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Try the 4AT

The full 4AT with automatic scoring. No patient data is stored or transmitted.

4AT interactive calculator

The 4AT is scored from 0-12

  • 0 suggests no delirium and no moderate-severe cognitive impairment
  • 1-3 suggests cognitive impairment but not delirium
  • 4 or more suggests delirium

Select one score for each item. No patient information is stored or transmitted.

[1] Alertness

This includes patients who may be markedly drowsy (eg. difficult to rouse and/or obviously sleepy during assessment) or agitated/hyperactive. Observe the patient. If asleep, attempt to wake with speech or gentle touch on shoulder. Ask the patient to state their name and address to assist rating.

[2] AMT4

Age, date of birth, place (name of the hospital or building), current year.

[3] Attention

Ask the patient: "Please tell me the months of the year in backwards order, starting at December." To assist initial understanding one prompt of "what is the month before December?" is permitted.

[4] Acute change or fluctuating course

Evidence of significant change or fluctuation in: alertness, cognition, other mental function (eg. paranoia, hallucinations) arising over the last 2 weeks and still evident in last 24hrs

[1] Alertness scoring explanation
  • Score 0: Patient is fully alert (but not agitated) throughout assessment OR briefly sleepy for <10 seconds after waking, then normal
  • Score 4: Patient exhibits any of these:
    • Clearly abnormally drowsy
    • Agitated/hyperactive
    • Not fully alert throughout assessment
[2] AMT4 scoring explanation

Tests patient's ability to correctly state:

  • Age
  • Date of birth
  • Place (name of hospital/building)
  • Current year
  • Score 0: No mistakes
  • Score 1: One mistake
  • Score 2: Two or more mistakes, or untestable
[3] Attention scoring explanation

Patient is asked to list months in reverse order, starting from December.

  • Score 0: Recites 7 months or more correctly
  • Score 1: Starts but scores <7 months, or refuses to start
  • Score 2: Untestable (cannot start because unwell, drowsy, inattentive)
[4] Acute Change or Fluctuating Course scoring explanation

Evidence of significant change or fluctuation in:

  • Alertness
  • Cognition
  • Other mental function (e.g. paranoia, hallucinations)

Changes must have:

  • Arisen over the last 2 weeks
  • Still be evident in last 24hrs
  • Score 0: No evidence of acute change or fluctuation
  • Score 4: Evidence of significant change or fluctuation

As with all delirium tools, a delirium-positive result is not diagnostic. In every case the diagnosis is reached by clinical judgement.