Adverse events requiring hospitalization within 30 days after outpatient screening and nonscreening colonoscopies.

BACKGROUND: The incidence of adverse events (AEs) is a crucial factor when colonoscopy is considered for mass screening, but few studies have addressed delayed and non-GI AEs.
OBJECTIVES: To investigate the risk of AEs requiring hospitalization after screening and nonscreening colonoscopies compared with control subjects who did not undergo colonoscopy.
DESIGN: Retrospective matched cohort.
SETTING: Statutory health insurance fund in Germany. PATIENTS: A total of 33,086 individuals who underwent colonoscopy as an outpatient (8658 screening, 24,428 nonscreening) and 33,086 matched controls who did not undergo colonoscopy.
INTERVENTIONS: Outpatient screening and nonscreening colonoscopies. MAIN OUTCOMES MEASUREMENTS: Risk of AEs (perforation, bleeding, myocardial infarction, stroke, splenic injury, and others) requiring hospitalization within 30 days after colonoscopy/index date and risk differences between the group that underwent colonoscopy and the group that did not.
RESULTS: The incidence of perforation was 0.8 (95% confidence interval [CI], 0.3-1.7) and 0.7 (95% CI, 0.4-1.1) per 1000 screening and nonscreening colonoscopies, respectively. Hospitalizations because of bleeding occurred in 0.5 (95% CI, 0.1-1.2) and 1.1 (95% CI, 0.8-1.7) per 1000 screening and nonscreening colonoscopies, respectively. The incidence of myocardial infarction, stroke, and other non-GI AEs was similar in colonoscopy and control groups. No splenic injury was observed. Those with AEs generally had a higher mean age and comorbidity rate than the overall study population. LIMITATIONS: The analysis relies on health insurance claims data.
CONCLUSIONS: This study provides further evidence of the safety of colonoscopy in routine practice with regard to delayed and non-GI AEs. Hospitalizations because of the investigated AEs were uncommon or rare for both screening and nonscreening colonoscopies.