Table 1.

Characteristics of study patients

Characteristics	All patients	Delirium	No delirium recorded*	P
Total number of patients	627	68	559
Sex, female	250 (39.9%)	21 (30.9%)	229 (41%)	0.11
Weight (kg), mean (SD)†	82.3 ± 23.2	83.3 ± 23.2	82.2 ± 23.2	0.72
Age (years), median (IQR)	62 (48–72)	67 (50.5–75.5)	62 (48–71)	0.05
APACHE II, median (IQR)‡	16 (12–21)	17 (13–22)	16 (12–21)	0.09
Days from ICU admission to study day, median (IQR)	3 (1–7)	4 (1.5–8.5)	3 (1–6)	0.05
Source of ICU admission				0.60
Emergency department	199 (31.6%)	20 (29.4%)	179 (31.9%)
Operating theatre after elective surgery	131 (20.8%)	15 (22.1%)	116 (20.7%)
Ward	126 (20%)	11 (16.2%)	115 (20.5%)
Operating theatre after emergency surgery	93 (14.8%)	12 (17.6%)	81 (14.4%)
Other ICU	39 (6.2%)	3 (4.4%)	36 (6.4%)
Other hospital (except from other ICU)	39 (6.2%)	7 (10.3%)	32 (5.7%)
Previous ICU admission in this hospital admission	42 (6.7%)	5 (7.4%)	37 (6.6%)	0.82
Invasive mechanical ventilation‡, §	286 (45.7%)	32 (47.1%)	254 (45.5%)	0.81
Respiratory support¶	165 (26.3%)	22 (32.4%)	143 (25.6%)	0.23

APACHE = Acute Physiological and Chronic Health Evaluation; ICU = intensive care unit; IQR = interquartile range; SD = standard deviation.

^*Includes patients who have been screened as not delirious and those not screened.

^†n = 614.

^‡n = 626.

^§At any point during the study day.

^¶Using supplemental high flow nasal prongs, continuous positive airway pressure or bi-level airway pressure at any point during the study day.