Importance: The benefits from colorectal cancer (CRC) screening may take 10 to 15 years to accrue. Therefore, screening is recommended for older adults who are in good health.
Objective: To determine the number of screening colonoscopies done in patients older than 75 years with a life expectancy of fewer than 10 years, diagnostic yield, and associated adverse events within 10 days and 30 days of the procedure.
Design: This cross-sectional study with a nested cohort between January 2009 and January 2022 in an integrated health system assessed asymptomatic patients older than 75 years who underwent screening colonoscopy in the outpatient setting. Reports with incomplete data, any indication other than screening, patients who had a colonoscopy within the previous 5 years, and patients with a personal history of inflammatory bowel disease or CRC were excluded.
Exposures: Life expectancy based on a prediction model from previous literature.
Main outcomes and measures: The primary outcome was the percentage of screened patients who had limited (<10 years) life expectancy. Other outcomes included colonoscopy findings and adverse events that developed within 10 days and 30 days of the procedure.
Results: A total of 7067 patients older than 75 years were included. The median (IQR) age was 78 (77-79) years, 3967 (56%) were women, and 5431 (77%) were White with an average of 2 comorbidities (taken from a select group of comorbidities). The proportion of colonoscopies performed on patients with a life expectancy of fewer than 10 years aged 76 to 80 years was 30% in both sexes and increased with age-82% of men and 61% of women aged 81 to 85 years (71% total), and 100% of patients beyond the age of 85 years. Adverse events requiring hospitalizations were common at 10 days (13.58 per 1000) and increased with age, particularly among patients older than 85 years. The detection of advanced neoplasia varied from 5.4% among patients aged 76 to 80 years to 6.2% in those aged 81 to 85 years and 9.5% among patients older than 85 years (P = .02). Of the total population, 15 patients (0.2%) had invasive adenocarcinoma; among patients with a life expectancy of fewer than 10 years, 1 of 9 was treated, whereas 4 of 6 patients with a life expectancy of greater than or equal to 10 years were treated.
Conclusions and relevance: In this cross-sectional study with a nested cohort, most screening colonoscopies performed in patients older than 75 years were in patients with limited life expectancy and associated with increased risk of complications. Colorectal cancer was exceedingly rare.