Receipt of Colonoscopy Following Diagnosis of Advanced Adenomas: An Analysis within Integrated Healthcare Delivery Systems

Background: To reduce colorectal cancer incidence and mortality, experts recommend surveillance colonoscopy 3 years after advanced adenoma removal. Little is known about adherence to that interval. Methods: We describe patterns of and factors associated with subsequent colonoscopy among persons with ≥3 adenomas and/or ≥1 adenoma with villous/tubulovillous histology in four U.S. integrated healthcare delivery systems. We report Kaplan–Meier estimators of the cumulative percentage of patients undergoing colonoscopy 6 months to 3.5 years after an index colonoscopy with high-risk findings. Combining data from three healthcare systems, we used multivariable logistic regression with inverse probability of censoring weights to estimate ORs and 95% confidence intervals (CI) for associations between patient characteristics and receipt of subsequent colonoscopy. Results: Among 6,909 persons with advanced adenomas, the percent receiving a subsequent colonoscopy 6 months to 3.5 years later ranged from 18.3% (95% CI: 11.7%–27.8%) to 59.5% (95% CI: 53.8%–65.2%) across healthcare systems. Differences remained significant in the multivariable model. Patients with ≥3 adenomas were more likely than those with 1 to 2 villous/tubulovillous adenomas to undergo subsequent colonoscopy. Subsequent colonoscopy was also more common for patients ages 60–74 and less common for patients ages 80 to 89 compared with those ages 50 to 54 years at their index colonoscopy. Sex, race/ethnicity, and comorbidity index score were generally not associated with subsequent colonoscopy receipt. Conclusions: Colonoscopy within the recommended interval following advanced adenoma was underutilized and varied by healthcare system, age, and number of adenomas. Impact: Strategies to improve adherence to surveillance colonoscopy following advanced adenomas are needed. Cancer Epidemiol Biomarkers Prev; 1–8. ©2018 AACR.