title: Association of coronary CT angiography or stress testing with subsequent utilization and spending among Medicare beneficiaries.
abstract: BACKGROUND
  Coronary computed tomography angiography (CCTA) is a new noninvasive diagnostic test for coronary artery disease (CAD), but its association with subsequent clinical management has not been established.
  
  
  OBJECTIVE
  To compare utilization and spending associated with functional (stress testing) and anatomical (CCTA) noninvasive cardiac testing in a Medicare population.
  
  
  METHODS
  Retrospective, observational cohort study using claims data from a 20% random sample of 2005-2008 Medicare fee-for-service beneficiaries 66 years or older with no claims for CAD in the preceding year, who received nonemergent, noninvasive testing for CAD (n = 282,830).
  
  
  METHODS
  Cardiac catheterization, coronary revascularization, acute myocardial infarction, all-cause mortality, and total and CAD-related Medicare spending over 180 days of follow-up.
  
  
  RESULTS
  Compared with stress myocardial perfusion scintigraphy (MPS), CCTA was associated with an increased likelihood of subsequent cardiac catheterization (22.9% vs 12.1%; adjusted odds ratio [AOR], 2.19 [95% CI, 2.08 to 2.32]; P < .001), percutaneous coronary intervention (7.8% vs 3.4%; AOR, 2.49 [2.28 to 2.72]; P < .001), and coronary artery bypass graft surgery (3.7% vs 1.3%; AOR, 3.00 [2.63 to 3.41]; P < .001). CCTA was also associated with higher total health care spending ($4200 [$3193 to $5267]; P < .001), which was almost entirely attributable to payments for any claims for CAD ($4007 [$3256 to $4835]; P < .001). Compared with MPS, there was lower associated spending with stress echocardiography (-$4981 [-$4991 to -$4969]; P < .001) and exercise electrocardiography (-$7449 [-$7452 to -$7444]; P < .001). At 180 days, CCTA was associated with a similar likelihood of all-cause mortality (1.05% vs 1.28%; AOR, 1.11 [0.88 to 1.38]; P = .32) and a slightly lower likelihood of hospitalization for acute myocardial infarction (0.19% vs 0.43%; AOR, 0.60 [0.37 to 0.98]; P = .04).
  
  
  CONCLUSIONS
  Medicare beneficiaries who underwent CCTA in a nonacute setting were more likely to undergo subsequent invasive cardiac procedures and have higher CAD-related spending than patients who underwent stress testing.
authors.affiliation: Stanford University School of Medicine, Stanford, CA 94305-5405, USA.
authors.forename: Jacqueline Baras
authors.initials: JB
authors.lastname: Shreibati
authors.forename: Laurence C
authors.initials: LC
authors.lastname: Baker
authors.forename: Mark A
authors.initials: MA
authors.lastname: Hlatky
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D006328:Cardiac Catheterization / Q000191:economics / Q000706:statistics & numerical data; D015331:Cohort Studies; D017023:Coronary Angiography / Q000191:economics*; D003324:Coronary Artery Disease / Q000175:diagnosis*; D005080:Exercise Test / Q000191:economics / Q000706:statistics & numerical data; D018588:Fee-for-Service Plans; D005260:Female; D005102:Health Expenditures / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D006278:Medicare / Q000191:economics* / Q000706:statistics & numerical data; D009026:Mortality / Q000639:trends; D009203:Myocardial Infarction / Q000191:economics; D055414:Myocardial Perfusion Imaging; D009204:Myocardial Revascularization / Q000191:economics / Q000706:statistics & numerical data; D010045:Outpatients; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000191:economics*; D014481:United States