Table 4.

Cox proportional hazards models of the association of the plasma sulfate concentration, 24-h urinary excretion of sulfate, fractional excretion of sulfate, and sulfate clearance with disease outcome in CHF

Model	HR (95% CI)	P Value
1: Plasma sulfate concentration*	4.45 (1.94–10.2)	<0.001‡
2: 24-h Urinary sulfate excretion	0.58 (0.39–0.89)	0.012‡
3: Fractional excretion of sulfate*	0.55 (0.26–1.19)	0.130
4: Sulfate clearance	0.38 (0.23–0.63)	<0.001‡

For normally distributed data the HR is presented per SD increase. CHF, chronic heart failure; HR, hazard ratio; CI, confidence interval.

^*For logarithmically transformed skewed data the HR is presented per doubling. ‡Significant P value.