Table 3.

Subgroup analysis according to the cumulative fluid balance group within 72 h after ICU admission and dyschloremia upon ICU admission

Variables	Multivariable model
	Hazard Ratio (95% CI)	P *
aCumulative FB group (subgroup analysis 1)
Even (0–5%): 9680
bPositive fluctuation of Cl− > 10 mmol L− 1	1.76 (1.12, 2.78)	0.015
cNegative fluctuation of Cl− > 10 mmol L− 1	1.01 (0.46, 2.21)	0.986
Negative (< 0%): 3933
bPositive fluctuation of Cl− > 10 mmol L− 1	1.34 (0.64, 2.83)	0.441
cNegative fluctuation of Cl− > 10 mmol L− 1	3.04 (1.32, 7.03)	0.009
Positive, Mild to moderate (5–10%): 3889
bPositive fluctuation of Cl− > 10 mmol L− 1	1.31 (0.79, 2.17)	0.289
cNegative fluctuation of Cl− > 10 mmol L− 1	1.02 (0.50, 2.05)	0.967
Positive, Severe (> 10%): 1323
bPositive fluctuation of Cl− > 10 mmol L− 1	2.07 (1.35, 3.16)	0.001
cNegative fluctuation of Cl− > 10 mmol L− 1	1.30 (0.80, 2.11)	0.287
Dyschloremia on ICU admission (subgroup analysis 2)		P **
Normochloremia (97–110 mmol L− 1): 11,861
bPositive fluctuation of Cl− > 10 mmol L− 1	2.59 (1.74, 3.86)	< 0.001
cNegative fluctuation of Cl− > 10 mmol L− 1	1.00 (0.61, 1.66)	0.993
Hypochloremia (< 97 mmol L− 1): 1753
bPositive fluctuation of Cl− > 10 mmol L− 1	1.03 (0.69, 1.53)	0.903
cNegative fluctuation of Cl− > 10 mmol L− 1	4.66 (1.39, 15.65)	0.012
Hyperchloremia (> 110 mmol L− 1): 5211
bPositive fluctuation of Cl− > 10 mmol L− 1	1.75 (1.11, 2.74)	0.014
cNegative fluctuation of Cl− > 10 mmol L− 1	1.50 (0.93, 2.40)	0.095

A P^* < 0.012 and P^** < 0.017 indicate statistical significance after Bonferroni correction in analyses of four subgroups

ICU intensive care unit, FB fluid balance

^aCumulative fluid balance (%): (Total input fluid – total output fluid, L) × 100 x weight at admission (kg)^− 1

^bPositive fluctuation in Cl⁻: (Maximum Cl⁻ – Preadmission Cl⁻) for 72 h after ICU admission.

^cNegative fluctuation in Cl⁻: (Preadmission Cl⁻ – Minimum Cl⁻) for 72 h after ICU admission.