May 3, 2012
According to researchers from the Johns Hopkins School of Medicine, injuries sustained in trauma remain the leading cause of death or disability among young people worldwide. In fact, more than 50 million people per year are injured in the United States and approximately 169,000 of them die from trauma.
Looking for a way to reduce these numbers, a Hopkins research team has looked at transport by helicopter versus ambulance for trauma patients. "There has never been any real, randomized control trial to determine which is better," Adil Haider, senior author of the study and Associate Professor of Surgery, Anesthesiology and Critical Care Medicine said.
He and his colleagues found that patients who are transported by helicopter are 16 percent more likely to survive.
Although the study did not look at the specific causes of why helicopter transport can be more effective, the researchers hypothesized that patients utilizing this transport method reach the hospital more quickly, and that helicopters tend to have more experienced emergency medical teams than ambulances do, possibly providing a better quality of care.
The study looked at 223,475 patients older than 15 who had sustained blunt or penetrating trauma between the years 2007 and 2009 who needed to be transported to Level I or II trauma centers. A Level I trauma center is highest ranked and in general provides the best level of care. A Level II trauma center has the second-highest ranking and also provides comprehensive care.
The researchers obtained patients' records from the American College of Surgeons National Trauma Data Bank. They considered a patient to have survived if he or she was eventually discharged from the hospital.
More than 161,500 patients studied were taken to hospitals by ambulances, while approximately 62,000 were transported by helicopters. 17,775 patients taken by ground transportation died, compared with 7,813 patients transported by helicopter.
The researchers had to account for many variables among the different patients, including age, sex, ethnicity, type of trauma and the trauma center to which the patient was transported.
"The study did encounter some technical difficulties because of the very large sample size and the significant concern of selection bias," Haider said.
The researchers evaluated the data in three ways: logistic regression, logistic regression with clustering, and propensity score-matching.
If trauma patients are more likely to survive when transported by helicopter, then why aren't helicopters used more often? The answer lies in cost. Helicopter transportation is one of the highest pre-hospital costs in treating trauma patients. The annual cost of helicopter transportation ranges at different hospitals from $114,777 to $4.5 million.
The study found that on average, one in every 65 trauma patients transported by ambulance to a Level I trauma center dies. Using the fact that the cost of helicopter transportation in Maryland is approximately $5,000, the researchers estimate that $325,000 would have to be used to save one life.
However, Md. has the only state-run helicopter system in the United States, which means that the cost to transport someone by helicopter here is much lower than average. In most states, using a helicopter is charged to insurance companies and patients.
Since transporting all patients by helicopter is not a feasible option, the researchers have suggested using better guidelines to determine when to call one in.
"First responders have to make a tough call," Haider said. "It is difficult to figure out with precision what is going on with a patient."
Haider believes that more research is needed to find out when helicopters can best be utilized. The study was published in the April 18 issue of the Journal of the American Medical Association.