Rapid Assessment Test for Delirium (4AT)

The 4AT detects delirium at the bedside in under two minutes, using four items that each begin with an A.

Alertness is observed rather than asked: normal scores 0, clearly abnormal — drowsy, agitated, hyper-alert, or fluctuating — scores 4. The AMT4 asks four orientation questions: age, date of birth, place, and year. Attention asks the person to say the months of the year backwards from December. Acute change or fluctuating course asks whether there has been a recent change in alertness, cognition, or mental function, drawing on staff or family report. Totals run 0 to 12. Four or more suggests possible delirium; 1 to 3 suggests possible cognitive impairment.

Licensing Notes: Free to use under a Creative Commons BY-NC-SA license, hosted at the4at.com with translations in several languages. No special training is required.

Learn More: The scoring is not linear — the threshold of 4 can be crossed three different ways: a positive alertness item alone, a positive acute-change item alone, or a combination of poor or untestable cognitive items. That structure means a drowsy patient who cannot be tested still produces a meaningful score. A score of 0 means delirium is unlikely at this assessment, not excluded. If staff or family report fluctuation, repeat it at a different time of day.