Table 2.

Cox regression analysis

	Univariate		Simple Adjustmenta		Extended Adjustmentb
	HR (95% CI)	P	HR (95% CI)	P	HR (95% CI)	P
Including only main effects of phosphorus and albumin
phosphorus (mmol/L)	1.09 (0.75 to 1.58)	0.67	1.47 (0.96 to 2.25)	0.08	1.57 (0.97 to 2.54)	0.07
albumin (g/dl)	0.21 (0.15 to 0.29)	<0.001	0.19 (0.13 to 0.28)	<0.001	0.23 (0.14 to 0.36)	<0.001
Including main effects of phosphorus and albumin + interaction effect
phosphorus-albumin				0.004		0.01

Hazard ratios (HRs), 95% confidence intervals (CIs), and P-values of continuous and time-varying phosphorus and albumin concentrations as well as of their interaction term each in a univariate Cox model, in a simple adjustment model (adjusted for age, gender, and type of dialysis therapy) and an extended adjustment model (adjusted for age, gender, type of dialysis therapy, C-reactive protein, hemoglobin, calcium, and immunoreactive parathyroid hormone [iPTH]) on all-cause mortality risk.

^aAdjusted for age, gender, type of dialysis therapy.

^bAdjusted for age, gender, type of dialysis therapy, C-reactive protein, hemoglobin, calcium, and iPTH.