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 24 h after ICU admission (ml/kg/h) | 1.0 (0.5, 1.5) | 1.1 (0.7, 1.8) | 0.576 |
| UO 48 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 |
Values are median (25th, 75th percentile interquartile range) or n (%)
AKI acute kidney injury, APACHE II acute physiology and chronic health evaluation, BMI body mass index, ICU intensive care unit, RRT renal replacement therapy, SOFA sequential organ failure assessment, UO 24 h first 24-h urine output, UO 48 h first 48-h urine output