title: Variations in ambulance use in the United States: the role of health insurance.
abstract: OBJECTIVE
  The purpose of this study was to describe the associations between individual health insurance and ambulance utilization using a national sample of patients who receive emergency department (ED) care.
  
  
  METHODS
  The data source was the National Hospital Ambulatory Medical Care Survey, years 2004 through 2006. Noninstitutionalized patients between ages 18 and 65 years were included. The primary dependent variable was ambulance use. Multivariable logistic regression methods were used to assess the associations between health insurance status and ambulance use and to adjust for confounders.
  
  
  RESULTS
  A total of 61,013 ED visits were included, representing a national sample of approximately 70 million annual ED visits over 3 years. Ambulance transport was used in 11% of private insurance visits, 16% of Medicaid visits, and 13% of uninsured visits. In the adjusted model, visits by patients with Medicaid (adjusted odds ratio [aOR] = 1.60, 99% confidence interval (CI) = 1.37 to 1.86) and the uninsured (aOR = 1.43, 99% CI = 1.23 to 1.66) were more likely to arrive by ambulance than visits by patients with private insurance. Ambulance use among the uninsured was most pronounced in metropolitan areas.
  
  
  CONCLUSIONS
  Ambulance use varies by health insurance status. Medicaid coverage and lack of insurance are each independently associated with increased odds of ambulance use, suggesting a disproportionate role for emergency medical services (EMS) in the care of patients with limited financial resources.
authors: Robert Wood Johnson Foundation Clinical Scholars Program, the Leonard Davis Institute of Health Economics, the Department of Emergency Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, USA. Zachary.Meisel@uphs.upenn.edu
authors: Zachary F
authors: ZF
authors: Meisel
authors: Jesse M
authors: JM
authors: Pines
authors: Daniel
authors: D
authors: Polsky
authors: Joshua P
authors: JP
authors: Metlay
authors: Mark D
authors: MD
authors: Neuman
authors: Charles C
authors: CC
authors: Branas
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000552:Ambulances / Q000706:statistics & numerical data*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D019458:Insurance Coverage; D007348:Insurance, Health / Q000191:economics*; D016015:Logistic Models; D008297:Male; D008484:Medicaid / Q000191:economics; D017057:Medically Uninsured / Q000706:statistics & numerical data; D008875:Middle Aged; D014481:United States