Impact of antithrombotic therapy on colonoscopy outcomes in FIT-positive patients: implications for polyp detection, diverticulosis and normal findings.

OBJECTIVE

Faecal immunochemical test (FIT) is widely used in colorectal cancer (CRC) screening, but the impact of antithrombotic therapy on colonoscopy outcomes remains unclear. This study aimed to compare polyp detection rate (PDR) and prevalence of non-neoplastic findings in FIT-positive patients undergoing colonoscopy, stratified by antithrombotic therapy.

METHODS

We conducted a retrospective, multicentre cohort study of 26 280 FIT-positive colonoscopies performed between 2016 and 2023 across seven gastroenterology centres in Israel. The FIT positivity threshold was 75 ng/mL. Patients were grouped by therapy: antiplatelets (n=1904), anticoagulants (n=262) or no antithrombotic treatment (n=24 079). Using crude and matched analyses, we assessed PDR, adenoma detection rate (ADR), CRC detection and diverticulosis prevalence.

RESULTS

Patients on antithrombotics were older (mean 65.9±7 vs 61.0±8 years; p<0.001), more often men (65.2% vs 50.1%; p<0.001) and had higher comorbidity rates. Crude PDR was higher in antithrombotic users (55.5% vs 51.9%; p=0.001), but ADR was similar (28.2% vs 28.3%; p=0.950). Diverticulosis was more prevalent in the antithrombotic group (24.0% vs 17.4%; p<0.001). After matching for age and sex (n=2201 pairs), all previously significant associations were eliminated: PDR were no longer different (55.5% vs 53.1%; p=0.112), diverticulosis prevalence became identical (24.0% vs 24.3%; p=0.799) and normal colonoscopy rates were similar (27.5% vs 29.6%; p=0.123). ADRs remained comparable (28.2% vs 26.7%; p=0.269), and CRC detection rates were identical (2.0% vs 2.0%; p=0.998).

CONCLUSION

Demographic confounding, rather than antithrombotic therapy per se, explains the crude associations in colonoscopy outcomes. The matched analysis demonstrates that antithrombotics do not independently affect polyp detection, diverticulosis prevalence or adenoma detection when age and sex are controlled for. These findings support the continued use of antithrombotics during CRC screening, shifting clinical interpretation from medication-based to demographic-based risk stratification.