4AT — Assessment test for delirium & cognitive impairment
Rapid initial assessment for possible delirium and cognitive impairment.
Reference information · Questionnaire
- Last content update
- 2026-10-26
- Clinical review
- Not independently reviewed
- Source jurisdiction
- See individual sources
- Coverage
- Questionnaire
| Field | Instrument context |
|---|---|
| Version | 1.2 (October 2014); digital transcription |
| Population | Adults aged 18 years and older; bedside clinical assessment. |
| Respondent | clinician |
| Recall period | Items 1–3: at assessment. Item 4: change arising over the last 2 weeks and still evident in the last 24 hours. |
| Purpose | Rapid initial assessment for possible delirium and cognitive impairment. |
A total does not establish individual item responses.
[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: 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. GUIDANCE NOTES: The 4AT is a screening instrument designed for rapid initial assessment of delirium and cognitive impairment. A score of 4 or more suggests delirium but is not diagnostic: more detailed assessment of mental status may be required to reach a diagnosis. A score of 1–3 suggests cognitive impairment and more detailed cognitive testing and informant history-taking are required. A score of 0 does not definitively exclude delirium or cognitive impairment: more detailed testing may be required depending on the clinical context. Items 1–3 are rated solely on observation of the patient at the time of assessment. Item 4 requires information from one or more source(s), eg. your own knowledge of the patient, other staff who know the patient (eg. ward nurses), GP letter, case notes, carers. The tester should take account of communication difficulties (hearing impairment, dysphasia, lack of common language) when carrying out the test and interpreting the score. Alertness: Altered level of alertness is very likely to be delirium in general hospital settings. If the patient shows significant altered alertness during the bedside assessment, score 4 for this item. AMT4 (Abbreviated Mental Test – 4): This score can be extracted from items in the AMT10 if the latter is done immediately before. Acute Change or Fluctuating Course: Fluctuation can occur without delirium in some cases of dementia, but marked fluctuation usually indicates delirium. To help elicit any hallucinations and/or paranoid thoughts ask the patient questions such as, “Are you concerned about anything going on here?”; “Do you feel frightened by anything or anyone?”; “Have you been seeing or hearing anything unusual?”
Responses stay in this page’s memory. Reset or leave the page to clear them. No patient identifiers are collected.
Interpretation & limitations
- A score ≥4 should prompt appropriate clinical assessment; the instrument does not establish a diagnosis.
- A score of 0 does not exclude delirium, especially if acute-change information is incomplete.
- Untestable AMT4 and attention ratings each score 2; inability to engage must not be scored as zero.
- Adapted from the 4AT © 2011–2014 Alasdair MacLullich, Tracy Ryan and Helen Cash. Licensed under CC BY 4.0: https://creativecommons.org/licenses/by/4.0/. Official and current version: https://www.the4at.com/. Changes: digital presentation and the zero-score interpretation label shortened with an explicit not-excluded qualifier; clinical component wording and score values retained. Published validation evidence for the official 4AT should not be assumed to apply automatically to a modified presentation. No warranty is given as to accuracy or fitness for purpose.
- Clinical judgement is required; no score declares safety or triggers an automatic diagnosis or treatment change.
- Communication barriers and severe pre-existing dementia may affect interpretation.
- Items are clinical ratings, not a patient self-report questionnaire.
- All four component scores are required by this application; obtain/review acute-change information rather than silently defaulting to No.
References · 3
- Official current English form
- 4AT user guide
- 4AT attribution and reuse · CC BY 4.0 permits copying, sharing and adaptation, including commercial use. Retain attribution, licence link, source link and disclaimer; identify modifications.