Medicare Under Age 65 and Medicaid Patients Have Poorer Bowel Preparations: Implications for Recommendations for an Early Repeat Colonoscopy

Colonoscopy is performed on patients across a broad spectrum of demographic characteristics. These characteristics may aggregate by patient insurance provider and influence bowel preparation quality and the prevalence of adenomas. The purpose of this study was to evaluate the association of insurance status and suboptimal bowel preparation, recommendation for an early repeat colonoscopy due to suboptimal bowel preparation, adenoma detection rate (ADR), and advanced ADR (AADR). This is a cohort study of outpatient colonoscopies (n = 3113) at a single academic medical center. Patient insurance status was categorized into five groups: 1) Medicare < 65y; 2) Medicare ≥ 65y; 3) Tricare/VA; 4) Medicaid/Colorado Indigent Care Program (CICP); and 5) commercial insurance. We used multivariable logistic or linear regression modeling to estimate the risks for the association between patient insurance and suboptimal bowel preparation, recommendation for an early repeat colonoscopy due to suboptimal bowel preparation, ADR, and AADR. Models were adjusted for appropriate covariates. Medicare patients < 65y (OR 4.91; 95% CI: 3.25-7.43) and Medicaid/CICP patients (OR 4.23; 95% CI: 2.65-7.65) were more likely to have a suboptimal preparation compared to commercial insurance patients. Medicare patients < 65y (OR 5.58; 95% CI: 2.85-10.92) and Medicaid/CICP patients (OR 3.64; CI: 1.60-8.28) were more likely to receive a recommendation for an early repeat colonoscopy compared to commercial insurance patients. Medicare patients < 65y had a significantly higher adjusted ADR (OR 1.50; 95% CI: 1.03-2.18) and adjusted AADR (OR 1.99; 95% CI: 1.15-3.44) compared to commercial insurance patients. Understanding the reasons for the higher rate of a suboptimal bowel preparation in Medicare < 65y and Medicaid/CICP patients and reducing this rate is critical to improving colonoscopy outcomes and reducing healthcare costs in these populations.