The double-edged sword of evidence-based medicine

EMS has gotten swept up in the evidence-based medicine craze in recent years. This is not at all a bad thing; on the contrary, it is probably the clearest path forward for a field that is continually locked in a struggle to carve out and maintain an identity within the healthcare community. There lurks danger, though, in becoming too dependent on only one mode of analysis and progressive impetus. This danger is primarily one of methodology and not of substance, but EMS leaders would nevertheless be wise to understand the limitations of evidence-based medicine. Like any other tool at the EMS provider's disposal, its capabilities must be exploited without losing sight of its shortcomings.

Years ago, a paramedic coworker loudly declared, "There has never been a single study that demonstrated any benefit to taking people to the hospital." This individual was particularly fond of loud declarations, but in this case he was spot on. It stands to reason that you should go to the hospital if you get sick or injured. but can you use statistics to demonstrate its superiority? That is, after all, the essence of evidence-based medical practice.

A popular anecdote among EMS providers is the 1998 study that tracked the outcomes of two groups of patients, one in New Mexico and one in Malaysia, who were transported after suffering spinal injuries. The patients in New Mexico were all placed in cervical collars and secured to backboards by EMS whereas the Malaysian group was not given the benefit of such "advanced" treatment. Guess which group had a lower incidence of permanent neurological deficits?

The spinal immobilization study is very much a success story for evidence-based medicine; selective spinal immobilization protocols have since been developed and promulgated widely. In my view, and that of more than a few training officers and medical directors, this is a huge step forward for EMS providers and the patients we treat. Score one for research.

But let's get back to the fact that we transport people to the hospital at all. There will never be a study that proves the benefit of transporting patients to the hospital because there will never be a study that even considers whether or not we should transport patients. Who would volunteer for the control group? "Well, Mrs. Smith, it appears you're suffering from acute pulmonary edema secondary to a CHF exacerbation. Unfortunately, you've been placed in the 'control group,' so we're not going to take you to the hospital today. Just keep gurgling away when you inhale and maybe some air will get in there. Have a nice day!" Common sense dictates that we transport patients to the hospital, and we will continue to do so--at least for high-acuity patients--as long as there is such a thing as EMS.

So does that mean that we should rely on reason and intuition to guide treatment protocols? Of course not. Just look at the evolution of cardiac arrest protocols: I've been in EMS for the better part of a decade now, and I've already seen several sea changes in the way cardiac arrests are managed (the changes in compression-to-ventilation ratios and the introduction of prehospital therapeutically-induced hypothermia leap to mind). There are providers out there with four times my level of experience who could describe countless more steps in the evolution of cardiac arrest management. The point is that as research sheds additional light on the pathophysiology of cardiac arrest, our treatment protocols are updated to match current understanding. And rinse and repeat. There is simply no other way to advance our understanding and treatment of that condition or many others.

How do we resolve the tension between letting research guide us forward while not getting paralyzed by the obsessive need to gather research to prove the unprovable? Fortunately the answer is simple: This is not a tension that needs resolving. Use research to gather as much information about as many pathologies and treatments as possible. Embrace whatever benefit can be gleaned from such study. But don't forget a liberal application of common sense to know what can and cannot be improved through scientific research. If we get too caught up in worshiping at the altar of evidence-based medicine, we lose sight of the fact that research is supposed to serve us, not the other way around.