title: Hospital determinants of emergency department left without being seen rates.
abstract: OBJECTIVE
  The proportion of patients who leave without being seen in the emergency department (ED) is an outcome-oriented measure of impaired access to emergency care and represents the failure of an emergency care delivery system to meet its goals of providing care to those most in need. Little is known about variation in the amount of left without being seen or about hospital-level determinants. Such knowledge is necessary to target hospital-level interventions to improve access to emergency care. We seek to determine whether hospital-level socioeconomic status case mix or hospital structural characteristics are predictive of ED left without being seen rates.
  
  
  METHODS
  We performed a cross-sectional study of all acute-care, nonfederal hospitals in California that operated an ED in 2007, using data from the California Office of Statewide Health Planning and Development database and the US census. Our outcome of interest was whether a visit to a given hospital ED resulted in left without being seen. The proportion of left without being seen was measured by the number of left without being seen cases out of the total number of visits.
  
  
  RESULTS
  We studied 9.2 million ED visits to 262 hospitals in California. The percentage of left without being seen varied greatly over hospitals, ranging from 0% to 20.3%, with a median percentage of 2.6%. In multivariable analyses adjusting for hospital-level socioeconomic status case mix, visitors to EDs with a higher proportion of low-income and poorly insured patients experienced a higher risk of left without being seen. We found that the odds of an ED visit resulting in left without being seen increased by a factor of 1.15 for each 10-percentage-point increase in poorly insured patients, and odds of left without being seen decreased by a factor of 0.86 for each $10,000 increase in household income. When hospital structural characteristics were added to the model, county ownership, trauma center designation, and teaching program affiliation were positively associated with increased probability of left without being seen (odds ratio 2.09; 1.62, and 2.14, respectively), and these factors attenuated the association with insurance status.
  
  
  CONCLUSIONS
  Visitors to different EDs experience a large variation in their probability of left without being seen, and visitors to hospitals serving a high proportion of low-income and poorly insured patients are at disproportionately higher risk of leaving without being seen. Our findings suggest that there is room for substantial improvement in this outcome, and regional interventions can be targeted toward certain at-risk hospitals to improve access to emergency care.
authors.affiliation: Department of Emergency Medicine, University of California, San Francisco, CA, USA. rhsia@sfghed.ucsf.edu
authors.forename: Renee Y
authors.initials: RY
authors.lastname: Hsia
authors.forename: Steven M
authors.initials: SM
authors.lastname: Asch
authors.forename: Robert E
authors.initials: RE
authors.lastname: Weiss
authors.forename: David
authors.initials: D
authors.lastname: Zingmond
authors.forename: Li-Jung
authors.initials: LJ
authors.lastname: Liang
authors.forename: Weijuan
authors.initials: W
authors.lastname: Han
authors.forename: Heather
authors.initials: H
authors.lastname: McCreath
authors.forename: Benjamin C
authors.initials: BC
authors.lastname: Sun
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D002140:California; D016009:Chi-Square Distribution; D003953:Diagnosis-Related Groups; D004636:Emergency Service, Hospital; D006297:Health Services Accessibility / Q000706:statistics & numerical data*; D006761:Hospitals / Q000706:statistics & numerical data*; D006801:Humans; D007182:Income; D008297:Male; D017057:Medically Uninsured / Q000706:statistics & numerical data; D008913:Minority Groups / Q000706:statistics & numerical data; D015999:Multivariate Analysis; D011203:Poverty; D012189:Retrospective Studies; D012959:Socioeconomic Factors