title: Association between primary care practice characteristics and emergency department use in a medicaid managed care organization.
abstract: BACKGROUND
  Many patients use emergency departments (EDs) for primary care. Previous studies have found that patient characteristics affect ED utilization. However, such studies have led to few policy changes.
  
  
  OBJECTIVE
  We sought to determine whether Medicaid patients' ED use is associated with characteristics of their primary care practices.
  
  
  METHODS
  This was a cohort study.
  
  
  METHODS
  A total of 57,850 patients, assigned to 353 primary care practices affiliated with a Medicaid HMO, were included.
  
  
  METHODS
  Predictor variables were characteristics of primary care practices, which were measured by visiting each practice. The outcome variable was ED use adjusted for patient characteristics.
  
  
  RESULTS
  On average, patients made 0.80 ED visits/person/yr. Patients from practices with more than 12 evening hours/wk used the ED 20% less than patients from practices without evening hours. A higher ratio of the number of active patients per clinician-hour of practice time was associated with more ED use. When more Medicaid patients were in a practice, these patients used the ED more frequently. Other factors associated with ED use included equipment for the care of asthma and presence of nurse practitioners and physician assistants.
  
  
  CONCLUSIONS
  Modifiable characteristics of primary care practices were associated with ED use. Because the observational design of this study does not allow definitive conclusions about causality, future studies should include intervention trials to determine whether changing practice characteristics can reduce ED use.
  
  
  CONCLUSIONS
  Improving primary care access and scope of services may reduce ED use. Focusing on systems issues rather than patient characteristics may be a more productive strategy to improve appropriate use of emergency medical care.
authors: Center for Policy and Research in Emergency Medicine, Oregon Health and Science University, Portland, Oregon 97239, USA. lowero@ohsu.edu
authors: Robert A
authors: RA
authors: Lowe
authors: A Russell
authors: AR
authors: Localio
authors: Donald F
authors: DF
authors: Schwarz
authors: Sankey
authors: S
authors: Williams
authors: Lucy Wolf
authors: LW
authors: Tuton
authors: Staci
authors: S
authors: Maroney
authors: David
authors: D
authors: Nicklin
authors: Neil
authors: N
authors: Goldfarb
authors: Deneen D
authors: DD
authors: Vojta
authors: Harold I
authors: HI
authors: Feldman
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D016001:Confidence Intervals; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data*; D005260:Female; D006297:Health Services Accessibility; D006801:Humans; D007223:Infant; D008297:Male; D008329:Managed Care Programs; D008484:Medicaid; D008875:Middle Aged; D014481:United States