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

BackgroundThe 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.ObjectivesTo investigate the risk of AEs requiring hospitalization after screening and nonscreening colonoscopies compared with control subjects who did not undergo colonoscopy.DesignRetrospective matched cohort.SettingStatutory health insurance fund in Germany.PatientsA 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.InterventionsOutpatient screening and nonscreening colonoscopies.Main Outcomes MeasurementsRisk 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.ResultsThe 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.LimitationsThe analysis relies on health insurance claims data.ConclusionsThis 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.