Table 1. Patient characteristics by referral pattern.a .
| Total ESRD | DM ESRD | ||||||||||
| Total (N = 1028) | Early referral (N = 599) | Late referral (N = 429) | P Value | Total (N = 511) | Early referral (N = 302) | Late referral (N = 209) | P Value | ||||
| Age at the time of dialysis (year) | 57.0±13.9 | 57.4±13.5 | 56.5±14.4 | 0.329 | 59.1±11.5 | 59.9±11.4 | 57.8±11.5 | 0.044 | |||
| Gender (male, %) | 59.6 | 58.3 | 61.5 | 0.303 | 63.0 | 60.6 | 66.5 | 0.174 | |||
| Length of follow-up (mo) | 10.2±6.9 | 10.7±7.1 | 9.4±6.6 | 0.003 | 10.1±6.8 | 10.8±7.3 | 9.1±5.9 | 0.004 | |||
| Drop out (N, %) | 95 (9.2) | 49 (8.2) | 46 (10.7) | 0.190 | 46 (9.0) | 24 (7.9) | 22 (10.5) | 0.347 | |||
| Findings at the time of referral to nephrologist | |||||||||||
| Underlying kidney disease (%) | 0.181 | ||||||||||
| Diabetes mellitus | 49.7 | 50.4 | 48.7 | ||||||||
| Hypertension | 17.5 | 15.5 | 20.3 | ||||||||
| Glomerulonephritis | 15.3 | 18.0 | 11.4 | ||||||||
| Polycystic kidney disease | 2.0 | 2.8 | 0.9 | ||||||||
| Others | 7.8 | 8.0 | 7.5 | ||||||||
| Unknown | 7.7 | 5.2 | 11.2 | ||||||||
| Systolic BP (mmHg) | 147.1±27.6 | 143.3±26.8 | 151.0±28.0 | <0.001 | 146.0±26.2 | 143.8±26.2 | 148.7±26.0 | 0.086 | |||
| Diastolic BP (mmHg) | 84.7±16.5 | 83.4±16.0 | 86.1±16.9 | 0.032 | 81.3±14.8 | 80.5±15.1 | 82.2±14.5 | 0.311 | |||
| Serum creatinine (mg/dL) | 4.8±4.1 | 2.6±1.5 | 7.2±4.6 | <0.001 | 4.1±3.0 | 2.6±1.4 | 6.0±3.4 | <0.001 | |||
| eGFR (mL/min/1.73m2) | 24.5±33.9 | 36.1±42.7 | 11.4±8.0 | <0.001 | 24.5±21.3 | 34.2±24.0 | 12.8±8.2 | <0.001 | |||
| Hemoglobin (g/dL) | 10.0±5.0 | 11.2±6.4 | 8.8±1.8 | <0.001 | 9.7±1.9 | 10.5±1.8 | 8.9±1.7 | <0.001 | |||
| Number of visits to nephrologist from referral to dialysis (%) | <0.001 | <0.001 | |||||||||
| None | 8.6 | 0 | 20.5 | 6.1 | 0 | 14.8 | |||||
| 1 time | 7.4 | 1.8 | 15.2 | 6.7 | 2.3 | 12.9 | |||||
| 2 times or more | 84.0 | 98.2 | 64.3 | 87.2 | 97.7 | 72.2 | |||||
| Time from referral to dialysis (month) | 37.7±53.8 | 62.3±58.9 | 2.9±3.4 | <0.001 | 29.1±37.0 | 46.8±39.1 | 3.3±3.5 | <0.001 | |||
| Findings at the time of dialysis | |||||||||||
| Modified Charlson co-morbidity index | 5.1±2.5 | 5.2±2.5 | 5.0±2.5 | 0.218 | 6.1±2.2 | 6.2±2.3 | 6.0±2.1 | 0.189 | |||
| Davies co-morbidity index | 1.0±0.9 | 1.0±0.9 | 1.0±1.0 | 0.919 | 1.5±0.8 | 1.5±0.8 | 1.6±0.8 | 0.656 | |||
| Serum creatinine (mg/dL) | 8.4±3.9 | 8.3±3.6 | 8.5±4.2 | 0.147 | 7.8±3.1 | 7.8±3.1 | 7.7±3.2 | 0.642 | |||
| eGFR (mL/min/1.73m2) | 7.6±3.4 | 7.5±3.2 | 7.7±3.7 | 0.288 | 8.1±3.4 | 7.9±3.2 | 8.4±3.6 | 0.115 | |||
| Hemoglobin (g/dL) | 9.0±3.5 | 8.9±1.6 | 8.8±1.7 | 0.468 | 9.1±3.8 | 8.9±1.5 | 8.9±1.6 | 0.854 | |||
| Transferrin saturation (%) | 33.3±51.8 | 33.0±46.2 | 33.8±58.6 | 0.825 | 32.4±62.3 | 30.9±44.6 | 34.5±81.2 | 0.553 | |||
| Hemoglobin A1c (%) | 6.9±2.5 | 6.9±1.7 | 6.6±1.3 | 0.039 | |||||||
| Uric acid (mg/dL) | 8.2±5.1 | 8.0±2.5 | 8.2±2.6 | 0.228 | 8.2±5.5 | 8.0±2.4 | 7.9±2.3 | 0.850 | |||
| Calcium (mg/dL) | 7.9±3.9 | 7.8±1.0 | 7.7±1.1 | 0.331 | 8.0±4.2 | 7.8±0.9 | 7.7±0.9 | 0.148 | |||
| Phosphate (mg/dL) | 5.5±3.0 | 5.3±1.8 | 5.6±2.0 | 0.042 | 5.5±2.8 | 5.3±1.7 | 5.5±1.8 | 0.437 | |||
| iPTH (pg/mL) | 256.0±239.9 | 267.2±258.0 | 240.0±210.9 | 0.105 | 219.0±189.5 | 218.1±174.8 | 220.4±210.4 | 0.905 | |||
| Systolic BP (mmHg) | 140.3±23.7 | 138.2±23.8 | 143.2±23.3 | 0.001 | 141.8±24.5 | 139.8±24.5 | 144.9±24.1 | 0.023 | |||
| Diastolic BP (mmHg) | 78.4±14.1 | 77.3±13.2 | 80.1±15.0 | 0.002 | 76.7±13.1 | 75.4±12.4 | 78.5±13.4 | 0.008 | |||
| BMI (kg/m2) | 23.3±6.3 | 23.1±3.3 | 23.6±8.9 | 0.211 | 23.5±3.4 | 23.6±3.3 | 23.4±3.6 | 0.625 | |||
| Total cholesterol (mg/dL) | 159.2±50.7 | 156.2±48.5 | 163.4±53.2 | 0.030 | 157.7±55.7 | 153.5±51.1 | 163.9±61.4 | 0.053 | |||
| Triglycerides (mg/dL) | 129.8±82.4 | 129.7±86.6 | 129.8±76.3 | 0.991 | 135.9±86.4 | 134.0±85.2 | 138.5±88.3 | 0.593 | |||
| LDL cholesterol (mg/dL) | 93.6±55.1 | 90.0±53.7 | 98.5±56.6 | 0.038 | 93.7±66.9 | 89.1±66.0 | 100.0±67.8 | 0.117 | |||
| HDL cholesterol (mg/dL) | 39.7±14.3 | 39.7±14.6 | 39.8±13.9 | 0.902 | 38.3±13.2 | 37.6±12.3 | 39.5±14.3 | 0.149 | |||
a
Values for continuous variables are means ± standard deviation; values for categorical variables expressed as proportion. BP, blood pressure; eGFR, estimated glomerular filtration rate; iPTH, intact parathyroid hormone; BMI, body mass index; LDL, low-density lipoprotein; HDL, high-density lipoprotein.