Air ambulance vendors have prevailed in workers’ compensation litigation allowing them to be exempt from state adopted maximum fee schedules. Courts have found that federal law regulating air carriers preempts state law. The cost of an air ambulance transport is therefore uncontrolled, and unfettered. However, their may remain legal challenges to these fees based upon medical necessity.

Researchers at the Stanford University School of Medicine have for the first time determined how often emergency medical helicopters need to help save the lives of seriously injured people to be considered cost-effective compared with ground ambulances. The researchers found that if an additional 1.6 percent of seriously injured patients survive after being transported by helicopter from the scene of injury to a level-1 or level-2 trauma center, then such transport should be considered cost-effective. In other words, if 90 percent of seriously injured trauma victims survive with the help of ground transport, 91.6 need to survive with the help of helicopter transport for it to be considered cost-effective. The study, published online in the Annals of Emergency Medicine, does not address whether most helicopter transport actually meets the additional 1.6 percent survivorship threshold.

The study summarized in an article in Science Daily, comes at a time when finding ways to cut medical costs has become a national priority, and the overuse of helicopter transport has come under scrutiny. Previous studies have shown that, on average, over half of patients transported by helicopter have only minor, non-life threatening injuries. For these patients, transport by helicopter instead of ground ambulance is not likely to make a difference in outcomes, and the additional risk and cost of helicopter transport outweighs the benefit, the study’s lead author, M. Kit Delgado, MD, MS,said.

In 2010, there were an estimated 44,700 U.S. helicopter transports from injury scenes to level-1 and level-2 trauma centers, with an average cost of about $6,500 per transport. The total annual cost is around $290 million. (Level-1 and -2 trauma centers are hospitals equipped and staffed to provide the highest levels of surgical care to trauma patients; level-1 centers offer a broader array of readily available specialty care, and also are committed to research and teaching efforts.)

Yet emergency helicopter transport sits in a cost-efficiency conundrum: It is most needed in remote, rural areas where transport by ground can take far longer than by air. These areas also tend to have sparser populations and therefore fewer calls for aid, making it difficult to recoup the overhead costs of maintaining helicopter services, Delgado said. In some areas of the country, however, helicopters are automatically launched based on the 911 call. “Once ground responders and the helicopter arrive, sometimes they may find patients who are awake, talking and have stable vital signs,” Delgado said. “The challenge is getting helicopters to patients who need them in a rapid fashion so the flight team can intervene and make a difference, but also know based on certain criteria who isn’t sick enough to require air transport.”

There is mixed evidence in the literature about the degree to which helicopter transport reduces mortality. It is therefore uncertain whether the routine use of helicopter transport is cost-effective for most patients in the United States when ground transport is also feasible. The study found that the cost-effectiveness also depends on regional variation in the costs of air and ground transport and the percentage of patients who are flown that have minor injuries.