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 II

ResearchBlogging.org

Continuing from Part I of the latest JAMA headline grab based on exaggerations of what the research almost shows.

What about the times?

Total elapsed EMS times from dispatch to ED arrival were excluded as a variable be cause of a 57.8% prevalence of missing data (eFigure). A sensitivity analysis was performed for all complete cases to examine the role of total EMS times as an independent variable.[1]

Most of the data was incomplete? Is this a surprise?

No. The authors used the NTDB® (National Trauma Data Bank®) to number crunch to find associations and then declared that association is proof. The NTDB® is very flawed data.

The scientific method does not state that we should use weak data to data mine for associations and then claim that these weak associations are proof of anything. This is a failure to use the scientific method.

The NTDB® has been used before. I have pointed out the flaws with the NTDB® before.

The NTDB® is just incomplete and misleading data.


Click on images to make them larger.[2] [3]

Do any of these numbers come anywhere close to representing the trauma patients you deal with?

More than three patients have MAST applied for every spinal immobilization?

Half of trauma patients have an IV started, but only 8.1% are immobilized?

For every spinal immobilization, there is a needle decompression of the chest?

For every time you did one of these –


Image credit.

You did one of these –


Image credit.

If you immobilized 100 patients this year. If you represent the average, you also needle decompressed about 100 patients. This is what we are supposed to believe if we are going to accept the NTDB® data. Maybe I am wrong. Maybe this association represents reality and I just don’t get it.

I hope you used better needle decompression technique, even though we are dealing with a purely imaginary association and an image from fiction.

This is an example of the quality of the NTDB® data and the fantastic associations we can find in fairy tales.

But wait – there’s more.

Should you trust just me?

While it may be impossible to prove conclusively our hypothesis that co-morbidities and complications are underreported in the NTDB, our study certainly raises the strong possibility that this could be the case. Rates of complications within the NTDB are astonishingly low especially when compared to the UM NSQIP General Surgery group which represents a reference cohort of largely elective operative cases.[4]

There aren’t just problems with the prehospital data. The problems appear to be throughout the NTDB® data.

We do not learn anything about the effect of helicopters on outcomes by mining the NTDB® data.

Next the authors will tell us they have used the NTDB® data to answer the ancient question of How many angels can dance on the head of a pin?

Act now. Order your copy of the NTDB® psychic predictions kit today. If you are among the first 73 callers, you get a free pair of hip waders, which are essential for dealing with data of this quality.


Image credit.

You will have to provide your own shovel.

See also –

510 Medic – Helicopter EMS is Associated with Improved Survival…But is that Enough?

The Trauma Professional’s Blog – Trauma Survival and Air vs Ground Transport

Too Old To Work, Too Young To Retire – Surprise, Surprise, Surprise

A Day in the Life of an Ambulance Driver – Does Helicopter EMS Provide Any Benefit Compared to Ground?

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] Prehospital Intravenous Fluid Administration is Associated With Higher Mortality in Trauma Patients: A National Trauma Data Bank Analysis.
Haut ER, Kalish BT, Cotton BA, Efron DT, Haider AH, Stevens KA, Kieninger AN, Cornwell EE 3rd, Chang DC.
Ann Surg. 2010 Dec 20. [Epub ahead of print]
PMID: 21178760 [PubMed – as supplied by publisher]

Full Text in PDF format from www.medicalscg.

[3] Prehospital Intravenous Fluid Administration is Associated With Higher Mortality in Trauma Patients – Part III
Tue, 01 Mar 2011
Rogue Medic
Article

[4] Detecting the blind spot: complications in the trauma registry and trauma quality improvement.
Hemmila MR, Jakubus JL, Wahl WL, Arbabi S, Henderson WG, Khuri SF, Taheri PA, Campbell DA Jr.
Surgery. 2007 Oct;142(4):439-48; discussion 448-9.
PMID: 17950334 [PubMed – indexed for MEDLINE]

Free Full Text from PubMed Central

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

Haut ER, Kalish BT, Cotton BA, Efron DT, Haider AH, Stevens KA, Kieninger AN, Cornwell EE 3rd, & Chang DC (2010). Prehospital Intravenous Fluid Administration is Associated With Higher Mortality in Trauma Patients: A National Trauma Data Bank Analysis. Annals of surgery PMID: 21178760

Hemmila, M., Jakubus, J., Wahl, W., Arbabi, S., Henderson, W., Khuri, S., Taheri, P., & Campbell, D. (2007). Detecting the blind spot: Complications in the trauma registry and trauma quality improvement Surgery, 142 (4), 439-449 DOI: 10.1016/j.surg.2007.07.002

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Comments

  1. Thanks for breaking the data down like that. I read the information, but decided to wait on your analysis to make any sense of it.

    That’s my favorite scene from that movie, also.

    • CCC,

      Thanks for breaking the data down like that. I read the information, but decided to wait on your analysis to make any sense of it.

      There is no sense to make of it. The sad thing is that Dr. Peter Pronovost is associated with this. He should know better.

      That’s my favorite scene from that movie, also.

      What?

      What?

      What?

      🙂

      .

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