Question 1

What is the 4AT?

Accepted Answer

The 4AT is a brief assessment tool designed to help with the detection of delirium in clinical settings. It consists of four items: (1) Alertness, (2) AMT4 (a brief cognitive test), (3) Attention, and (4) Acute change or fluctuating course. The 4AT takes less than 2 minutes to complete and does not require special training. It produces a score from 0–12, with a score of 4 or more suggesting possible delirium.

Question 2

What does the 4AT acronym stand for?

Accepted Answer

4AT is short for the "4 A’s Test", where the four A’s are Alertness, AMT4, Attention, and Acute change or fluctuating course.

Question 3

Who developed the 4AT and when?

Accepted Answer

The 4AT was developed by a multidisciplinary team led by Prof. Alasdair MacLullich at the University of Edinburgh, UK. The first version was released in 2011, with the current Version 1.2 published in 2014.

Question 4

What is the target population for the 4AT?

Accepted Answer

The 4AT is designed for use in adults (≥18 years) in all clinical settings, including emergency departments, medical and surgical wards, ICU, rehabilitation units, and nursing homes. It is particularly recommended for use in older adults (≥65 years) who are at higher risk of delirium. The 4AT is not validated for use in children or adolescents.

Question 5

Is the 4AT free to use? Do I need permission or registration?

Accepted Answer

Yes. The 4AT is free of charge. It is released under a Creative Commons Attribution 4.0 (CC BY 4.0) licence, so it can be used, reproduced, and adapted provided the original source (www.the4at.com) is credited. No permission, payment, or registration is required.

Question 6

What guidelines recommend the 4AT?

Accepted Answer

The 4AT is included in multiple national and international clinical guidelines, including: UK NICE Guideline CG103 on Delirium (2010, updated 2023); Scottish Intercollegiate Guidelines Network (SIGN) guideline on Risk Reduction and Management of Delirium (2019); European Society of Anaesthesiology and guideline on Post‑operative Delirium (2017); Australian Commission on Safety and Quality in Health Care (2016); Healthcare Improvement Scotland Delirium Toolkit; British Geriatrics Society guidance; American Psychiatric Association Practice Guideline on Delirium (2025); Canadian Coalition for Seniors’ Mental Health guideline; and the Irish National Clinical Guideline on Delirium.

Question 7

How is the total score of the 4AT reached?

Accepted Answer

The total 4AT score is the sum of the four items:
- Item 1 (Alertness): Normal = 0, Mild sleepiness = 0, Clearly abnormal = 4.
- Item 2 (AMT4): No mistakes = 0, 1 mistake = 1, 2+ mistakes or untestable = 2.
- Item 3 (Attention): Achieves 7+ months correctly = 0, Starts but scores <7 months or refuses = 1, Untestable = 2.
- Item 4 (Acute change or fluctuating course): No = 0, Yes = 4.
The total score ranges from 0 to 12.

Question 8

What do the different 4AT scores mean?

Accepted Answer

Interpretation:
- 0: Delirium or severe cognitive impairment unlikely (but still possible if information is incomplete).
- 1–3: Possible cognitive impairment; more detailed cognitive testing and/or informant history advised.
- 4 or above: Possible delirium ± cognitive impairment; clinical assessment required to confirm diagnosis. A score of 4 or above suggests possible delirium but is not diagnostic by itself.

Question 9

What is the AMT4?

Accepted Answer

The AMT4 (Abbreviated Mental Test – 4) is a brief cognitive test comprising four questions: 1. Age; 2. Date of birth; 3. Place (name of the hospital or building); 4. Current year. Each correct answer scores 0, and each incorrect answer scores 1. A total score of 0 indicates all answers were correct, 1 indicates one error, and 2 indicates two or more errors or if the patient is untestable.

Question 10

How should I interpret the "acute change or fluctuating course" item?

Accepted Answer

Item 4 assesses whether there has been a significant change in the patient's mental status from their baseline state or if symptoms have been fluctuating in the past 2 weeks. Information should be obtained from someone who knows the patient well. Score 4 for acute change or fluctuation, 0 if none.

Question 11

What is the sensitivity and specificity of the 4AT?

Accepted Answer

As of 2024, a systematic review pooling ≥33 validation studies (>6,000 patients) reported a sensitivity of 88% (95% CI 80–93%) and a specificity of 88% (95% CI 82–92%).

Question 12

What if a patient is unable to complete parts of the 4AT?

Accepted Answer

If Items 2 or 3 are untestable (e.g., the patient is too drowsy), score each as 2 points. Abnormal alertness (Item 1) scores 4. Item 4 can usually be answered using collateral history.

Question 13

Can the 4AT detect subsyndromal delirium?

Accepted Answer

The 4AT is not specifically designed for subsyndromal delirium (SSD), but SSD cases often score 1–3, prompting further assessment. Research on SSD detection remains limited.

Question 14

What are the limitations of the 4AT? Can it give false positives or false negatives?

Accepted Answer

False positives (score ≥4 without delirium) can occur in severe dementia or when there are communication barriers. False negatives (score <4 with delirium) can occur during lucid intervals or mild delirium. Use collateral history, clinical context, and repeat assessment if suspicion remains.

Question 15

How long does it take to do the 4AT?

Accepted Answer

The 4AT usually takes less than 2 minutes to complete in routine practice.

Question 16

Who can administer the 4AT, and is specific training required?

Accepted Answer

Any healthcare professional can administer the 4AT. No specific training or certification is required—only familiarity with the tool and delirium features.

Question 17

How often should the 4AT be used? When and in what settings should I use it?

Accepted Answer

Use the 4AT at key points: on admission, perioperatively, at care transitions, when delirium is suspected, or to track recovery. Routine multiple daily use is not generally required.

Question 18

How should administration be adapted for patients with communication difficulties?

Accepted Answer

For patients who are untestable, score cognitive items (Item 2 and Item 3) as 2 points each. Observe alertness for Item 1 and obtain collateral information for Item 4. Use interpreters, writing, or communication aids as needed; if impossible, mark as untestable.

Question 19

Can the 4AT be used in patients with known dementia?

Accepted Answer

Yes. The 4AT is validated for delirium superimposed on dementia, though specificity may be lower in advanced dementia. Rely on Item 4 and informant history to distinguish from baseline.

Question 20

Is the 4AT available in other languages?

Accepted Answer

Yes. Validated translations exist in many languages, including Italian, German, Spanish, Portuguese, Danish, French, Icelandic, Norwegian, Arabic, Finnish, Czech, Dutch, Polish, Swedish, Mandarin, Cantonese, Turkish, Korean, Thai, Russian, Hebrew, and Japanese.

Question 21

Can the 4AT be integrated into Electronic Health Records (EHR/EMR)?

Accepted Answer

Yes. The 4AT is free to embed in any EHR or EMR without licensing fees.

Question 22

What are the benefits of implementing the 4AT tool in hospitals?

Accepted Answer

Benefits include early delirium detection, improved outcomes such as shorter length of stay and lower mortality, ease of use, no training requirement, and identification of high‑risk patients.

Question 23

How can we implement the 4AT in our clinical workflow and ensure it is used effectively?

Accepted Answer

Integrate the 4AT into routine assessments (e.g., admission, clinical status changes), provide brief staff training sessions, define clear protocols for positive screens (e.g., score ≥4 triggers review), and audit usage regularly.

Question 24

How does the 4AT compare to the Confusion Assessment Method (CAM)?

Accepted Answer

In a large prospective UK randomized controlled trial (RCT) diagnostic test accuracy study (BMC Medicine 2019; https://bmcmedicine.biomedcentral.com/articles/10.1186/s12916-019-1367-9) the 4AT showed sensitivity 76% and specificity 94%, while CAM showed sensitivity 40% and specificity 100% when both were applied by the same trained assessors. Meta‑analyses indicate pooled 4AT sensitivity around 88% and specificity around 88% (https://academic.oup.com/ageing/article/50/3/733/5974849); CAM accuracy varies with assessor training, with lower sensitivity in routine clinical practice when performed by staff without adequate training. The 4AT takes less than 2 minutes and requires no training, whereas CAM takes about 5 minutes and does require training.

Question 25

How does the 4AT compare to the NuDESC?

Accepted Answer

NuDESC is an observational tool applied over nursing shifts (five domains). Reported sensitivity ranges from 29% to 32% at a threshold ≥2 (specificity 92–96%), whereas the 4AT combines cognitive testing and observation, with pooled sensitivity and specificity of about 88% each, and is suitable for point‑in‑time assessments such as admission.

Question 26

How does the 4AT compare to the Delirium Observation Screening Scale (DOSS)?

Accepted Answer

The DOSS is designed for ongoing monitoring (reported sensitivity 25–97%, specificity 89–98%), while the 4AT is a rapid point‑in‑time assessment that requires no training and has more consistent accuracy across validation studies.

Question 27

How does the 4AT compare to the Brief CAM (bCAM)?

Accepted Answer

Both the bCAM and 4AT take less than 2 minutes. The bCAM (sensitivity 78–84%, specificity 96–97%) benefits from training and provides a binary result, while the 4AT needs no training and provides a score range.

Question 28

How does the 4AT compare to the Ultra‑Brief CAM (UB‑CAM)?

Accepted Answer

The UB‑CAM is a two-step tool. It is faster than the standard CAM but still requires training. The 4AT is a single‑step, no‑training tool with much broader validation and clinical implementation evidence and similar performance.

Question 29

How does the 4AT compare to the 3D‑CAM?

Accepted Answer

The 3D‑CAM (sensitivity about 95%, specificity about 94%) requires training and more time (≈3 minutes); the 4AT offers comparable performance, faster administration (<2 minutes), and broader validation without training.

Question 30

How does the 4AT compare to the Single Question in Delirium (SQiD)?

Accepted Answer

The SQiD uses a single informant question (e.g., "Is this patient more confused than before?"). It is very quick but not validated as a standalone diagnostic tool. The 4AT is multi‑component, validated, and provides a graded score.

Question 31

What are the key advantages of the 4AT?

Accepted Answer

Key advantages include: speed (<2 minutes); no training required; inclusivity of untestable patients; the largest validation evidence base among short delirium tools; endorsement in international guidelines; and free accessibility under CC BY 4.0.

4AT: Frequently Asked Questions

General Information on the 4AT

What is the 4AT?

What does the 4AT acronym stand for?

What are the key features of the 4AT?

What does the 4AT acronym stand for?

Who developed the 4AT and when?

What is the target population for the 4AT?

Is the 4AT free to use? Do I need permission or registration?

What guidelines include the 4AT?

Scoring & Interpretation

What do the different 4AT scores mean?

How is Item 1 (Alertness) scored?

How is Item 2 (AMT4) scored?

How is Item 3 (Attention) scored?

How is Item 4 (Acute Change or Fluctuating Course) scored?

What if a patient is unable to complete parts of the 4AT?

Evidence & Validation Studies on the 4AT

What is the sensitivity and specificity of the 4AT?

Practical Use & Clinical Implementation

Comparisons with Other Tools