title: Cost Analysis of the STONE Randomized Trial: Can Health Care Costs be Reduced One Test at a Time?
abstract: BACKGROUND
  Decreasing the use of high-cost tests may reduce health care costs.
  
  
  OBJECTIVE
  To compare costs of care for patients presenting to the emergency department (ED) with suspected kidney stones randomized to 1 of 3 initial imaging tests.
  
  
  METHODS
  Patients were randomized to point-of-care ultrasound (POC US, least costly), radiology ultrasound (RAD US), or computed tomography (CT, most costly). Subsequent testing and treatment were the choice of the treating physician.
  
  
  METHODS
  A total of 2759 patients at 15 EDs were randomized to POC US (n=908), RAD US, (n=893), or CT (n=958). Mean age was 40.4 years; 51.8% were male.
  
  
  METHODS
  All medical care documented in the trial database in the 7 days following enrollment was abstracted and coded to estimate costs using national average 2012 Medicare reimbursements. Costs for initial ED care and total 7-day costs were compared using nonparametric bootstrap to account for clustering of patients within medical centers.
  
  
  RESULTS
  Initial ED visit costs were modestly lower for patients assigned to RAD US: $423 ($411, $434) compared with patients assigned to CT: $448 ($438, $459) (P<0.0001). Total costs were not significantly different between groups: $1014 ($912, $1129) for POC US, $970 ($878, $1078) for RAD US, and $959 ($870, $1044) for CT. Hospital admissions contributed over 50% of total costs, though only 11% of patients were admitted. Mean total costs (and admission rates) varied substantially by site from $749 to $1239.
  
  
  CONCLUSIONS
  Assignment to a less costly test had no impact on overall health care costs for ED patients. System-level interventions addressing variation in admission rates from the ED might have greater impact on costs.
authors.affiliation: *Center for Healthcare Policy and Research †Department of Public Health Sciences ‡Department of Emergency Medicine, University of California, Davis, Sacramento §Department of Radiology and Biomedical Imaging ∥Radiology Outcomes Research Laboratory ¶Department of Epidemiology, Biostatistics and the Philip R. Lee Institute for Health Policy Studies, University of California, San Francisco, San Francisco, CA.
authors.forename: Joy
authors.initials: J
authors.lastname: Melnikow
authors.forename: Guibo
authors.initials: G
authors.lastname: Xing
authors.forename: Ginger
authors.initials: G
authors.lastname: Cox
authors.forename: Paul
authors.initials: P
authors.lastname: Leigh
authors.forename: Lisa
authors.initials: L
authors.lastname: Mills
authors.forename: Diana L
authors.initials: DL
authors.lastname: Miglioretti
authors.forename: Michelle
authors.initials: M
authors.lastname: Moghadassi
authors.forename: Rebecca
authors.initials: R
authors.lastname: Smith-Bindman
mesh_terms: D000328:Adult; D003365:Costs and Cost Analysis; D004636:Emergency Service, Hospital / Q000191:economics*; D005260:Female; D017048:Health Care Costs / Q000706:statistics & numerical data*; D006760:Hospitalization / Q000191:economics; D006801:Humans; D007669:Kidney Calculi / Q000000981:diagnostic imaging* / Q000191:economics*; D008297:Male; D019095:Point-of-Care Systems / Q000191:economics*; D014057:Tomography, X-Ray Computed / Q000191:economics; D014463:Ultrasonography / Q000191:economics; D014481:United States