Table 1.
Baseline characteristics of the training and testing cohorts.
| Characteristics | At dialysis initiation | 0-3 months | |||||||
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Training cohort (n=5351) | Testing cohort (n=5828) | Training cohort (n=4425) | Testing cohort (n=3729) | |||||
| Sex, n (%) |
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Male | 3295 (61.58) | 3524 (60.47) | 2744 (62.01) | 2264 (60.71) | ||||
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Female | 2056 (38.42) | 2304 (39.53) | 1681 (37.99) | 1465 (39.29) | ||||
| Body mass index (kg/m2), mean (SD)a | 22.09 (3.29) | 21.73 (3.07) | 22.19 (3.39) | 21.83 (3.04) | |||||
| Age at dialysis initiation (years), mean (SD) | 51.67 (16.48) | 62.53 (16.20) | 52.61 (16.59) | 62.45 (15.9) | |||||
| Systolic pressure (mmHg), mean (SD) | 137.49 (22.93) | 146.18 (24.58) | 138.52 (23.15) | 146.33 (24.68) | |||||
| Diastolic pressure (mmHg), mean (SD) | 77.76 (12.26) | 78.95 (15.52) | 80.45 (12.15) | 79.02 (15.45) | |||||
| Chronic kidney disease etiology, n (%) |
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Chronic glomerulonephritis | 2823 (52.76) | 3015 (51.73) | 2445 (55.25) | 2064 (55.35) | ||||
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Diabetic nephropathy | 1120 (20.93) | 1191 (20.44) | 895 (20.23) | 818 (21.94) | ||||
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Hypertensive nephropathy | 262 (4.90) | 557 (9.56) | 218 (4.93) | 370 (9.92) | ||||
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Lupus nephritis | 68 (1.27) | 50 (0.86) | 57 (1.29) | 29 (0.78) | ||||
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ANCA-associatedb vasculitis | 57 (1.07) | 64 (1.10) | 53 (1.20) | 33 (0.88) | ||||
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Gouty nephropathy | 32 (0.60) | 125 (2.14) | 26 (0.59) | 72 (1.93) | ||||
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Polycystic kidney disease | 286 (5.34) | 214 (3.67) | 220 (4.97) | 150 (4.02) | ||||
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Other | 703 (13.14) | 612 (11.07) | 511 (11.54) | 204 (5) | ||||
| Comorbid conditions, n (%) |
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Cirrhosis | 86 (1.61) | 90 (1.54) | 81 (1.83) | 60 (1.61) | ||||
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Multiple myeloma | 46 (0.86) | 90 (1.54) | 46 (1.04) | 51 (1.37) | ||||
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Atrial fibrillation | 108 (2.02) | 109 (1.87) | 85 (1.92) | 72 (1.93) | ||||
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Congestive heart failure | 969 (18.11) | 999 (17.14) | 794 (17.94) | 605 (16.22) | ||||
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Ischemic heart disease | 1476 (27.58) | 1578 (27.08) | 1206 (27.25) | 983 (26.36) | ||||
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Metastatic cancer | 86 (1.61) | 91 (1.56) | 74 (1.67) | 38 (1.02) | ||||
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Lymphoma | 7 (0.13) | 7 (0.12) | 6 (0.14) | 1 (0.03) | ||||
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Chronic obstructive pulmonary disease | 241 (4.50) | 165 (2.83) | 169 (3.82) | 78 (2.09) | ||||
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Cerebrovascular disease | 322 (6.02) | 411 (7.05) | 244 (5.51) | 271 (7.27) | ||||
| Laboratory data |
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Leukocyte (109/L), mean (SD) | 7.32 (2.95) | 7.71 (3.79) | 7.40 (3.09) | 6.90 (3.22) | ||||
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Neutrophil (109/L), mean (SD) | 5.23 (2.68) | 5.06 (3.32) | 5.36 (2.78) | 4.22 (2.57 | ||||
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Hemoglobin (g/L), mean (SD) | 94.82 (23.30) | 83.09 (19.12) | 91.05 (21.68) | 86.50 (14.67) | ||||
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Platelet (109/L), mean (SD) | 193.28 (93.47) | 182.47 (83.70) | 190.84 (88.13) | 184.36 (71.39) | ||||
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Albumin (g/L), mean (SD) | 36.01 (6.75) | 33.27 (5.99) | 36.80 (6.59) | 33.98 (5.54) | ||||
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Phosphorus (mmol/L), mean (SD) | 1.81 (0.62) | 1.70 (0.66) | 1.66 (0.52) | 1.54 (0.50) | ||||
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Calcium (mmol/L), mean (SD) | 2.15 (0.28) | 2.02 (0.30) | 2.14 (0.22) | 2.08 (0.23) | ||||
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Potassium (mmol/L) | 4.87 (1.11) | 4.52 (0.91) | 4.76 (0.96) | 4.42 (0.69) | ||||
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Parathyroid hormone (pg/ml), mean (SD) | 334.71 (292.07) | 246.95 (193.61) | 315.98 (291.84) | 241.26 (206.48) | ||||
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Creatinine (μmol/L), mean (SD) | 807.11 (352.04) | 718.84 (336.47) | 755.28 (315.95) | 661.5 (268.48) | ||||
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Urea nitrogen (mmol/L), mean (SD) | 22.65 (12.07) | 23.61 (11.77) | 19.87 (8.72) | 20.01 (8.13) | ||||
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Uric acid (μmol/L), mean (SD) | 436.84 (147.54) | 450.27 (157.44) | 392.87 (126.48) | 402.19 (113.46) | ||||
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C-reactive protein, mean (SD) | 40.84 (44.09) | 25.65 (44.46) | 18.52 (35.01) | 20.23 (31.22) | ||||
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Cholesterol (mmol/L), mean (SD) | 4.34 (1.30) | 4.30 (1.42) | 4.27 (1.23) | 4.34 (1.25) | ||||
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Triglycerides (mmol/L), mean (SD) | 1.56 (1.00) | 1.60 (1.03) | 1.58 (0.96) | 1.63 (0.97) | ||||
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High-density lipoprotein, (mmol/L), mean (SD) | 1.14 (0.42) | 1.11 (0.43) | 1.12 (0.39) | 1.15 (0.38) | ||||
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Low-density lipoprotein (mmol/L), mean (SD) | 2.36 (1.10) | 2.37 (1.02 | 2.31 (1.04) | 2.35 (0.92) | ||||
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Very low-density lipoprotein (mmol/L), mean (SD) | 1.65 (1.55) | 2.11 (1.35) | 1.63 (1.54) | 1.60 (0.93) | ||||
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Ferritin (ng/mL), mean (SD)c | 174.59 (126.34) | 328.25 (295.78) | 144.34 (144.87) | 305.42 (278.73) | ||||
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eGFRd (mL/min/1.73m2), mean (SD) | 6.75 (3.79) | 7.28 (3.93) | 7.23 (3.85) | 7.58 (3.44) | ||||
| Vascular access at dialysis initiation, n (%) |
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Nontunneled catheter | 3295 (61.58) | 3388 (58.13) | 2495 (56.38) | 1893 (50.76) | ||||
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Tunneled catheter | 1068 (19.96) | 1266 (21.72) | 1005 (22.71) | 938 (25.15) | ||||
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Fistula or graft | 988 (18.46) | 1174 (20.14) | 925 (20.90) | 898 (24.08) | ||||
| Death at 1-year follow-up, n (%) | 585 (10.93) | 764 (13.11) | 437 (9.88) | 477 (12.79) | |||||
aThe missing rates of body mass index in the 4 cohorts were 270 (5.04%), 298 (5.11%), 210 (4.74%), and 168 (4.50%), respectively.
bANCA: antineutrophil cytoplasmic antibody.
cThe missing rates of ferritin in the 4 cohorts were 0.36%, 3.00%, 0.36%, and 2.13%, respectively.
deGFR: estimated glomerular filtration rate.