Older adults have greater risk for complications after colonoscopy, study finds

Patients ages 75 years and older had double the risk of complications in the 30 days after colonoscopy of those ages 50 to 74 years, a recent study found.

Researchers looked at all consecutive adults ages 50 years and older who had outpatient first-time or surveillance colonoscopies in the area of Hamilton, Ontario, Canada, between April 2008 and September 2017. They divided participants from four databases into two cohorts: patients ages 50 to 74 years, who were eligible for colorectal cancer screening, and an older cohort of those ages 75 years and older. Anyone with a history of inflammatory bowel disease or a hereditary colorectal cancer syndrome was excluded. The primary outcome was the cumulative incidence of postcolonoscopy complications, defined as the composite of unplanned hospital admissions or ED visits within 30 days (the definition excluded planned admissions related to the surgical treatment of colorectal cancer). The researchers also looked at the independent factors associated with 30-day postcolonoscopy complications. Results were published June 25 by JAMA Network Open.

After exclusions, the analysis included 38,069 patients (mean age, 65.2 years; 50.0% women), 73.1% having their first colonoscopy. About three-quarters of the sample was in the colorectal cancer screening-eligible cohort (n=30,443 patients; mean age, 61.4 years; 49.7% women), with the remaining 7,626 patients (mean age, 80.5 years; 50.9% women) in the older cohort. Overall, 3.4% had a complication in the 30 days after colonoscopy. The cumulative incidence of complications was significantly higher in patients ages 75 years and older (6.8% vs. 2.6%; P<0.001). The association remained significant in a secondary analysis matching the cohorts by number of comorbidities.

While the overall incidence of postcolonoscopy bleeding was low, it was significantly higher in the older cohort than in the other cohort (0.9% vs. 0.3%; P<0.001). The same was true for cardiovascular complications (1.8% vs. 0.5%; P<0.001). The risk of complications increased steadily with age, particularly starting at age 75 years, with a more pronounced increase after age 80 years. The major independent risk factors for postcolonoscopy complications were liver disease (odds ratio [OR], 4.7; 95% CI, 3.5 to 6.5), congestive heart failure (OR, 3.4; 95% CI, 2.5 to 4.6), smoking history (OR, 3.2; 95% CI, 2.4 to 4.3), age 75 years or older (OR, 2.3; 95% CI, 2.0 to 2.6), and obesity (OR, 2.3; 95% CI, 1.2 to 4.2). A greater number of previous colonoscopies was associated with a significantly lower risk of complications (OR, 0.9; 95% CI, 0.7 to 1.0).

Limitations of the study included its observational design and the inability to obtain more detailed descriptions of the admission diagnoses and baseline comorbidities, the study authors said. They noted that current guidelines provide ambiguous recommendations for colonoscopy in patients older than 75 years, largely due to uncertainty about the benefits past this age. “In accordance with our findings, the decision to perform colonoscopy should be considered carefully in older patients, particularly in the presence of comorbidities,” they concluded.