title: Adverse events Following Computed Tomographic Colonography compared to Optical Colonoscopy in the Elderly.
abstract: OBJECTIVE
  To evaluate gastrointestinal and cardiovascular adverse event risks associated with optical colonoscopy (OC) among Medicare outpatients who received computed tomography colonography (CTC) as their initial method of colorectal evaluation.
  
  
  METHODS
  Medicare claims were compared between 6,114 outpatients ≥ 66 years who received initial CTC and 149,202 outpatients who received initial OC between January 2007 and December 2008. OC patients were matched on county of residence and year of evaluation. Outcomes included lower gastrointestinal bleeding, gastrointestinal perforation, other gastrointestinal events and cardiovascular events resulting in an emergency department visit or hospitalization within 30 days.
  
  
  RESULTS
  Among 1,000 outpatients undergoing initial CTC, 12.4 experienced lower gastrointestinal bleeding, 0.7 perforation, 18.0 other gastrointestinal events and 45.5 cardiovascular events within 30 days. After multivariate adjustment, risks of lower gastrointestinal bleeding, other gastrointestinal events and cardiovascular events were higher with initial OC than CTC, with or without subsequent OC (OR 1.91 95CI [1.47,2.49], OR 1.35 95CI [1.07,1.69] and OR 1.38 95CI [1.18,1.62], respectively); however, perforation risk did not differ (p=0.10). This pattern is similar in older and symptomatic populations.
  
  
  CONCLUSIONS
  Rates of gastrointestinal bleeding, other gastrointestinal events and cardiovascular events are lower following initial CTC than OC, but rates of perforation do not differ.
authors.affiliation: Department of Radiology Hospital of the University of Pennsylvania 3400 Spruce Street Philadelphia, PA 19104 ; Leonard Davis Institute of Health Economics University of Pennsylvania Colonial Penn Center, 3641 Locust Walk Philadelphia, PA 19104-6218 Philadelphia, United States.
authors.forename: Hanna M
authors.initials: HM
authors.lastname: Zafar
authors.affiliation: Department of Medicine Hospital of the University of Pennsylvania 3400 Spruce Street Philadelphia, PA 19104.
authors.forename: Michael O
authors.initials: MO
authors.lastname: Harhay
authors.affiliation: Department of Medicine Hospital of the University of Pennsylvania 3400 Spruce Street Philadelphia, PA 19104.
authors.forename: Jianing
authors.initials: J
authors.lastname: Yang
authors.affiliation: Department of Medicine Massachusetts General Hospital 55 Fruit Street-GRB 740 Boston, MA 02114.
authors.forename: Katrina
authors.initials: K
authors.lastname: Armstron