INITIAL associations between antithrombotic therapy and colonoscopy outcomes appeared to suggest higher detection rates in patients, but further analysis has shown that these differences are not caused by antithrombotic therapy independently, but rather by demographic confounding. Older age, male sex, and higher comorbidity burden in antithrombotic patients contribute significantly to observed differences in colonoscopy findings.
Colonoscopy Outcomes in Patients on Antithrombotic Therapy: A Closer Look at Demographic Effects
Scientists conducted a retrospective, multicentre cohort study of over 26,000 FIT-positive colonoscopies performed in Israel between 2016 and 2023. The FIT positivity threshold was 75 ng/mL, and participants were grouped into three categories: those taking antiplatelet agents (n = 1,904), those on anticoagulants (n = 262), and those not using any antithrombotic therapy (n = 24,079).
In the crude (unadjusted) analysis, patients on antithrombotic therapy were older (mean age 65.9 ± 7 vs 61.0 ± 8 years), more frequently male (65.2% vs 50.1%), and had greater comorbidity. They also showed a higher overall polyp detection rate (PDR; 55.5% vs 51.9%, p = 0.001) and more prevalent diverticulosis (24.0% vs 17.4%, p < 0.001). However, adenoma detection rate and colorectal cancer detection did not differ significantly between groups (ADR 28.2% vs 28.3%; CRC 2.0% vs 2.0%).
To control for demographic confounding, the investigators conducted a matched analysis based on age and sex (2,201 matched pairs). After matching, all previously observed differences disappeared: PDR (55.5% vs 53.1%, p = 0.112), diverticulosis prevalence (24.0% vs 24.3%, p = 0.799), and normal colonoscopy rates (27.5% vs 29.6%, p = 0.123) became statistically indistinguishable. ADRs and CRC detection rates also remained comparable between groups.
Implications for Patients and Doctors
This large-scale analysis provides strong evidence that while antithrombotic therapy may increase FIT positivity due to minor mucosal bleeding, it does not independently affect polyp, adenoma, or colonoscopy cancer detection once demographic differences are accounted for. Clinically, these results support the continued use of antithrombotic therapy during FIT-based CRC screening and encourage clinicians to interpret FIT results and colonoscopy findings based on patient demographics rather than medication status, improving risk stratification and reducing unnecessary interruptions of therapy.
Reference
Abu‑Freha N et al. Impact of antithrombotic therapy on colonoscopy outcomes in FIT‑positive patients: a retrospective multicentre cohort study. BMJ Open Gastroenterology. 2025;12(1):e001922.
