Table 1.

Patient characteristics of all intensive care unit admitted patients within the period 2011 to 2016 categorised by atrial fibrillation status

Characteristic	Total population (n=3334)		No AF (n=2538)		AF known (n=583)		New-onset AF* (n=213)
Age, median (range)	69	(12–99)	67†‡	(12–99)	7†	(31–99)	76‡	(41–97)
Female, n (%)	1426	(42.8)	1100	(43.3)	251	(43.1)	75	(35.2)
APACHE II, median (range)	15	(1–50)	14‡†	(1–50)	18†§	(3–44)	19‡§	(5–46)
APACHE III median (range)	57	(6–200)	52‡†	(6–200)	70†§	(17–182)	75‡§	(26–191)
LOS ICU, median (range)	2	(0.1–100)	2‡†	(0.1–85)	2†§	(0.1–100)	7‡§	(0.3–95)
LOS hospital, median (range)	10	(0.1–196)	9‡†	(0.1–128)	11†§	(0.1–196)	16‡§	(0.3–96)
Reason for ICU admission, n (%)
Medical	1834	(55.0)	1358‡†	(53.5)	345†‡§	(59.2)	131‡§	(62.7)
Urgent surgery	493	(14.8)	354‡†	(14.0)	92†‡§	(15.8)	47‡§	(22.5)
Planned surgery	1001	(30.0)	824‡†	(32.5)	146†‡§	(25.0)	31‡§	(14.8)
Missing			2	(<0.01)			4	(1.2)

*The group 'new-onset AF’ includes documented and non-documented AF.

†Significant difference between no AF group and known AF group (p<0.05).

‡Significant difference between new-onset AF group and no AF group (p<0.05).

§Significant difference between new-onset AF group and known AF group (p<0.05).

AF, atrial fibrillation; APACHE, Acute Physiology and Chronic Health Evaluation; ICU, intensive care unit; LOS, length of stay.