.151, 95% CI: 1.152-23.037, P=0.032), and self-assessment of bowel preparation before examination ( OR=8.284, 95% CI: 2.042-33.601, P=0.003) were influencing factors for the adequacy of bowel preparation for colonoscopy. The area under the receiver operating characteristic curve of assessment of colonoscopic bowel preparation adequacy with nomogram visualization according to influencing factors was 0.913, optimal cutoff value was 0.824, the sensitivity was 0.746, and the specificity was 0.971 under the internal validation cohort. Conclusion:The nomogram based on the number of defecation per week, the number of defecation after medication, the time of the last defecation after medication, and self-assessment of bowel preparation before examination could evaluate the adequacy of bowel preparation before colonoscopy, which is worthy of application.