Table 1 Comparison of feature distributions between the training, internal validation, and external validation sets.
Variables | Training (n = 670) | Internal validation (n = 285) | External validation (n = 3170) | P-value |
|---|---|---|---|---|
Age (years), mean (SD) | 63.5 ± 17 | 62.7 ± 16.6 | 64 ± 17.3 | 0.425 |
Male, n (%) | 437 (65.2) | 191 (67) | 1882 (59.4) | 0.002 |
SOFA (score), mean (SD) | 7 ± 3.4 | 6.9 ± 3.5 | 5.1 ± 3 | < 0.001 |
RRT, n (%) | 52 (7.8) | 17 (6) | 100 (3.2) | < 0.001 |
Uo_6h (mL/kg/h), mean (SD) | 0.2 ± 0.3 | 0.2 ± 0.3 | 0.3 ± 0.3 | < 0.001 |
Uo_24h (mL/kg/h) | 1.15 (0.73, 1.66) | 1.25 (0.82, 1.85) | 0.63 (0.43, 0.92) | < 0.001 |
Comorbidities, n (%) | ||||
Hypertension | 303 (45.2) | 126 (44.2) | 1589 (50.1) | 0.018 |
Diabetes | 87 (13) | 38 (13.3) | 766 (24.2) | < 0.001 |
Biochemical indexes on ICU admission, mean (SD) | ||||
Creatinine (mmol/L) | 107.1 ± 60.5 | 103.4 ± 58.5 | 83 ± 41.9 | < 0.001 |
White blood cell (× 109/L) | 12.3 ± 6.4 | 12.8 ± 7 | 12.9 ± 6.1 | 0.072 |
pH | 7.4 ± 0.1 | 7.4 ± 0.1 | 7.4 ± 0.1 | 0.542 |
Bicarbonate (mmol/L) | 20.9 ± 3.8 | 20.7 ± 3.7 | 22.8 ± 3.7 | < 0.001 |
Lactate (mmol/L) | 3.4 ± 3.3 | 3.2 ± 3.1 | 2.7 ± 2 | < 0.001 |
Urea (mmol/L) | 9.2 ± 4.7 | 9.2 ± 4.5 | 18.3 ± 10.4 | < 0.001 |
Vital signs on first day ICU admission, mean (SD) | ||||
Maximum glucose (mmol/L) | 11.7 ± 5.1 | 11.5 ± 4.6 | 190.7 ± 65.7 | < 0.001 |
Mean systolic pressure (mmHg) | 125.3 ± 17 | 125.1 ± 16.7 | 117.8 ± 14.8 | < 0.001 |
Mean temperature (°C) | 37.2 ± 0.7 | 37.2 ± 0.7 | 37 ± 0.6 | < 0.001 |
Mean heart rate (bpm) | 89.5 ± 18.6 | 90.4 ± 19.8 | 87.9 ± 14.8 | 0.004 |
Outcome | ||||
Persistent AKI, n (%) | 264 (39.4) | 112 (39.3) | 1429 (45.1) | 0.008 |
ICU length of stay (days), median (IQR) | 2.19 (0.73, 8.5) | 1.86 (0.55, 7.82) | 4.37 (2.97, 8.91) | < 0.001 |
Hosp. LOS (days), median (IQR) | 22 (14, 33) | 21 (14, 32) | 11.08 (7.17, 17.88) | < 0.001 |
Hospital mortality, n (%) | 114 (17) | 57 (20) | 348 (11) | < 0.001 |
