Increased mortality in rural vehicular trauma: identifying contributing factors through data linkage

Fatality rates from rural vehicular trauma are almost double those found in urban settings. Causes of this difference in rural and urban trauma fatality rates have yet to be fully explored. The purpose of this study is to identify prehospital causes of the higher rural fatality rates by linking, analyzing, and comparing prehospital data for rural and urban vehicular crashes.

A probabilistic algorithm was developed that permitted linkage of data from police motor vehicle crash reports, and from Emergency Medical Service (EMS), and hospital records. Motor vehicle crashes (MVCs) were defined as rural or urban by location of the crash using the United States Bureau of Census criteria. Areas that fell outside that urban definition were defined as rural. Linked data were analyzed to identify factors that were thought to be associated with the higher mortality rates observed in rural settings.

During the 20-month period from November 2001 through May 2003, data were collected from police crash reports and EMS Patient Care Reports (PCRs) within seven counties in southwest Alabama. Using high probability match criteria and join specifications, 4,694 police crash reports were linked to EMS PCRs. Of these, 3,068 patients (65.4%) were injured in rural settings, and 1,626 (34.6%) were injured in urban settings. A total of 164 (3.5%) mortalities were identified. A total of 129 (4.2%) mortalities occurred in a rural setting and 35 (2.1%) were urban (p = 0.0001). Of the 129 rural deaths, 91 (70.5%) were dead on scene (DOS) and of 35 urban deaths, 20 (57.1%) were DOS (p < 0.0001). Mean EMS response time for rural MVCs with survivors was 11.2 minutes versus a mean of 13.9 minutes for rural MVC with survivors (p < 0.0002). When survivors were involved, mean EMS response time for an urban setting was 6.8 minutes versus 13.9 minutes for a rural setting (p < 0.0001). In a rural setting, mean EMS distance to the scene when patients were alive was 7.7 miles versus 10.5 miles when patients were DOS (p < 0.001). For patients who died after transfer from the scene, mean rural EMS time on scene was 16.1 minute versus 11.6 minutes in an urban setting (p < 0.04).

In a setting of rural MVC, increased EMS response time, time on scene and distance to the scene are associated with higher rural trauma mortality rates.