Association between fluctuations in serum chloride levels and 30-day mortality among critically ill patients: a retrospective analysis

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
Variables	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.

ISSN: 1471-2253