Expansion of U.S. emergency medical service routing for stroke care: 2000-2010

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.

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.

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.

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.