A study recently published in JAMA has been making the rounds in the EMS forums and blogosphere, purporting to prove that a certain subset of trauma patients transported by helicopter has a higher survival rate than comparable patients transported by ground EMS.
First I'd like to point out that, whenever you read a study, it's also wise to consider the potential biases of the researchers. I'm not suggesting that the authors here would be so unethical as to fake their numbers to arrive at a predetermined conclusion – far from it. I do believe, however, that it is human to interpret the findings in such a way that they support what we think is right.
A Fort Detrick medic in a CCEMT-P class in Piuttsburgh told me years ago, "How do you confuse a Maryland EMT? Ask him to drive to the Trauma Center."
If you had to pick any single state that is most heavily invested in helicopter EMS, that state would be Maryland, and that is true even after reining things in a bit after the crash of Maryland State Police Trooper Two on a medevac flight in 2008.
I'll state my position here, lest someone accuse me (yet again) of having an axe to grind against helicopter EMS:
I believe helicopter EMS is useful. I believe it saves lives. I also believe that it is vastly overused, inherently dangerous, and that the overhwelming majority of the people we fly don't need a helicopter. I believe that a significant chunk of them don't even need a trauma center. And I believe that we owe it to the HEMS crewmembers who make those flights, not to endanger them needlessly by sending them out for silly shit.
I keep waiting for the study that definitively identifies the subset of trauma (or medical) patients that benefits from helicopter transport. When we have it, we can revise our transport criteria accordingly, rather than our current critera of worshipping the Cult of Mechanism.
I don't think this is that study.
Rogue Medic does a good job of fisking this study on his blog. I urge you to read both parts:
Pay particular attention to the inaccuracy and incompleteness of the National Trauma Data Bank that he highlights in Part II, and ask yourself if we should believe a helicopter EMS study that uses those numbers.
Heck, ask yourself if we should believe any study that uses those numbers.