Novel Risk Score for 30-Day Adverse Events Following Colonoscopy in Older Adults

Physicians are challenged with balancing benefits and risks of performing colonoscopies in older adults. We identified adverse event risk factors in this population and developed a predictive risk score for colonoscopy-related adverse events.

From August 2017 to August 2022, 8,154 patients aged ≥60 years who underwent screening or diagnostic colonoscopies were enrolled at Gangnam Severance Hospital. The primary outcome was 30-day adverse events, defined as emergency room visits or unplanned hospitalizations post-colonoscopy. The frailty index calculated via laboratory findings (FI-LAB) was derived from blood test results and vital signs. A risk score was developed and categorized to predict colonoscopy-related adverse events. Data from 9,154 colonoscopies from September 2022 to December 2023 at two tertiary referral hospitals were used for internal and external validation.

The mean age was 67.9 years (range, 60 to 94 years). The 30-day adverse event rate was 1.4%. Adverse events were independently associated with the use of aspirin (adjusted odds ratio [aOR], 2.24), P2Y12 inhibitors (aOR, 1.79), and anticoagulants (aOR, 2.47) and with moderate (aOR, 4.54) and high (aOR, 11.40) FI-LABs. The incidence of adverse events in the low-, moderate-, and high-risk groups were 0.3%, 2.2%, and 10.7%, respectively (p<0.001). The area under the receiver operating characteristic curve for the risk scores were 0.821, 0.856, and 0.757 for the derivation, internal, and external cohorts, respectively.

Colonoscopy-related adverse events in older adults were linked to frailty and medication use and were not dependent on age. This novel risk score supports personalized decision-making when performing colonoscopies in older adults.