In 2009, Secretary of Defense Robert M. Gates mandated the "golden hour policy," which required helicopter transport of critically-injured combat soldiers in 60 minutes or less. Prior to this mandate, the military time goal was twice that — two hours from call to hospital arrival. A new study of the Afghanistan conflict finds the 2009 mandate resulted in a reduction in transport time and, more importantly, improved survival rates for combat casualties.

“Despite evidence of increased severity and complexity of wounds from explosive devices, the combination of reduced prehospital transport time and increased treatment capability are likely contributors of casualty survival,” concluded the authors.

Lead author Dr. Russ S. Kotwal, United States Army Institute of Surgical Research, explained how the military has provided various standards, directives, and guidelines to first responders and this "has improved the probability that casualties will arrive at the hospital alive so they can benefit from the trauma care system now in place."

"However, not all opportunities have been realized," Kotwal told Medical Daily. "The remaining challenge is to refine performance improvements and best practices through system-wide prehospital data collection. Additionally, these prehospital practices and data collection efforts needs to be mandated and standardized throughout the Department of Defense."

Trauma: A History

Dr. R. Adams Cowley, referred to as “the father of trauma medicine,” is credited with coining the term “golden hour” to promote urgency between injury and care. Minimizing the time between critical injury and hospital arrival is important in any trauma system, yet nowhere is it more crucial than on a battlefield. So, over the years, military doctors have whittled down prehospital transport time dramatically: from 10 hours in World War II to five hours in the Korean conflict to just one hour in Vietnam, according to Kotwal and his co-authors. The greatest debt is owed to technology in the form of helicopters, first used in Korea, and since extended to civilian trauma programs, including more than 250 in the United States and 1,000 worldwide.

It seems natural to assume the mandate of a golden hour policy would automatically improve the military’s trauma response… but did it?

Kotwal and his colleagues investigated. Their analysis focused on the Afghanistan conflict from September 2001 to March 2014 and included battlefield data for 21,089 U.S. military casualties. The research team first compared morbidity and mortality results for casualties before and after the mandate. Then, the team examined results for those who underwent prehospital helicopter transport in 60 minutes or less versus more than 60 minutes.

Following adoption of the golden hour policy, the researchers observed a decline in the percentage killed in action (from 16 percent to 9.9 percent), while also seeing a decrease in the case fatality rate (from 13.7 percent to 7.6 percent). The plunging case fatality rate was associated with an increasing percentage of casualties transported in 60 minutes or less, the researchers say. However, one important number remained stubbornly unchanged: The percentage of those who died of their wounds hovered just above 4 percent both before and after policy adoption.

For a subset of casualties, a total of 4,542 service members, the researchers had access to more detailed data. Here, they saw a decrease in median transport time following the mandate, while the number of missions achieving transport time in 60 minutes or less increased substantially, from 25 percent to 75 percent.

“The data show that compliance with the 2009 mandate resulted in shorter transport times and enhancements to treatment capability that improved outcomes and potentially saved 359 lives,” wrote the authors. In a linked commentary, Dr. Todd E. Rasmussen, U.S. Combat Casualty Care Research Program, stressed "the effectiveness of combining advanced trauma care capability with informed policy," while further arguing, "the study demonstrates one without the other — capability without policy or policy without capability — results in compromised success."

Source: Kotwal RS, Howard JT, Orman JA, et al. The Effect of a Golden Hour Policy on the Morbidity and Mortality of Combat Casualties. JAMA Surgery. 2015.

Note: Direct quotes from Dr. Kotwal were added to this article shortly after publication.