4-AT
ALERTNESS
Drowsy (e.g. difficult to rouse and/or obviously sleepy) or agitated/hyperactive. Observe the patient. If asleep, attempt to wake. Ask the patient to state their name and address to assist rating.
- Normal (fully alert, but not agitated, throughout assessment) - 0
- Mild sleepiness for <10 seconds after waking, then normal - 0
- Clearly abnormal - 4
AMT4
Age, date of birth, place (name of the hospital or building), current year.
- No mistakes - 0
- 1 mistake - 1
- 2 or more mistakes/untestable - 2
ATTENTION
Months of the year backwards One prompt of “what is the month before December?” is permitted.
- Achieves 7 months or more correctly - 0
- Starts but scores <7 months / refuses to start - 1
- Untestable (cannot start because unwell, drowsy, inattentive) - 2
ACUTE CHANGE OR FLUCTUATING COURSE
Evidence of significant change or fluctuation arising over the last 2 weeks
- No - 0
- Yes - 4
4AT SCORE
- 4 or above: possible delirium +/- cognitive impairment
- 1-3: possible cognitive impairment
- 0: delirium or severe cognitive impairment unlikely (but delirium still possible if acute change information incomplete)