Table 1 Patient baseline characteristics in derivation and validation cohorts
Variable | Derivation cohort (n = 105) | Validation cohort (n = 93) | p value |
|---|---|---|---|
Baseline characteristics | |||
 Age (years) | 65 (52, 73) | 64 (50, 67) | 0.763 |
 Female gender | 45 (42.8) | 36 (38.7) | 0.518 |
 BMI (kg/m2) | 22.7 (19.9, 24.5) | 23.9 (20.5, 26.1) | 0.812 |
 APACHE II score | 14.9 (13.8, 17.0) | 15.7 (14.0, 19.0) | 0.634 |
 SOFA score | 6 (4, 7) | 6 (5, 7.8) | 0.663 |
 Serum creatinine before surgery (μmol/L) | 63.2 (54.0, 69.8) | 66.5 (55.1, 73.4) | 0.719 |
 Hemoglobin (g/L) | 86.0 (77.5, 97.0) | 87.8 (78.4, 99.2) | 0.826 |
Surgery | |||
 Abdominal surgery | 72 (69.6) | 58 (62.3) | 0.497 |
 Contaminated surgery procedure | 70 (57.1) | 52 (55.9) | 0.672 |
 Duration (h) | 5.2 (2.2, 8.7) | 5.4 (2.5, 7.9) | 0.582 |
 Bleeding (ml) | 450 (200, 800) | 500 (250, 900) | 0.439 |
Major infection site | |||
 Intra-abdominal infection | 18 (17.1) | 14 (15.1) | 0.619 |
 Pulmonary infection | 5 (4.7) | 8 (8.6) | 0.524 |
 Bloodstream infection | 9 (8.6) | 5 (5.4) | 0.587 |
 Urinary tract infection | 8 (7.6) | 9 (5.4) | 0.496 |
 Others | 6 (5.7) | 7 (7.5) | 0.703 |
Serum creatinine diagnosing AKI (μmol/L) | 137.4 (118.3, 158.4) | 142.6 (112.5, 164.7) | 0.413 |
UO 24Â h after ICU admission (ml/kg/h) | 1.0 (0.5, 1.5) | 1.1 (0.7, 1.8) | 0.576 |
UO 48Â h after ICU admission (ml/kg/h) | 0.8 (0.4, 1.9) | 0.9 (0.4, 1.5) | 0.618 |
AKI classification | |||
 Stage 1 | 42 (40.0) | 36 (38.7) | 0.672 |
 Stage 2 | 44 (41.9) | 41 (44.0) | 0.754 |
 Stage 3 | 19 (18.1) | 16 (17.3) | 0.812 |
Outcome | |||
 Renal recovery in 7 days | 64 (60.9) | 58 (62.3) | 0.645 |
 Renal recovery at hospital discharge | 69 (65.7) | 62 (66.6) | 0.783 |
 Need for RRT in 7 days | 19 (18.1) | 18 (19.3) | 0.796 |
 Hospital mortality | 9 (9.2) | 8 (8.6) | 0.510 |
 28-day mortality | 14 (13.3) | 12 (12.9) | 0.694 |