4AT delirium screening calculator

The 4AT is a brief tool for delirium detection designed for use in clinical practice. It is the standard tool for delirium detection in many countries. It is recommended in multiple guidelines and pathways.

It incorporates the Months Backwards test and the Abbreviated Mental Test - 4 (AMT4), which are short tests for cognitive impairment. This provides basic cognitive testing, aimed at detecting moderate-severe cognitive impairment, alongside assessment for delirium. See https://www.the4at.com/guide.

Please click on the appropriate response to each question, then click on “Calculate”

Question
Please select your answer

1. Alertness

This includes patients who may be markedly drowsy (eg difficult to rouse and/or obviously sleepy during assessment) or agitated/hyperactive.

Observe the patient:
If asleep, attempt to wake with  speech or gentle touch on shoulder. Ask the patient to state their name and address to assist rating.


2. AMT4

Ask the patient to state:
Age, date of birth, place (name of the hospital or building), current year


3. Attention

Ask the patient:
"Please tell me the months of the year in backwards order, starting at December."

To assist initial understanding one prompt of "what is the month before December?" is permitted.


4. Acute change or fluctuating course

Evidence of significant change or fluctuation in: alertness, cognition, other mental function (eg paranoia, hallucinations) arising over the last 2 weeks and still evident in last 24hrs


How to interpret AMT4

AMT4 is not a full cognitive test and decisions should not be made on this basis. A high AMT4 score can indicate general cognitive impairment, but note that a low score does not rule out mild cognitive impairment.

How to score acute change or fluctuating course

This item requires information from one or more sources – eg a GP letter, personal knowledge of the patient, key informant such as family member, deduction from other information in patient history (for example, if the patient is drowsy and usually functions independently, the clinician may decide that this indicates acute change). If you do not have sufficient information, leave this element blank and click on “Calculate.”

Regulatory Information

Product Name: Calculator Suite
Calculator Name: 4AT - 4 A's Assessment test for delirium and cognitive impairment
Calculator Version: v2.0.0

InnoScot Health

InnoScot Health
272 Bath Street
Glasgow
Scotland
G2 4JR

UK Conformity Assessed

InnoScot Health

Calculators are not intended to be used by members of the public as a substitute for professional advice.