4AT (Rapid Delirium Screening)

4AT (Rapid Assessment Test for Delirium)

Brief four-item bedside tool (alertness, AMT4 orientation, months-backwards attention, acute change or fluctuation) for rapid screening of delirium and cognitive impairment, with higher totals prompting confirmatory clinical assessment; a screen, not a diagnosis.

Alertness

(observe throughout the assessment)

0 - Normal (fully alert, not agitated, throughout assessment) 0 - Mild sleepiness for under 10 seconds after waking, then normal 4 - Clearly abnormal (hyperalert; or drowsy / difficult to rouse; or unrousable)

AMT4 orientation

(age, date of birth, place [name of hospital or building], current year)

0 - No mistakes 1 - 1 mistake 2 - 2 or more mistakes, or untestable

Attention

(ask to say the months of the year in backwards order, starting from December)

0 - Achieves 7 months or more correctly 1 - Starts but scores fewer than 7 months, or refuses to start 2 - Untestable (cannot start because unwell, drowsy, or inattentive)

Acute change or fluctuating course

(evidence of significant change or fluctuation in alertness, cognition, or other mental function arising over the last 2 weeks and still evident in the last 24 hours)

0 - No 4 - Yes