National characteristics of emergency medical services responses in the United States.

OBJECTIVE: Despite its long history and current prominence in U.S. communities, only limited data describe the national characteristics of emergency medical services (EMS) care in the United States. We sought to characterize out-of-hospital EMS care in the United States.
METHODS: We conducted an analysis of the 2010 National Emergency Medical Services Information System (NEMSIS) research data set, encompassing EMS emergency response data from 29 states. From these data, we estimated the national number and incidence of EMS responses. We also characterized EMS responses and the patients receiving care.
RESULTS: There were 7,563,843 submitted EMS responses, corresponding to an estimated national incidence of 17.4 million EMS emergency responses per year (56 per 1,000 person-years). The EMS response incidence varied by U.S. Census region (South 137.4 per 1,000 population per year, Northeast 85.2, West 39.7, and Midwest 33.3). The use of lights and sirens varied across Census regions (Northeast 90.3%, South 76.7%, West 68.8%, and Midwest 67.5%). The percentage of responses resulting in patient contact varied across Census regions (range 78.4% to 95.7%). The EMS time intervals were similar between Census regions; response median 5 minutes (interquartile range [IQR] 3-9), scene 14 minutes (10-20), and transport 11 minutes (7-19). Underserved populations (the elderly, minorities, rural residents, and the uninsured) were large users of EMS resources.
CONCLUSION: These data highlight the breadth and diversity of EMS demand and care in the United States.