title: Travel distances, socioeconomic characteristics, and health disparities in nonurgent and frequent use of Hospital Emergency Departments in South Carolina: a population-based observational study.
abstract: BACKGROUND
  Nonurgent use of hospital emergency departments (ED) is a controversial topic. It is thought to increase healthcare costs and reduce quality, but is also considered a symptom of unequal access to health care. In this article, we investigate whether convenience (as proxied by travel distances to the hospital ED and to the closest federally qualified health center) is associated with nonurgent ED use, and whether evidence of health disparities exist in the way vulnerable populations use the hospital ED for medical care in South Carolina.
  
  
  METHODS
  Our data includes 6,592,501 ED visits in South Carolina between 2005 and 2010 from the South Carolina Budget Control Board and Office of Research and Statistics. All ED visits by South Carolina residents with unmasked variables and nonmissing urgency measures, or approximately 76% of all ED visits, are used in the analysis. We perform multivariable linear regressions to estimate correlations between (1) travel distances and observable sociodemographic characteristics and (2) measures of nonurgent ED use or frequent nonurgent ED use, as defined by the New York University ED Algorithm.
  
  
  RESULTS
  Patients with commercial private insurance, self-pay patients, and patients with other payment sources have lower measures of nonurgent ED use the further away the ED facility is from the patients' home address. Vulnerable populations, particularly African American and Medicaid patients, have higher measures of nonurgent ED scores, and are more frequent users of the ED for both nonurgent and urgent reasons in South Carolina. At the same time, African Americans visit the hospital ED for medical conditions with higher primary care-preventable scores.
  
  
  CONCLUSIONS
  Contrary to popular belief, convenient access (in terms of travel distances) to hospital ED is correlated with less-urgent ED use among privately insured patients and self-pay patients in South Carolina, but not publicly insured patients. Unequal access to primary care appears to exist, as suggested by African American patients' use of the hospital ED for primary care-treatable conditions while experiencing more frequent and more severe primary care-preventable conditions.
authors.affiliation: Arnold School of Public Health, University of South Carolina, 915 Greene Street Suite 354, Columbia, South Carolina, 29208, USA. bchen@mailbox.sc.edu.
authors.forename: Brian K
authors.initials: BK
authors.lastname: Chen
authors.affiliation: Arnold School of Public Health, University of South Carolina, 915 Greene Street Suite 354, Columbia, South Carolina, 29208, USA. chengximph@gmail.com.
authors.forename: Xi
authors.initials: X
authors.lastname: Cheng
authors.affiliation: School of Medicine, University of South Carolina, Columbia, South Carolina, USA. kevin.bennett@usmed.sc.edu.
authors.forename: Kevin
authors.initials: K
authors.lastname: Bennett
authors.affiliation: Arnold School of Public Health, University of South Carolina, 915 Greene Street Suite 354, Columbia, South Carolina, 29208, USA. hibbert@mailbox.sc.edu.
authors.forename: James
authors.initials: J
authors.lastname: Hibbert
mesh_terms: D000293:Adolescent; D000328:Adult; D001741:Black or African American; D000368:Aged; D002648:Child; D002675:Child, Preschool; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data*; D005260:Female; D017048:Health Care Costs; D054624:Health Status Disparities; D006801:Humans; D007223:Infant; D016014:Linear Models; D008297:Male; D008484:Medicaid / Q000706:statistics & numerical data; D008875:Middle Aged; D011320:Primary Health Care; D012959:Socioeconomic Factors; D013022:South Carolina; D014195:Travel; D014481:United States; D055815:Young Adult