Increasing Age and Comorbidities Heighten Risk of Post-Colonoscopy SAEs

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Several factors, including increasing age and the presence of comorbidities, can increase the risk of serious adverse events following colonoscopy procedure.

Several factors, including increasing age and the presence of comorbidities, can increase the risk of serious adverse events (SAEs) following a screening or primary diagnostic colonoscopy, according to a study in the American Journal of Gastroenterology. The study also found that colonoscopies performed at university hospitals carry higher risks of SAEs.

Researchers included patient data from the Système National des Données de Santé (SNDS) National Health Data System in this cohort study. The SNDS contains health insurance claims for inpatient and outpatient care of approximately 67,000,000 people living in France. Data were obtained from 4,088,799 patients ≥30 years of age who had received their first screening or diagnostic colonoscopy between 2010 and 2015. The median age of patients included in the study was 59 years.

Researchers estimated the rates of cardiovascular and renal SAE in the 5 days following colonoscopy. Standardized incidence ratios (SIRs) were used to compare the incidence rates of SAEs in the study population to those in the general population. Risk factors associated with post-colonoscopy SAEs were also assessed.

The 5-day SAE incidence rates for shock, myocardial infarction (MI), stroke, pulmonary embolism (PE), acute renal failure, and urolithiasis were 2.8 per 10,000 procedures, 0.87 per 10,000 procedures, 1.9 per 10,000 procedures, 2.9 per 10,000 procedures, 5.5 per 10,000 procedures, and 3.3 per 10,000 procedures, respectively. Approximately 5.1% of patients with cardiovascular SAEs had ≥2 SAEs, whereas 4.1% had concomitant gastrointestinal bleeding and 1.3% had concomitant gastrointestinal perforation.

During the 5 days following colonoscopy, SIRs ranged from 3.3 (95% CI, 3.0–3.7) for MI to 15.8 (95% CI, 14.9–16.7) for shock. Following cardiovascular SAEs, the 30-day mortality rates ranged from 55.8 per 1000 cases of PE to 268.1 per 1000 cases of shock. After renal SAEs, the 30-day mortality rates were 192.5 per 1000 cases of acute renal failure and 2.2 per 1000 cases of urolithiasis.

In multivariate analyses, increasing age correlated with a higher risk of SAE. Increasing age was associated with a substantial increase in risk for cardiovascular SAEs, including shock (aged ≥80 years: adjusted odds ratio [aOR], 3.14; 95% CI, 2.21–4.45; P <.0001), MI (aOR, 5.86; 95% CI, 1.80–19.0; P =.0033), stroke (aOR, 4.18; 95% CI, 2.11–8.30; P <.0001), and PE (aOR, 2.99; 95% CI, 2.10–4.26; P <.0001).

Relative to other SAEs, the risks of shock and acute renal failure were associated with a greater number of comorbidities. Colonoscopies performed at university hospitals correlated with significantly increased risks of shock (aOR, 23.5; 95% CI, 14.7–37.6; P <.0001), MI (aOR, 5.72; 95% CI, 3.33–9.81; P <.0001), stroke (aOR, 14.5; 95% CI, 8.82–23.8; P <.0001), PE (aOR, 16.1; 95% CI, 11.1–23.4; P <.0001), acute renal failure (aOR, 9.64; 95% CI, 6.48–14.3; P <.0001), and urolithiasis (aOR, 2.20; 95% CI, 1.36–3.56; P =.0012).

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Limitations of this study included the lack of differentiation between screening and diagnostic colonoscopies as well as the lack of adjustment for sedation methods, which may have impacted SAEs.

The investigators concluded that “colonoscopies performed in patients at increased risk, identified by their age and preexisting conditions, should be closely monitored to detect and treat any systemic SAEs as soon as possible and limit their mortality.”


Laanani M, Weill A, Carbonnel F, et al. Incidence of and risk factors for systemic adverse events after screening or primary diagnostic colonoscopy: a nationwide cohort study. Am J Gastroenterol. 2020;115(4):537-547.