Researchers at the Stanford University School of Medicine in the US have announced that they 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 report that if an additional 1.6 per cent of seriously injured patients survive after being transported by helicopter from the scene of injury to a level-1 or level-2 trauma centre, then such transport should be considered cost-effective – for example, if 90 per cent 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 per cent survivorship threshold. “What we aimed to do is reduce the uncertainty about the factors that drive the cost-effective use of this important critical care resource,” explained lead author Dr M. Kit Delgado, an instructor in the Division of Emergency Medicine. “The goal is to continue to save the lives of those who need air transport, but spare flight personnel the additional risks of flying – and patients with minor injuries the additional cost – when helicopter transport is not likely to be cost-effective.”
The University reflected that the study 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, adding that 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, Delgado said.
According to the study, in 2010, there were an estimated 44,700 US helicopter transports from injury scenes to level-1 and level-2 trauma centres, with an average cost of around $6,500 per transport, giving a total annual cost of around $290 million. Yet, say the authors, emergency helicopter transport ‘sits in a cost-efficiency conundrum’. Delgado stated: “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.” He added: “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.”
Most health economists consider medical interventions that yield a year of healthy life – a measure known as a quality-adjusted life-year (QALY) – at a cost of between $50,000 and $100,000 to be cost-effective in high-income countries such as the US, Delgado said. If society is willing to pay as much as $100,000 toward helicopter transport for each QALY gained by the seriously injured patients, then helicopter transport needs to reduce the mortality rate of these patients by a modest 1.6 per cent compared with ground transport to meet this threshold, the study says – or it needs to improve long-term disability outcomes. Delgado continued: “If future studies find helicopter transport leads to improved long-term quality of life and disability outcomes, then helicopter transport would be considered cost-effective, even if no additional lives were saved. Only a handful of studies have examined outcomes other than death, without definitive results.”
In addition, the study found that the cost-effectiveness depends on regional variation in the costs of air and ground transport and the percentage of patients who are flown that have minor injuries.
The senior author of the study was Dr Jeremy Goldhaber-Fiebert, assistant professor of healthcare research and policy. Other Stanford co-authors were Dr Kristan Staudenmayer, assistant professor of surgery; Dr N. Ewen Wang, associate professor of emergency medicine; Dr David Spain, professor of surgery; and Dr Douglas Owens, professor health research and policy. The study was supported by the Agency for Healthcare Research and Quality, the National Institutes of Health and the Department of Veterans Affairs.