Table 1.

Baseline characteristics, exposures in ICU and outcomes

Category	Variables	IAH cases (n=121)	Non-IAH cases (n=1635)	p Value
Characteristics	Age (years)	71 (61–78)	69 (58–79)	0.38
	Male	85 (70.3)	1016 (62.1)	0.075
	APACHE-II score	19 (13–24)	12 (8–18)	<0.001*
Main symptom at ICU admission	Sepsis	45 (37.2)	343 (21.0)	<0.001*
	Respiratory failure	46 (38.0)	415 (25.4)	0.002*
	Neurological	45 (37.2)	501 (30.6)	0.13
	CVD	33 (27.3)	313 (19.1)	0.030*
	Non-CVD	12 (9.9)	188 (11.5)	0.60
	Acute kidney injury	45 (37.2)	358 (21.9)	<0.001*
	Other medical conditions	7 (5.8)	307 (18.8)	<0.001*
Interventions	Surgery prior to ICU admission			0.23
	Elective surgery	4 (3.3)	102 (6.2)
	Emergency surgery	26 (21.5)	278 (17.0)
	Renal replacement therapy	11 (9.1)	128 (7.8)	0.62
	Mechanical ventilation	86 (71.1)	606 (37.1)	<0.001*
Outcomes	Length of ICU admission (days)	9 (5,15)	4 (3,6)	<0.001*
	All-cause hospital mortality	56 (46.3)	193 (11.9)	<0.001*
	All-cause 28-day mortality	42 (35.0)	145 (8.9)	<0.001*

Continuous data are presented as the median (IQR). Categorical data are presented as n (%).

*p<0.05.

APACHE, Acute Physiology And Chronic Health Evaluation; CVD, cerebrovascular disease; IAH, ICU-acquired hypernatraemia; ICU, intensive care unit.