Without evidence of benefit, an intervention should not be presumed to be beneficial or safe.

- Rogue Medic

Flawed Helicopter EMS vs Ground EMS Research – Part I

ResearchBlogging.org


Image source.

The media are posting headlines that there is finally evidence that helicopters save lives.[1]

This is from JAMA (Journal of the American Medical Association), which generated a bunch of headlines with the misleading claim that a glucose-insulin-potassium cocktail saves lives just a few weeks ago. The press bought it. A lot of people accepted the news reports.

Is this research similarly exaggerated far beyond what the evidence justifies?

Is this research valid?

Maryland already provided excellent evidence that MSPA (Maryland State Police Aviation unit – the only scene response EMS helicopters allowed in Maryland) were flying far too many patients. How did they demonstrate this? They cut the number of flights by well over half.

The head of Shock Trauma, Dr. Thomas Scalea seemed to be channeling one of the end of the world prophets when he said –

“Whenever someone says they want to ratchet it back,” says Dr. Thomas M. Scalea, physician in chief at Shock Trauma, “I tell them ‘OK, how many people can die next year to make that worthwhile?’”[2]

We are still waiting for Dr. Scalea to provide some sort of evidence that the fatality rate changed at all.

Where are the dead bodies that Dr. Scalea promised?

People constantly warn of death, destruction, and dogs and cats living together. I want results or an admission that the scare story was just that – a completely fabricated scare story, based entirely on the anxieties of the person speaking.

Has Dr. Scalea produced either?

This was a natural experiment. Where is the increased fatality rate?

Why did the authors of this study, from Shock Trauma in Maryland and Johns Hopkins in Maryland, have to find patients from other states to try to show a benefit from flying patients?

Are the authors admitting that flying patients in Maryland doesn’t improve outcomes?

Or are the authors admitting that they just can’t come up with any evidence that Maryland (the Helicopter EMS State) is providing any benefit to patients by putting so many of them in helicopters.

Few people doubt that there is a benefit from flying critically injured patients who are more than 45 minutes from the closest trauma center.

Did this show that there is any benefit to patient closer than 45 minutes from the closest trauma center?

No.

The authors didn’t draw any conclusions about time saved.

The authors used the NTDB® (National Trauma Data Bank®) to number crunch to find associations and they declared that association is proof. The NTDB® is very flawed data. I will explain in Part II.

Footnotes:

[1] Association between helicopter vs ground emergency medical services and survival for adults with major trauma.
Galvagno SM Jr, Haut ER, Zafar SN, Millin MG, Efron DT, Koenig GJ Jr, Baker SP, Bowman SM, Pronovost PJ, Haider AH.
JAMA. 2012 Apr 18;307(15):1602-10.
PMID: 22511688 [PubMed – indexed for MEDLINE]

Free Full Text from JAMA.

[2] Advantages of medevac transport challenged
Baltimore Sun
October 5, 2008
Article

Galvagno, S., Haut, E., Zafar, S., Millin, M., Efron, D., Koenig, G., Baker, S., Bowman, S., Pronovost, P., & Haider, A. (2012). Association Between Helicopter vs Ground Emergency Medical Services and Survival for Adults With Major Trauma JAMA: The Journal of the American Medical Association, 307 (15), 1602-1610 DOI: 10.1001/jama.2012.467

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Comments

  1. While we’re at it, let’s further justify the patients saved by going back to Korea and Vietnam and adding their medivac statistics.

    Oh, yeah, how many lives were lost in HEMS accross the board during this time? How many lives were lost (or careers ended due to injury) over non-critical transports or return trips home? How many aircraft were lost and at what expense?

    I’m sure by now you’ve seen http://tooldtowork.com/2012/04/surprise-surprise-surprise-3/

    • Christopher Matthews,

      One big problem with this study is that the authors do not demonstrate that flying patients saved any time.

      They ignored comparisons of time between ground EMS and helicopter EMS.

      I used to work in a trauma center that received a lot of patients by helicopter. We would still be waiting for the helicopter patients when the ambulances would have left after transporting patients from the same scene.

      Do helicopters save time?

      Only when used wisely by people trying to save time for the patient.

      There is nothing about this study to show that there was any difference in transport times.

      That did not stop the authors from claiming that the outcome they claim to have identified might be due to time saved. What if the prehospital times are prolonged by flying many of these patients? What is their conclusion in that case?

      .

  2. TOTWTYTR beat me to pointing out the irony of having a positive helicopter study take place in Baltimore.

    On the FFM podcast, you and Kyle discussed how medical helicopters are used to compensate for poor or inexperienced ground EMS. We, the EMS people, should make sure that the patients who benefit from a helicopter only benefit from speed, and that the treatment only available on helicopters now should be available from ground providers. That additional treatment should come with more understanding about which patients need to go directly to a trauma center as quickly as possible, which can be take a little longer to get there by ground, and which trauma patients can go to a community hospital. Designing a system that rotates medics between the ground and a helicopter would make this possible.

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