Table 2.

Associations between pre-dialysis serum K and clinical outcomes

		HR (95% CI), All-cause mortality		HR (95% CI), Arrhythmia composite^
Serum K (mEq/L)	N patients (%)	Unadjusted	Adjusted*	Unadjusted	Adjusted*
< 4.0	6153 (11%)	1.18 (1.12–1.24)	1.03 (0.97–1.09)	0.99 (0.88–1.11)	0.94 (0.83–1.05)
4.0 – 5.0	27107 (50%)	1 (Ref.)	1 (Ref.)	1 (Ref.)	1 (Ref.)
5.1 – 5.5	10635 (20%)	0.95 (0.91–0.99)	1.02 (0.97–1.07)	0.97 (0.89–1.07)	1.00 (0.91–1.10)
5.6 – 6.0	6238 (11%)	1.02 (0.96–1.08)	1.13 (1.06–1.20)	1.05 (0.95–1.17)	1.07 (0.96–1.20)
> 6.0	4403 (8%)	1.00 (0.93–1.07)	1.12 (1.04–1.21)	1.16 (1.02–1.32)	1.21 (1.05–1.38)

HR: Hazard ratio; Cox models stratified by DOPPS phase, country, US large dialysis organization (all-cause mortality only), and accounted for facility clustering.

^{^}Arrhythmia composite includes sudden death or arrhythmia-related hospitalizations.

For the arrhythmia composite outcome, 45,511 patients (3300 events, 7%) were eligible for the analysis after excluding facilities where cause of death and/or hospitalization was not obtained.

^*Adjustments: age, sex, vintage, 13 comorbidities, vascular access, BMI, albumin, nPCR, serum Ca, serum phosphorus, serum phosphorus squared, serum bicarbonate, dialysate bicarbonate, hemoglobin, treatment time, Kt/V.