The basic characteristics of the study cohort
| Patient demographics and clinical features | Number of missing values (proportion (%)) | Median (IQR) or number of non-null values (proportion (%)) |
| Age | 0 (0) | 70.00 (58.14–79.48) |
| Gender (male) | 0 (0) | 649 (49.35) |
| Comorbidities (diagnosed with diabetes mellitus, chronic ischaemic heart disease or chronic kidney disease) | 0 (0) | 482 (36.65) |
| Anion gap | 2 (0.15) | 15.00 (13.00–18.00) |
| Albumin | 305 (23.2) | 2.70 (2.30–3.20) |
| Bicarbonate | 2 (0.15) | 23.00 (20.00–27.00) |
| Bilirubin | 256 (19.47) | 0.50 (0.30–0.95) |
| Creatinine | 2 (0.15) | 1.30 (0.80–2.40) |
| Chloride | 2 (0.15) | 103.00 (99.00–107.00) |
| Glucose | 2 (0.15) | 128.00 (101.00–165.00) |
| Haematocrit | 2 (0.15) | 32.00 (28.40–36.00) |
| Haemoglobin | 2 (0.15) | 10.50 (9.30–11.90) |
| Lactate | 217 (16.50) | 1.80 (1.30–2.80) |
| Platelet | 2 (0.15) | 243.00 (164.00–365.00) |
| Potassium | 2 (0.15) | 4.20 (3.70–4.70) |
| Partial thromboplastin time (PTT) | 39 (2.97) | 31.40 (27.00–38.20) |
| International normalised ratio (INR) | 35 (2.66) | 1.30 (1.20–1.70) |
| Prothrombin time (PT) | 35 (2.66) | 14.70 (13.40–17.90) |
| Sodium | 2 (0.15) | 138.00 (135.00–141.00) |
| Blood urea nitrogen (BUN) | 2 (0.15) | 27.00 (17.00–46.00) |
| White blood cells (WBCs) | 2 (0.15) | 12.90 (8.60–19.60) |
| Calcium | 35 (2.66) | 8.30 (7.70–8.90) |
| Free calcium | 734 (55.82) | 1.10 (1.02–1.17) |
| Heart rate | 13 (0.99) | 95.00 (81.00–110.00) |
| Respiratory rate | 13 (0.99) | 20.00 (16.00–24.00) |
| Oxygen saturation (SpO2) | 14 (1.06) | 98.00 (95.00–100.00) |
| Temperature (°C) | 16 (1.22) | 36.67 (36.06–37.33) |
| Systolic blood pressure | 13 (0.99) | 118.00 (103.00–138.00) |
| Diastolic blood pressure | 13 (0.99) | 60.00 (51.00–72.00) |
| Mean arterial pressure | 13 (0.99) | 77.00 (66.08–89.58) |