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    Chief Complaint


    Organ System


    Patent Pending

    4 A’s Test for Delirium Screening

    Diagnoses delirium in older patients.
    When to Use
    Why Use

    Patients admitted to geriatric wards, to screen for delirium.

    • Screens with higher sensitivity in patients without dementia.
    • No consensus exists for the assessment of inattention.
    • Limited external validation in some small populations, including the acute stroke setting.
    • Validated in non-English speaking patients with 91% sensitivity (De 2016).
    • Delirium is misdiagnosed, missed, or diagnosed late in over 60% of cases (Collins 2010). A simple screening tool can help identify these patients.
    • Can be used in patients deemed “untestable” by other tests.
    Mild sleepiness for <10 seconds after waking, then normal
    Clearly abnormal
    No mistakes
    1 mistake
    ≥2 mistakes or untestable
    Lists ≥7 months correctly
    Starts but lists <7 months, or refuses to start
    Untestable (cannot start because unwell, drowsy, inattentive)


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    Creator Insights
    Dr. Alasdair MacLullich

    About the Creator

    Alasdair MacLullich, BSc, MB ChB, MRCP(UK), PhD, FRCPE, is a professor of geriatric medicine at the University of Edinburgh in Scotland. He also leads the Edinburgh Delirium Research Group working to improve the understanding, detection and treatment of delirium. Dr. MacLullich's primary reseach is focused on the pathophysiology, neuropathology, and clinical assessment of delirium.

    To view Dr. Alasdair MacLullich's publications, visit PubMed

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    MDCalc loves calculator creators – researchers who, through intelligent and often complex methods, discover tools that describe scientific facts that can then be applied in practice. These are real scientific discoveries about the nature of the human body, which can be invaluable to physicians taking care of patients.
    About the Creator
    Dr. Alasdair MacLullich
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