Our primary objective was to determine the proportion of the population able to achieve acute cerebrovascular care in emergency stroke systems (ACCESS) in the United States. In addition, we examined how policy changes, including allowing ground ambulances to cross state lines and allowing air ambulances to transport patients from the prehospital setting to primary stroke centers (PSCs), would affect population access to stroke care.
Data were obtained via the US Census Bureau, The Joint Commission, and the Atlas and Database of Air Medical Services. Driving distances, ambulance driving speeds, and prehospital times were estimated using validated models and adjusted for population density. Access was determined by summing the population that could reach a PSC within the specified time intervals.
Main Outcome Measures
Thirty-, 45-, and 60-minute access by ground and air ambulance to PSCs.
Fewer than 1 in 4 Americans (22.3%) have access to a PSC within 30 minutes, less than half (43.2%) have access within 45 minutes, and just over half (55.4%) have access within 60 minutes. The use of air ambulances to deliver patients to PSCs would increase access from 22.3% to 26.0% for 30 minutes, 43.2% to 65.5% for 45 minutes, and from 55.4% to 79.3% for 60 minutes. The combination of prehospital regionalization and air ambulance transport of patients with acute stroke would reduce the 135.7 million Americans without 60-minute access to a PSC by half, to 62.9 million.
About half of the US population has timely access to a PSC. The use of air ambulances to triage patients with ischemic stroke to a PSC would increase the percentage of the US population with prompt access to stroke care. These data have implications for the ongoing design of the US stroke system.