4AT Delirium Screen
4AT rapid delirium screen (MacLullich 2019): abnormal alertness (0 or 4), AMT4 errors (0/1/2), attention by months backwards (0/1/2), acute change or fluctuating course (0 or 4); total 0-12, >= 4 possible delirium.
Open the calculator → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.
Example
- Alertness clearly abnormal (drowsy or agitated)
- No
- AMT4 errors
- >=2 errors / untestable (2)
- Attention, months backwards
- Untestable (2)
- Acute change or fluctuating course
- Yes
Result: 4AT 8 of 12: possible delirium +/- cognitive impairment per MacLullich 2019.
The tool opens with these values already filled in. Replace them with your own.
What the result means
- 0
- Delirium or significant cognitive impairment unlikely per MacLullich 2019.
- 1-3
- Possible cognitive impairment without delirium per MacLullich 2019.
- >=4
- Possible delirium +/- cognitive impairment per MacLullich 2019.
What you enter
- Alertness clearly abnormal (drowsy or agitated) (0 or 4)
- AMT4 errors (0 none / 1 one / 2 two or more or untestable)
- Attention, months backwards (0 reaches July / 1 starts but < 7 / 2 untestable)
- Acute change or fluctuating course (0 or 4)
How this is calculated
MacLullich AMJ, Shenkin SD, Goodacre S, et al. The 4 "A"s Test for detecting delirium in acute medical patients (4AT): a diagnostic accuracy study. Health Technol Assess. 2019;23(40):1-194. Read the source ↗
A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.