title: Cost Differences After Initial CT Colonography Versus Optical Colonoscopy in the Elderly.
abstract: OBJECTIVE
  To compare differences in Medicare costs 1 year after initial computed tomographic colonography (CTC) or initial optical colonoscopy (OC).
  
  
  METHODS
  We performed a retrospective cohort study of asymptomatic Medicare outpatients aged ≥ 66 years who received initial CTC (n = 531) or OC (n = 17,593) between January 2007 and December 2008; initial OC patients were matched on county of residence and year of screening. Outcomes included differences in total inpatient and outpatient Medicare costs 1 year after initial CTC or OC and differences in outpatient testing of potential findings in the colon, abdomen, pelvis, and lungs.
  
  
  RESULTS
  Higher adjusted costs per patient were revealed in the year after initial CTC compared to initial OC for outpatient testing related to potential colonic ($50; 95% confidence interval [CI], $12-$88; P = .010) and extracolonic findings ($64; 95% CI, $23-$106; P = .002). However, there were no differences in adjusted total costs per patient in the year after either modality ($2065; 95% CI, $1672-$5803; P = .28). Similarly, adjusted costs did not differ between cohorts for inpatient ($267; 95% CI, $1017-$1550; P = .68) or outpatient care ($2828; 95% CI, $311-$5966; P = .08).
  
  
  CONCLUSIONS
  Despite higher adjusted costs of outpatient testing potentially related to colonic and extracolonic findings among asymptomatic elderly patients 1 year after initial CTC compared to OC, we found no differences in adjusted total, inpatient, or outpatient costs between cohorts. Although Medicare does not cover screening CTC, our results suggest that these modalities generate comparable downstream costs to payers.
authors.affiliation: Department of Radiology, Hospital of the University of Pennsylvania, 3400 Spruce St, Philadelphia, PA 19104. Electronic address: hanna.zafar@uphs.upenn.edu.
authors.forename: Hanna M
authors.initials: HM
authors.lastname: Zafar
authors.affiliation: American Academy of Dermatology, Schaumburg, Illinois.
authors.forename: Jianing
authors.initials: J
authors.lastname: Yang
authors.affiliation: Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts.
authors.forename: Katrina
authors.initials: K
authors.lastname: Armstrong
authors.affiliation: Department of Medicine, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Peter
authors.initials: P
authors.lastname: Groeneveld
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000553:Ambulatory Care / Q000191:economics; D015331:Cohort Studies; D023881:Colonography, Computed Tomographic / Q000191:economics*; D003113:Colonoscopy / Q000191:economics*; D015179:Colorectal Neoplasms / Q000175:diagnosis* / Q000191:economics* / Q000453:epidemiology; D015577:Geriatric Assessment / Q000706:statistics & numerical data; D017048:Health Care Costs / Q000706:statistics & numerical data; D006760:Hospitalization / Q000191:economics; D006801:Humans; D006278:Medicare / Q000191:economics*; D012189:Retrospective Studies; D014481:United States / Q000453:epidemiology
keywords: Colorectal cancer; gastroenterology; health care costs; health care utilization; radiology