A meta-analysis of prehospital care times for trauma.

Background: Time to definitive care is a major determinant of trauma patient outcomes yet little is empirically known about prehospital times at the national level. We sought to determine national averages for prehospital times based on a systematic review of published literature.

Methods: We performed a systematic literature search for all articles reporting prehospital times for trauma patients transported by helicopter and ground ambulance over a 30-year period. Forty-nine articles were included in a final meta-analysis. Activation time, response time, on-scene time, and transport time were abstracted from these articles. Prehospital times were also divided into urban, suburban, rural, and air transports. Statistical tests were computed using weighted arithmetic means and standard deviations.

Results: The data were drawn from 20 states in all four U.S. Census Regions and represent the prehospital experience of 155,179 patients. Average duration in minutes for urban, suburban, and rural ground ambulances for the total prehospital interval were 30.96, 30.97, and 43.17; for the response interval were 5.25, 5.21, and 7.72; for the on-scene interval were 13.40, 13.39, and 14.59; and for the transport interval were 10.77, 10.86, and 17.28. Average helicopter ambulance times were response 23.25, on-scene 20.43, and transport 29.80 minutes.

Conclusions: Despite the emphasis on time in the prehospital and trauma literature there has been no national effort to empirically define average prehospital time intervals for trauma patients. We provide points of reference for prehospital intervals so that policymakers can compare individual emergency medical systems to national norms.