Analysis of Adequacy of Bowel Preparation in Patients Receiving Onsite Dosing

Abstract

Introduction: Split dose bowel preparation has been shown to be superior to same day or previous day preparation and has been associated with higher adenoma detection rates and improved patient tolerance. The aim of the study was to evaluate bowel prep quality and factors impacting it in patients undergoing onsite split dosing. Methods: Data was retrospectively collected from an endoscopy database of a single large tertiary referral center of adult patients who underwent colonoscopy from January 2005 to November 2015. Patient demographics (age, race, gender, BMI, use of medications), data about presence of comorbidities and colonoscope type (standard definition, high-definition) were collected. Bowel preparation was defined as adequate if it was scored as good or excellent and inadequate if it was poor or fair. Redo colonoscopy was defined as a repeat colonoscopy within 6-12 months from preceding colonoscopy due to inadequate mucosal visualization. For univariate analysis, continuous variables were compared using Student's T-test and categorical variables were compared using chi-square or Fisher's exact test. Multivariate analysis was done using logistic regression model. Results: A total of 2138 patients who underwent 2893 colonoscopies were included in the study. The mean age of the patients was 66.3 years and 95.6% of them were males. Bowel preparation was inadequate in 214 (7.4%) patients. The demographics of the patients in both groups (adequate vs. inadequate prep) are listed in Table 1. Patients with an inadequate bowel preparation had significant lower adenoma detection rates (49.5% vs 63.4%, p<0.001); total number of adenomas removed (1.5 ± 2.7 vs. 1.9 ± 2.4; p<0.001) and cecal intubation rates (93.5% vs. 98.1%; p< 0.001). On multivariate analysis after adjusting for age, gender, and race, the presence of cirrhosis is associated with a higher risk of inadequate bowel preparation (OR 2.75, 95% CI 1.1-6.87, p=0.031). The odds of having a redo colonoscopy with inadequate prep was nearly twice as that with adequate preparation (OR 1.95, OR 1.15-3.31, p=0.014). Conclusion: Use of an onsite split dose bowel prep is associated with only 7% overall inadequate bowel preps, with 93% of the preps being either good or excellent. Inadequate bowel preps are associated with lower ADRs, adenomas removed and cecal intubation rates and higher colonoscopy re do rates. Cirrhosis appears to be a risk factor for inadequate bowel prep.2764_A Figure 1. Demographic variables, redo rates and quality indicators2764_B Figure 2. Multivariate logistic regression for predictors of inadequate bowel preparation