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. (Gastrointest Endosc 2013;77:419-29.)