ToolsCalculators
4 A's Test (4AT) for delirium screening
Rapid bedside screen for delirium and cognitive impairment in older adults.
4 A's Test (4AT) for delirium screening
Alertness
AMT4 errors (age, date of birth, place, current year)
Attention (months of the year backwards from December)
Acute change or fluctuating course in alertness, cognition, or other mental function over the past 2 weeks, still evident in the last 24 hours
Result0 points
Delirium or severe cognitive impairment unlikely (does not exclude milder cognitive impairment or fluctuating delirium).
- 4AT score (of 12)
- 0
When to use
- Rapid screening for delirium in acutely unwell or hospitalised older adults, including patients too drowsy or inattentive for formal cognitive testing.
Formula
Sum of 4 items: Alertness (0 or 4), AMT4 errors (0-2), Attention/months backwards (0-2), Acute or fluctuating change (0 or 4). Range 0-12; >=4 suggests possible delirium.
Pearls and pitfalls
- Designed to be completed in under 2 minutes without special training.
- An 'untestable' patient still generates a valid, high score rather than a missing result.