Table 2.
Baseline characteristics of the undersampled training cohort and the testing cohort
| Characteristic mean (SD) or N (%) | Training (n = 2873) | Testing (n = 719) | P value |
|---|---|---|---|
| Age, years | 70 (57–83) | 71 (57–83) | 0.839 |
| Male | 1838 (63.97) | 455 (63.28) | 0.730 |
| BMI, kg/m2 | 23 (20–26) | 24 (21–26) | 0.060 |
| Smoking | 759 (26.42) | 184 (25.59) | 0.652 |
| Drinking | 688 (23.95) | 157 (21.84) | 0.233 |
| Complications | |||
| Hypertension | 1268 (44.14) | 333 (46.31) | 0.293 |
| Diabetes | 677 (23.56) | 166 (23.09) | 0.787 |
| Laboratory results | |||
| d-Dimer, ug/ml | 2.22 (0.83–4.85) | 2.3 (0.81–4.6) | 0.635 |
| Sodium, mmol/l | 140.9 (137.1–144.6) | 141.1 (137.8–145.1) | 0.601 |
| White blood cell count, 109/l | 8.91 (5.95–14.01) | 8.81 (5.96–13.25) | 0.286 |
| Direct bilirubin, umol/l | 5.8 (3.1–14.6) | 5.9 (3.1–14.7) | 0.011 |
| PT, s | 15.2 (13.7–18.7) | 15.4 (13.8–19.5) | 0.348 |
| PTA, % | 74 (52–90) | 72 (49–90) | 0.203 |
| TT, s | 16.2 (15.2–17.8) | 16.2 (15–18.1) | 0.441 |
| Phosphorous, mmol/l | 1.1 (0.86–1.38) | 1.13 (0.88–1.47) | 0.059 |
| Creatinine, umol/l | 88.2 (64.35–163.2) | 86.4 (63. 4–155.6) | 0.187 |
| Lumbar disc herniation, U/l | 259.5 (173.1–483.8) | 281 (176.6–520.55) | 0.552 |
| Alanine aminotransferase, U/l | 18.2 (10.6–40.9) | 19.75 (10.38–40.65) | 0.203 |
| Potassium, mmol/l | 4.04 (3.71–4.51) | 4.04 (3.71–4.52) | 0.886 |
| NT-proBNP, pg/ml | 1762 (379.7–6683.25) | 1732 (284.82–7611.5) | 0.637 |
| Magnesium, mmol/l | 0.86 (0.77–0.95) | 0.87 (0.79–0.96) | 0.109 |
| Glucose, mmol/l | 7.24 (5.36–10.09) | 7.18 (5.35–10.41) | 0.652 |
| Platelets, 109/l | 160 (85–226) | 160 (78–225) | 0.371 |
| Amylase, U/l | 60.3 (38.4–106.4) | 62.6 (38.28–110.5) | 0.414 |
| Hemoglobin, g/l | 102 (82–126) | 100 (80–125) | 0.835 |
| Calcium, mmol/l | 2.11 (1.96–2.24) | 2.12 (1.95–2.23) | 0.496 |
| APTT, s | 40.8 (36.1–50.3) | 41.1 (35.5–52.28) | 0.326 |
| Hematocrit, L/l | 0.31 (0.25–0.37) | 0.31 (0.24–0.37) | 0.436 |
| Fibrinogen, g/l | 3.35 (2.47–4.46) | 3.4 (2.51–4.42) | 0.807 |
| Neutrophils | 0.83 (0.68–0.9) | 0.83 (0.69–0.9) | 0.640 |
| Total protein, g/l | 61 (53.9–67) | 61.1 (53.6- 67.5) | 0.820 |
| Troponin T, ng/ml) | 0.06 (0.02–0.23) | 0.08 (0.02–0.23) | 0.479 |
| Serum uric acid, umol/l | 327.7 (235.25–467.75) | 331.7 (234.65–458.1) | 0.911 |
| Chloride, mmol/l | 102.9 (98.8–106.8) | 103.2 (99.1–107.1) | 0.940 |
| Serum albumin, g/l | 33.7 (29.2–38.3) | 34.2 (29.02–38.7) | 0.633 |
| Aspartate aminotransferase, U/l | 27 (16–74.9) | 28.1 (16.2–73.7) | 0.264 |
| CRP, mg/dl | 3.94 (0.88–9.8) | 4.75 (0.84–10.09) | 0.277 |
BMI Body Mass Index, PT prothrombin time, PTA prothrombin activity, TT thrombin time, NT-proBNP N-terminal pro-BNP, APTT activated partial thromboplastin time, CRP C-reactive protein