Transport by helicopter to a level I or II trauma center was associated with improved survival to hospital discharge compared with ground emergency medical services, according to a study that included data on more than 200,000 adult patients.
In background information for the article, which appears in the April 18 issue of JAMA, researchers noted that trauma remains the leading cause of death and disability among young people around the world. In the United States, more than 50 million people per year suffer traumatic injuries, resulting in 169,000 deaths a year and a lifetime cost of $406 billion.
The use of helicopter EMS and its possible effect on outcomes for traumatically injured patients has been the subject of debate, the authors noted. Adil H. Haider, MD, MPH, FACS, of the Johns Hopkins University School of Medicine in Baltimore, and colleagues conducted a study to compare the association between the use of helicopter vs. ground EMS and survival among adults with traumatic injuries.
The study included 223,475 patients older than 15 who had an injury severity score that was defined as major trauma, having sustained blunt or penetrating trauma that required transport to U.S level I or II trauma centers. Of the study population, 61,909 patients were transported by helicopter and 161,566 by ground to trauma centers.
Unadjusted mortality was higher for those transported by helicopter (12.6%) than those by ground (11%); however, a higher proportion of both level I and level II patients transported by helicopter had higher injury severity scores. After further analyses and controlling for multiple known confounders, helicopter transport was associated with a 16% improved odds of survival compared with ground transport for patients transported to level I trauma centers (absolute risk reduction of 1.5%). For patients transported to level II trauma centers, helicopter transport was associated with a 15% improved odds of survival (absolute risk reduction of 1.4%).
“Thus, for patients transported to level I trauma centers by helicopter, 65 patients would need to be transported to save one life,” the authors wrote. “For patients transported to level II trauma centers, the number needed to treat is 69.”
Which aspect of helicopter transport is responsible for the mortality benefit in this highly stratified sample is unclear, the authors said. “Future studies should investigate specific components of helicopter EMS such as prehospital interventions, total prehospital time, crew configuration and distance as factors that may in part or whole explain the benefit of helicopter EMS for adults with major trauma because understanding the effectiveness of each may help determine which patients benefit most from this resource.”
The development and use of effective prehospital triage tools that can identify adults with a high injury severity score have remained elusive, the researchers said. “Future studies should focus on efficient and user-friendly prehospital assessment tools to properly identify injured adults who will be the most likely to benefit from helicopter transport.”
Haider presented the findings April 17 at the National Press Club in Washington, D.C., as part of a JAMA media briefing on comparative effectiveness research. To view the study data and access the study via subscription or purchase, visit http://bit.ly/HRa1K6.