Table 4.

Univariate Cox proportional hazards analyses for 28-day all-cause mortality per 1 mEq/L increase of chloride concentration in normochloremic group.

Variables (n = 498)	HR (95% CI)	p-value
Delta chloride for 24 hours (ΔCl24h)	0.879 (0.821–0.942)	<0.001
Delta chloride for 48 hours (ΔCl48h)	0.903 (0.842–0.967)	0.004
Delta chloride for 72 hours (ΔCl72h)	0.895 (0.837–0.957)	0.001

Abbreviations; HR, hazard ratio; CI, confidence interval. Definitions; The 24 hour delta chloride concentration (ΔCl_24h) (mEq/L) was calculated by the following formula: [Cl_24h] − [Cl_{at baseline}], where Cl_24h is the chloride concentration at 24 hour, and Cl_{at baseline} is the baseline chloride concentration. The 48 hour delta chloride concentration (ΔCl_48h) (mEq/L) was calculated by the following formula: [Cl_48h] − [Cl_{at baseline}], where Cl_48h is the chloride concentration at 48 hour, and Cl_{at baseline} is the baseline chloride concentration. The 72 hour delta chloride concentration (ΔCl_72h) (mEq/L) was calculated by the following formula: [Cl_72h] − [Cl_{at baseline}], where Cl_72h is the chloride concentration at 72 hour, and Cl_{at baseline} is the baseline chloride concentration.