Wednesday, November 7, 2012

Unsurprisingly, NHAMCS Data is Flawed

The National Hospital Ambulatory Medical Care Survey is a massive database of abstracted patient records, systematically generated to produce a representative sample of the nation's Emergency Department visits.

It should come as no surprise that retrospectively abstracted data from the electronic medical record sometimes fails to accurately reflect patient care.  The important question, however, is "how often?"  This review of NHAMCS by one of the Annals editors looked at a measurement that ought to be pretty obvious – intubation.  If you can't figure out whether a patient has been intubated via chart review, there's some serious issues with your data sourcing.  However, in this review of NHAMCS, the author interprets up to one in four charts as being potentially inaccurate due to inconsistencies between documented intubation and the final disposition of the patient (e.g., non-ICU settings, home, observation status, etc.)

Now, there are some instances in which patients are intubated in the Emergency Department – yet not subsequently dispositioned to a critical care or morgue – but these "temporary" intubations certainly do not constitute 25% of intubations.  The author goes on to note that Annals publishes a NHAMCS study at least twice a year – relatively influential towards practice given the Impact Factor – and the flaws in this data should limit the relative weighting of its importance.

"Congruence of Disposition After Emergency Department Intubation in the National Hospital Ambulatory Medical Care Survey"

1 comment:

  1. There is a similar problem with the National Trauma Data Bank®.

    Dr. Haut keeps using this to produce more studies, with a lot of media attention, but the data cannot be trusted.

    Of the trauma alerts entered in the NTDB®,

    49.3% had IVs started.

    8.1% had spinal immobilization.

    28.6% had MAST.

    8.1% had chest decompression.

    Does this reflect the experience of any trauma center?

    As many patients have chest decompression (attempted) as have spinal immobilization?

    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]
    http://www.ncbi.nlm.nih.gov/pubmed/21178760

    I agree that IV fluid does not improve outcome in trauma, but this study does nothing to prove that. His other NTDB® papers are just as bad at drawing unwarranted conclusions and unreasonably hyping them.

    For example -

    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]
    http://www.ncbi.nlm.nih.gov/pubmed/22511688

    Spine immobilization in penetrating trauma: more harm than good?
    Haut ER, Kalish BT, Efron DT, Haider AH, Stevens KA, Kieninger AN, Cornwell EE 3rd, Chang DC.
    J Trauma. 2010 Jan;68(1):115-20; discussion 120-1.
    PMID: 20065766 [PubMed - in process]

    .

    ReplyDelete

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