The 4AT is a screening test for delirium and cognitive impairment.
Parameters:
(1) alertness
(2) abbreviated mental test of orientation (age, date of birth, current location, current year)
(3) attention, by repeating months of the years backwards
(4) acute change or fluctuating course in altertness, cognition or mental function arising over the last 2 weeks
|
Parameter
|
Finding
|
Points
|
|
alertness
|
fully alert
|
0
|
|
|
mild sleepiness for < 10 minutes after waking then normal
|
0
|
|
|
clearly abnormal
|
4
|
|
abbreviated mental test
|
all correct
|
0
|
|
|
1 mistake
|
1
|
|
|
>= 2 mistakes or untestable
|
2
|
|
attention
|
achieves >= 7 correctly
|
0
|
|
|
< 7 correct or refuses to start
|
1
|
|
|
untestable
|
2
|
|
acute change or fluctuating course
|
no
|
0
|
|
|
yes
|
4
|
total score =
= SUM(points for all 4 parameters)
Interpretation:
• minimum score: 0
• maximum score: 12
|
Score
|
Interpretation
|
|
>= 4
|
possible delirium
|
|
1 to 3
|
possible cognitive impairment
|
|
0
|
delirium or severe cognitive impairment unlikely
|
Performance:
• The area under the ROC curve is 0.90 to 0.93.
