Table 2. Univariate and multivariate Cox regression models of all-cause and CVD-related mortality for RDW groups.

	All-cause mortality		CVD mortality
	Hazard ratio (95% CI)	p-value	Hazard ratio (95% CI)	p-value
RDW median
unadjusted model	2.95 (1.88, 4.64)	<0.001	3.06 (1.64, 5.71)	<0.001
Model 1	2.23 (1.41, 3.54)	0.001	2.48 (1.32, 4.69)	0.005
Model 2	2.36 (1.48, 3.78)	<0.001	2.69 (1.41, 5.13)	0.003
Model 3	2.60 (1.59, 4.26)	<0.001	3.38 (1.72, 6.67)	<0.001
Model 4	2.82 (1.72, 4.64)	<0.001	3.60 (1.8, 7.22)	<0.001
Model 5	2.58 (1.31, 5.09)	0.006	3.48 (1.44, 8.43)	0.006
(B) sensitivity tests
(i) RDW as a continuous variable	1.15 (1.00, 1.33)	0.047	1.22 (1.00, 1.48)	0.049
(ii) optimal RDW by ROC analysis	2.74 (1.56, 4.81)	<0.001	3.26 (1.44, 7.39)	0.004
(iii) RDW tertiles
First tertile	1		1
Second tertile	1.34 (0.62, 2.93)	0.457	2.03 (0.62, 6.62)	0.241
Third tertile	2.41 (1.07, 5.44)	0.034	5.21 (1.46, 18.64)	0.011
p-trend		0.023		0.008

Model 1: RDW, age, sex, BMI and smoking status.

Model 2: Model 1 plus medications (ACE inhibitors/ARB, iron preparation, folic acid, and vitamin B12 supplement, erythropoiesis stimulating agents, and calcium supplement).

Model 3: Model 2 plus comorbidities (diabetes mellitus, hypertension, cancer, dementia and chronic lung disease, liver cirrhosis, hyperlipidemia and cardiovascular disease).

Model 4: Model 3 plus PD related parameters (weekly total Kt/V urea, nPNA, D/P creatinine at 4 hours, ultrafiltration, 24-hour urine output, and residual renal function.).

Model 5: model 4 plus laboratory data (BUN, creatinine, albumin, GPT, WBC counts, alkaline phosphate, hemoglobin, ferritin, transferrin saturation, cholesterol, triglyceride, intact PTH, calcium, and phosphate).