title: Overuse of preoperative cardiac stress testing in medicare patients undergoing elective noncardiac surgery.
abstract: OBJECTIVE
  To determine the frequency and predictors of cardiac stress testing before elective noncardiac surgery in Medicare patients with no indications for cardiovascular evaluation.
  
  
  BACKGROUND
  The American College of Cardiology/American Heart Association guidelines indicate that patients without class I (American Heart Association high risk) or class II cardiac conditions (clinical risk factors) should not undergo cardiac stress testing before elective noncardiac, nonvascular surgery.
  
  
  METHODS
  We used 5% Medicare inpatient claims data (1996-2008) to identify patients aged ≥ 66 years who underwent elective general surgical, urological, or orthopedic procedures (N = 211,202). We examined the use of preoperative stress testing in the subset of patients with no diagnoses consistent with cardiac disease (N = 74,785). Bivariate and multivariate analyses were used to identify predictors of preoperative cardiac stress testing.
  
  
  RESULTS
  Of the patients with no cardiac indications for preoperative stress testing, 3.75% (N = 2803) received stress testing in the 2 months before surgery. The rate of preoperative stress testing increased from 1.72% in 1996 to 6.44% in 2007 (P < 0.0001). A multivariate analysis adjusting for patient and hospital characteristics showed a significant increase in preoperative stress testing over time. Female sex [odds ratio (OR) 1.11; 95% CI: 1.02-1.21], presence of other comorbidities [OR 1.22; 95% confidence interval (CI): 1.09-1.35], high-risk procedure (OR 2.42; 95% CI: 2.04-2.89), and larger hospital size (OR 1.17; 95% CI: 1.03-1.32) were positive predictors of stress testing. Patients living in regions with greater Medicare expenditures (OR 1.24; 95% CI: 1.05-1.45) were also more likely to receive stress tests.
  
  
  CONCLUSIONS
  In a 5% sample of Medicare claims data, 2803 patients underwent preoperative stress testing without any indications. When these results were applied to the entire Medicare population, we estimated that there are over 56,000 patients who underwent unnecessary preoperative stress testing. The rate of testing in patients without cardiac indications has increased significantly over time.
authors.affiliation: Department of Surgery, The University of Texas Medical Branch, Galveston, TX 77555, USA. kmsheffi@utmb.edu
authors.forename: Kristin M
authors.initials: KM
authors.lastname: Sheffield
authors.forename: Patricia S
authors.initials: PS
authors.lastname: McAdams
authors.forename: Jaime
authors.initials: J
authors.lastname: Benarroch-Gampel
authors.forename: James S
authors.initials: JS
authors.lastname: Goodwin
authors.forename: Casey A
authors.initials: CA
authors.lastname: Boyd
authors.forename: Dong
authors.initials: D
authors.lastname: Zhang
authors.forename: Taylor S
authors.initials: TS
authors.lastname: Riall
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D017558:Elective Surgical Procedures; D005080:Exercise Test / Q000706:statistics & numerical data* / Q000639:trends; D005260:Female; D019983:Guideline Adherence / Q000706:statistics & numerical data* / Q000639:trends; D006801:Humans; D008297:Male; D006278:Medicare; D015233:Models, Statistical; D015999:Multivariate Analysis; D017410:Practice Guidelines as Topic; D011300:Preoperative Care / Q000379:methods* / Q000639:trends; D012189:Retrospective Studies; D014481:United States; D019564:Unnecessary Procedures / Q000706:statistics & numerical data* / Q000639:trends