Q: How often should the 4AT be repeated in at-risk patients?

Once daily for inpatients is appropriate. Repeat 4AT should also be performed if there is a change in clinical status, after starting or stopping a deliriogenic medication, or post-operatively. Twice-daily screening may be appropriate in ICU, post-operative, or high-risk settings.

Question 1

Can the 4AT be used in patients with dementia?

Accepted Answer

Yes — the 4AT is validated in populations with pre-existing cognitive impairment. However, a score of 1–3 may reflect baseline impairment rather than delirium. The acute change item (Item 4) is crucial for distinguishing delirium superimposed on dementia. Collateral history from a relative or carer is essential.

Question 2

What if the patient refuses to answer the AMT4 questions?

Accepted Answer

Refusal to engage is itself clinically significant. Score the AMT4 as '2' (two or more errors / untestable). The attention item and the alertness observation still contribute useful information. A score ≥4 even without complete AMT4 data may still indicate possible delirium.

Question 3

Is the 4AT superior to the Confusion Assessment Method (CAM)?

Accepted Answer

The 4AT and CAM have comparable diagnostic accuracy. The 4AT is simpler to administer (<2 min vs 5–10 min), does not require rater training, and includes an objective cognitive test. The CAM remains the reference standard for research. For clinical screening, the 4AT is more practical.

Question 4

How often should the 4AT be repeated in at-risk patients?

Accepted Answer

Once daily for inpatients is appropriate. Repeat 4AT should also be performed if there is a change in clinical status, after starting or stopping a deliriogenic medication, or post-operatively. Twice-daily screening may be appropriate in ICU, post-operative, or high-risk settings.