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HEMS Coverage of Population / Motor Vehicle Crash Sites

Optimal response and triage of car crash victims has been shown to improve injury outcomes and Helicopter Emergency Medical Services (HEMS) play a key role in this response [1,2]. 

A study was recently performed by the CenTIR to assess whether fatal crash site density patterns follow population density patterns in the continental U.S.  In addition, the study used multi-year ADAMS base data to examine how HEMS coverage of populations and fatal motor vehicle crash (MVC) sites (from FARS) has changed between 2004 and 2007 [3].   To illustrate how coverage was assessed, the adjacent map shows fatal motor vehicle crash sites and HEMS base locations, the latter with a 10 minute fly circle (or nominal 20 minute response radius).  These fly circles were used as a metric to quantify coverage of the MVC sites.  (Ground transport candidates, defined as  MVC sites within 8 mile radius or nominal 10 mile drive of a trauma center, were excluded when estimating crash site coverage for air medical response.)  

The study demonstrated that fatal motor vehicle crash density patterns differ from population density patterns.  Thus, for trauma response, consideration of historical motor vehicle crash locations provides a valuable alternative to population locations when assessing HEMS base placement and coverage patterns. The study further showed that coverage of both populations and fatal crash sites has increased significantly between 2004 and 2007.  Regardless, there are still rural areas with significant numbers of fatal crashes but little or no timely access to air medical services.

[1]. MacKenzie, EJ.; Rivara, FP.; Jurkovich, GJ.; Nathens, A.; et al. A National Evaluation of the Effect of Trauma-Center Care on Mortality. N Engl J Med 2006;354: 366-78
[2]. Thomas , SH.; Helicopter EMS Transport Outcomes Literature: Annotated Review of Articles Published 2004-2006, Prehospital Emergency Care,Vol 11;4; October 2007: 477-488
[3]. Marie Flanigan, Alan Blatt, Kevin Majka (CUBRC), Louis Lombardo (NHTSA, retired).  “HEMS Coverage of Populations & Rural Motor Vehicle Crash Site in the U.S.”, AIRMED 2008 World Congress, Prague, Czech Republic, May 20-23, 2008 and Proceedings of the Scientific Assembly of the Air Medical Transport Conference, Minneapolis, MN.  Air Medical Journal, Vol 27, Issue 5, September, 2008.