title: Expansion of U.S. emergency medical service routing for stroke care: 2000-2010.
abstract: BACKGROUND
  Organized stroke systems of care include preferential emergency medical services (EMS) routing to deliver suspected stroke patients to designated hospitals. To characterize the growth and implementation of EMS routing of stroke nationwide, we describe the proportion of stroke hospitalizations in the United States (U.S.) occurring within regions having adopted these protocols.
  
  
  METHODS
  We collected data on ischemic stroke using International Classification of Diseases-9 (ICD-9) coding from the Healthcare Cost and Utilization Project Nationwide Inpatient Sample (NIS) database from the years 2000-2010. The NIS contains all discharge data from 1,051 hospitals located in 45 states, approximating a 20% stratified sample. We obtained data on EMS systems of care from a review of archives, reports, and interviews with state emergency medical services (EMS) officials. A county or state was considered to be in transition if the protocol was adopted in the calendar year, with establishment in the year following transition.
  
  
  RESULTS
  Nationwide, stroke hospitalizations remained constant over the course of the study period: 583,000 in 2000 and 573,000 in 2010. From 2000-2003 there were no states or counties participating in the NIS with EMS systems of care. The proportion of U.S. stroke hospitalizations occurring in jurisdictions with established EMS regional systems of acute stroke care increased steadily from 2004 to 2010 (1%, 13%, 28%, 30%, 30%, 34%, 49%). In 2010, 278,538 stroke hospitalizations, 49% of all U.S. stroke hospitalizations, occurred in areas with established EMS routing, with an additional 18,979 (3%) patients in regions undergoing a transition to EMS routing.
  
  
  CONCLUSIONS
  In 2010, a majority of stroke patients in the U.S. were hospitalized in states with established or transitioning to organized stroke systems of care. This milestone coverage of half the U.S. population is a major advance in systematic stroke care and emphasizes the need for novel approaches to further extend access to stroke center care to all patients.
authors.affiliation: University of Southern California Keck School of Medicine, Department of Biostatistics, Los Angeles, California.
authors.forename: Natalie
authors.initials: N
authors.lastname: Hanks
authors.affiliation: University of Southern California Keck School of Medicine, Department of Biostatistics, Los Angeles, California.
authors.forename: Ge
authors.initials: G
authors.lastname: Wen
authors.affiliation: University of Southern California Keck School of Medicine, Los Angeles, California.
authors.forename: Shuhan
authors.initials: S
authors.lastname: He
authors.affiliation: Rush University School of Medicine, Department of Neurology, Chicago, Illinois.
authors.forename: Sarah
authors.initials: S
authors.lastname: Song
authors.affiliation: University of California Los Angeles, Department of Neurology and Stroke Center, Los Angeles, California.
authors.forename: Jeffrey L
authors.initials: JL
authors.lastname: Saver
authors.affiliation: University of Southern California Keck School of Medicine, Departments of Neurology and Roxanna Todd Hodges Comprehensive Stroke Clinic, Los Angeles, California.
authors.forename: Steven
authors.initials: S
authors.lastname: Cen
authors.affiliation: University of Southern California Keck School of Medicine, Departments of Neurology and Roxanna Todd Hodges Comprehensive Stroke Clinic, Los Angeles, California.
authors.forename: May
authors.initials: M
authors.lastname: Kim-Tenser
authors.affiliation: University of Southern California Keck School of Medicine, Departments of Neurosurgery and Roxanna Todd Hodges Comprehensive Stroke Clinic, Los Angeles, California.
authors.forename: William
authors.initials: W
authors.lastname: Mack
authors.affiliation: University of Southern California Keck School of Medicine, Departments of Neurology and Roxanna Todd Hodges Comprehensive Stroke Clinic, Los Angeles, California.
authors.forename: Nerses
authors.initials: N
authors.lastname: Sanossian
mesh_terms: D004632:Emergency Medical Services / Q000458:organization & administration*; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D020521:Stroke / Q000453:epidemiology / Q000628:therapy*; D013781:Texas / Q000453:epidemiology; D014481:United States / Q000453:epidemiology