Rates and Timing of Follow-up Colonoscopy After a Positive Stool-Based Test in an Integrated Health System

BACKGROUND: Completion of follow-up colonoscopy after a positive stool-based test varies across health settings. Colonoscopy performed > 6 months following a positive stool test is associated with adverse colorectal cancer outcomes. METHODS: This retrospective study included 701 patients aged 45-75 in an urban, integrated health system with a positive stool test between February 1, 2022, and January 31, 2023. We examined rates of timely (i.e., within 180 days) follow-up colonoscopy and at varying time points (90 days, 365 days, and any time during our follow-up period). Multivariable Cox proportional hazard models examined factors associated with timely colonoscopy, and a Pareto analysis identified barriers to timely completion. RESULTS: The median age of this cohort was 64 years (IQR 56-70); 52.1% were female, 48.2% were non-Hispanic White, and 52.4% had a Charlson Comorbidity Index score ≥ 3. The rate of timely follow-up colonoscopy was 59.6%, with rates of 44.5% and 68.5% at 90 days and 365 days, respectively. In Cox models, patient outreach increased timely colonoscopy by 52% (HR 1.52, 95% CI 1.21-1.91), while Direct Access patients were less likely to complete timely colonoscopy (HR 0.59, 95% CI 0.41-0.86); no associations were observed with sociodemographic factors. The most common barriers to timely colonoscopy were (1) lack of gastroenterology clinic visit, (2) patient refusal, and (3) colonoscopy no-show or cancellation. CONCLUSIONS: The rate of timely, follow-up colonoscopy in this older, sicker population is suboptimal. System-level factors impact timely completion. A Pareto analysis reveals multiple elements that contribute to delays in colonoscopy and can inform interventions.