Outcomes of Screening Colonoscopy in Older Adults: A Large Propensity-Matched Real-World Cohort Study.

Background: The benefits and harms of screening colonoscopy after age 75 remain uncertain. Guidelines endorse individualized decisions given competing risks, but comparative data are limited. Methods: In the TriNetX US Collaborative Network, adults aged 75-90 years with a colorectal cancer screening encounter were matched 1:1 by colonoscopy within 3 months. Outcomes were assessed at 30 days, 1 year, and 5 years. Sensitivity analyses excluded pre-index anemia and, separately, fecal abnormalities and alarm symptoms; subsequent colonoscopy was counted through 5 years. Results: Matched cohorts comprised 58 315 pairs at 30 days, 61 497 at 1 year, and 69 821 at 5 years. Colonoscopy increased polyp detection (HR 4.43 [95% CI 4.15-4.73] at 30 days; 1.88 [1.82-1.95] at 5 years) and colorectal cancer detection (4.56 [3.62-5.74]; 1.78 [1.59-1.98]; all Conclusion: Screening colonoscopy improved polyp and cancer detection but did not reduce 5-year all-cause mortality. The late perforation signal was not explained by more subsequent or therapeutic colonoscopy. Decisions after age 75 should be individualized.