Trauma patients with life-threatening injuries have a better chance of surviving if they are taken to the hospital by helicopter rather than ambulance, a study found.

Seriously injured patients are 16 percent more likely to survive and be discharged from the hospital if the helicopter is used for emergency transportation, research today in the Journal of the American Medical Association showed. It’s unclear why the flights save more lives, though speed doesn’t seem to be the answer because the transport time was similar in many cases, said Adil Haider, the study author.

“What we really need to do is figure out who are those severely injured patients who could benefit,” said Haider, an associate professor of surgery, anesthesiology and critical care medicine at the Johns Hopkins University School of Medicine in Baltimore, in an April 13 telephone interview. “We just need to make sure that the helicopters are getting to the people who need it the most. These helicopters are saving lives.”

More than 50 million people are injured in the U.S. each year and more than 169,000 die of their injuries, the authors wrote. Helicopter flights cost from $5,000 to $10,000, while the expense of an ambulance trip is $500 to $1,500, Haider said.

The data showed about $350,000 would have to be spent in helicopter transportation to save one life, about the same cost as needed to save one patient using open-heart surgery, he said.

National Data Bank

In the study, the researchers looked at the records of more than 223,475 patients ages 16 and older who were in the National Trauma Data Bank. Those in the study had at least moderately severe injuries and were taken to trauma hospitals. Of those, 61,909 were transported by helicopter and 161,566 were transported by ambulance.

Researchers found that 7,813 patients transported by helicopter died compared with 17,775 of those taken by ground services.

While the study showed helicopters didn’t travel any faster than ambulances in many cases, they may carry the most-advanced equipment and their patients may receive more intensive treatment once they land, Haider said.

“This study does a very good job of reinforcing what some of the other recent studies have shown, that helicopters do make a difference in severely injured patients,” said Mark Gestring, medical director of the Kessler Trauma Center at the University of Rochester Medical Center in Rochester, New York, who wasn’t an author of today’s study.

“It sets the stage for the next question, how do you decide which injured patients fly and which don’t need to,” said Gestring, who wrote a paper last year looking at the benefits of helicopter transportation.