ACCEPTED: COLORECTAL CANCER PREVENTION
Introduction: Inadequate bowel preparation (IBP) reduces the efficacy of colonoscopy. While it is often necessary to have a repeat colonoscopy in this setting, research has demonstrated that having IBP on index colonoscopy increases the risk of IBP on the second colonoscopy. After adjusting for other factors associated with bowel preparation quality, we identified and assessed the impact of modifiable factors associated with IBP on the second colonoscopy.
Methods: Records of all patients with IBP who underwent at least 2 outpatient colonoscopies in the Cleveland Clinic between Jan 2011 and June 2017 identified. Information about patient demographics, clinical, and colonoscopic factors were obtained. Multivariable logistic regression was performed to identify factors associated with IBP on second colonoscopy. Next using this model, a counter-factual analysis was performed whereby hypothesized changes in the modifiable factors were applied to the study population. The effect of such hypothesized changes on IBP rate was computed.
Results: Overall, N=4,677 outpatients had IBP on the first colonoscopy (50% male, mean age 60 years). On the second colonoscopy, 32% of these patients had IBP. Modifiable factors inversely associated with IBP on the second colonoscopy include: having colonoscopy performed before noon (odds ratio [OR], 0.81; 95% confidence interval [CI], 0.71, 0.94), use of low volume (
Conclusion: In patients who have IBP on initial colonoscopy, scheduling the second colonoscopy in the morning, using low volume bowel preparation, and repeating the colonoscopy the next day were all associated with improved outcomes. Indeed, our model predicts that instituting all of these changes would have resulted in a 15% decrease in the rate of IBP of patients undergoing repeat colonoscopy compared to patients in whom the opposite of these changes was instituted.
© The American College of Gastroenterology 2018. All Rights Reserved.