Table 2.

One-year unadjusted mortality hazard ratios (95% confidence intervals) associated with baseline and with time-dependent serum sodium levels of <130 , 130-135.9 and >145 mEq/L, compared to 136-145 mEq/L in the first, second, third, fourth and fifth year of follow-up, conditional on surviving to the beginning of the examined year.

			Year of follow-up
			1	2	3	4	5
Serum sodium (mEq/L)	Baseline	<130	1.14 (0.93-1.40)	0.99 (0.85-1.17)	1.04 (0.90-1.21)	1.30 (1.11-1.51)	1.13 (0.95-1.33)
	Time-dependent	<130	2.00 (1.67-2.38)	2.04 (1.81-2.30)	2.05 (1.82-2.30)	1.63 (1.43-1.86)	1.32 (1.15-1.51)
	Baseline	130-135.9	1.03 (0.98-1.09)	1.05 (1.01-1.09)	1.06 (1.03-1.10)	1.04 (1.01-1.08)	1.06 (1.02-1.09)
	Time-dependent	130-135.9	1.34 (1.27-1.41)	1.28 (1.23-1.32)	1.30 (1.26-1.34)	1.27 (1.23-1.32)	1.17 (1.13-1.21)
	Baseline	>145	1.09 (0.94-1.27)	1.18 (1.08-1.29)	1.17 (1.08-1.27)	1.12 (1.02-1.22)	1.02 (0.93-1.11)
	Time-dependent	>145	1.40 (1.20-1.64)	1.40 (1.28-1.53)	1.37 (1.27-1.49)	1.30 (1.19-1.42)	1.20 (1.10-1.31)

Hazard ratios are estimated from Cox models that included both baseline and time-dependent serum sodium categories, and were adjusted for age, gender, race, geographic location, diabetes mellitus, ASCVD, CHF, liver disease, malignancy, depression, the Charlson comorbidity index, systolic blood pressure, eGFR, serum albumin, alkaline phosphatase, aspartate and alanine aminotransferase, total bilirubin, blood hemoglobin, glucose and white blood cell count. Baseline serum sodium categories were established based on measurements in the first three months of cohort participation for all models and kept constant throughout follow-up. Time-dependent serum sodium categories were established using repetitive quarterly serum sodium levels measured throughout follow-up.