Table 1.
Baseline characteristics and risk factors in derivation and validation cohorts
| Characteristics | Missing value, n | All patients (n = 662) | Derivation cohort (n = 510) | Validation cohort (n = 152) | P value |
|---|---|---|---|---|---|
| General characteristics | |||||
| Age (years) | 0 (0%) | 67 (56–78) | 67 (56–78) | 68 (56–78) | 0.558a |
| Men | 0 (0%) | 405 (61.2%) | 319 (62.5%) | 86 (56.6%) | 0.218b |
| BMI (kg/m2) | 1 (0.2%) | 24 (21–27) | 24 (21–27) | 24 (21–27) | 0.808a |
| Comorbidities | |||||
| ESRD | 0 (0%) | 37 (5.6%) | 27 (5.3%) | 10 (6.6%) | 0.686b |
| Diabetes | 0 (0%) | 202 (30.5%) | 154 (30.2%) | 48 (31.6%) | 0.822b |
| Cerebrovascular disease | 0 (0%) | 90 (13.6%) | 76 (14.9%) | 14 (9.2%) | 0.096b |
| Liver disease | 0 (0%) | 35 (5.3%) | 26 (5.1%) | 9 (5.9%) | 0.848b |
| Metastasis | 0 (0%) | 48 (7.3%) | 34 (6.7%) | 11 (9.2%) | 0.377b |
| Indication of ICU admission | |||||
| Sepsis | 1 (0.2%) | 117 (17.7%) | 87 (17.1%) | 30 (19.7%) | 0.523b |
| Postoperation | 1 (0.2%) | 330 (49.8%) | 246 (48.2%) | 84 (55.3%) | 0.153b |
| Respiratory | 1 (0.2%) | 54 (8.2%) | 39 (7.6%) | 15 (9.9%) | 0.478b |
| Cardiovascular | 1 (0.2%) | 33 (5.0%) | 28 (5.5%) | 5 (3.3%) | 0.378b |
| Neurological | 1 (0.2%) | 63 (9.5%) | 58 (11.3%) | 5 (3.3%) | 0.005b |
| Enrollment season | < 0.001b | ||||
| Spring (March to May) | 0 (0%) | 166 (25.1%) | 146 (28.6%) | 20 (13.2%) | |
| Summer (June to August) | 0 (0%) | 181 (27.3%) | 136 (26.7%) | 45 (29.6%) | |
| Fall (September to November) | 0 (0%) | 151 (22.8%) | 104 (20.4%) | 47 (30.9%) | |
| Winter (December to February) | 0 (0%) | 164 (24.8%) | 124 (24.3%) | 40 (26.3%) | |
| Vital signs | |||||
| MAP (mmHg) | 0 (0%) | 88 (78–97) | 88 (79–97) | 87 (76–96) | 0.305c |
| Heart rate (/min) | 0 (0%) | 88 (76–100) | 87 (76–100) | 89 (77–101) | 0.300a |
| Laboratory finding | |||||
| Lactate (mmol/L) | 133 (20.1%) | 1.9 (1.2–7.5) | 1.9 (1.2–7.6) | 1.8 (1.3–6.0) | 0.603a |
| Albumin (g/dL) | 107 (16.2%) | 3.1 (2.7–3.5) | 3.1 (2.7–3.5) | 3.0 (2.7–3.5) | 0.242a |
| WBC (k/μL) | 0 (0%) | 10.6 (8.1–14.3) | 10.6 (8.1–14.1) | 11.1 (8.2–14.7) | 0.585a |
| Hemoglobin (g/dL) | 0 (0%) | 10.2 (9.1–11.5) | 10.2 (9.1–11.6) | 9.9 (8.9–11.2) | 0.077a |
| Platelet (k/μL) | 0 (0%) | 178 (122–252) | 184 (126–257) | 160 (120–227) | 0.075a |
| Sodium (mmol/L) | 0 (0%) | 138 (135–141) | 138 (135–141) | 137 (134–140) | 0.081a |
| Potassium (mmol/L) | 0 (0%) | 3.9 (3.5–4.2) | 3.9 (3.5–4.2) | 3.8 (3.4–4.1) | 0.140a |
| Total calcium (mmol/L) | 94 (14.2%) | 2.1 (2.0–2.2) | 2.1 (2.0–2.2) | 2.1 (2.0–2.2) | 0.007a |
| Creatinine (mg/dL) | 0 (0%) | 1.0 (0.7–1.7) | 1.0 (0.7–1.7) | 0.9 (0.7–1.7) | 0.874a |
| CRP (mg/L) | 276 (41.7%) | 6.9 (2.4–16.8) | 6.7 (2.1–15.9) | 11.7 (3.8–19.4) | 0.013a |
| Vitamin D (ng/mL) | 0 (0%) | 18.3 (13.7–23.9) | 18.7 (13.9–24.0) | 17.5 (12.5–23.6) | 0.232a |
| SVDD | 0 (0%) | 116 (17.5%) | 83 (16.3%) | 33 (21.7%) | 0.154b |
BMI body mass index, ESRD end stage renal disease, MAP mean arterial pressure, WBC white blood cell, CRP C-reactive protein, SVDD severe vitamin D deficiency
Data are presented as number (%), or median (interquartile range). Statistical methods: aMann–Whitney test; bChi-squared test; cStudent’s t test