Table 1.
Characteristics of 2017 critically ill patients included in machine learning analysis according to overall or cluster (phenotype) population.
| Variable | Overall n = 2017 |
A phenotype n = 537 |
B phenotype n = 623 |
C phenotype n = 857 |
|---|---|---|---|---|
| General characteristics and severity of illness | ||||
| Age, median (p25–75), years | 64 (55–71) | 63 (53–70) | 63 (53.5–71.5) | 66 (58–72)*** |
| Male, n (%) | 1419 (70.3) | 377 (70.2) | 416 (66.8) | 626 (73.0)* |
| APACHE II, median (p25–75), | 13 (10–17) | 12 (9–16) | 13 (10–16) | 17 (14–22)*** |
| SOFA, median (p25–75), | 5 (3.7) | 4 (3–5) | 5 (3–7) | 7 (6–8)*** |
| GAP diagnosis, median (p25–75) | 6.2 (4.0–8.0) | 7.0 (4.0–9.0) | 6.0 (4.0–8.0)* | 6.0 (4.3–8.0)* |
| GAP UCI, median (p25–75) | 2.0 (0.0–4.0) | 2.0 (1.0–4.0) | 2.0 (1.0–4.0) | 1.1 (0.0–3.0)** |
| Laboratory findings | ||||
| d-Lactate dehydrogenase, median (p25–75), U/L | 537 (417–707) | 474 (372–564) | 477 (378–570) | 670 (554–929)*** |
| White blood cell, median (p25–75), ×109 | 8.8 (6.2–12.2) | 7.7 (5.8–10.2) | 8.5 (6–11.7) | 10 (6.9–13.6)*** |
| Serum creatinine, median (p25–75), mg/dL | 0.88 (0.7–1.1) | 0.80 (0.66–1.01) | 0.80 (0.66–1.00) | 0.99 (0.76–1.36)*** |
| C-reactive protein, median (p25–75), mg/mL | 15.5 (9.1–24.3) | 14 (8–2) | 14 (9–22) | 18 (10–26)*** |
| Procalcitonin, median (p25–75), ng/mL | 0.3 (0.1–2.0) | 0.2 (0.1–0.6) | 0.2 (0.1–0.5) | 0.5 (0.2–1.3)*** |
| Serum lactate, median (p25–75), mmol/L | 1.5 (1.1–2.0) | 1.5 (1.1–1.9) | 1.4 (1.0–1.9) | 1.6 (1.2–2.2)*** |
| D dimer, median (p25–75), ng/mL | 1593 (720–3790) | 1090 (580–2100) | 1319 (634–3548) | 2260 (1009–4894)*** |
| Ferritin, median (p25–75), ng/mL | 1600 (1290–2240) | 1538 (1280–1899) | 1554 (1271–1936) | 1800 (1416–2377)*** |
| Coexisting condition and comorbidities | ||||
| Arterial hypertension, n (%) | 932 (46.2) | 211 (39.3) | 173 (27.8) | 548 (63.9)*** |
| Obesity (BMI > 30), n (%) | 653 (32.3) | 159 (29.6) | 200 (32.1) | 294 (34.3) |
| Diabetes, n (%) | 418 (20.7) | 112 (20.9) | 108 (17.3) | 198 (23.1)* |
| Coronary arterial disease, n (%) | 124 (6.1) | 35 (6.5) | 41 (6.6) | 48 (5.6) |
| COPD, n (%) | 148 (7.3) | 37 (6.9) | 38 (6.1) | 73 (8.5) |
| Chronic renal disease, n (%) | 85 (4.2) | 31 (5.8) | 10 (1.6) | 44 (5.1)*** |
| Hematologic disease, n (%) | 72 (3.5) | 20 (3.7) | 22 (3.5) | 30 (3.5) |
| Asthma, n (%) | 120 (5.9) | 41 (7.6) | 45 (7.2) | 34 (4.0)** |
| HIV, n (%) | 5 (0.2) | 2 (0.4) | 1 (0.2) | 2 (0.2) |
| Pregnancy, n (%) | 4 (0.19) | 1 (0.2) | 3 (0.5) | 0 (0.0) |
| Autoimmune disease, n (%) | 74 (3.6) | 20 (3.7) | 18 (2.9) | 36 (4.2) |
| Chronic heart disease, n (%) | 57 (2.8) | 21 (3.9) | 10 (1.6) | 26 (3.0) |
| Neuromuscular disease, n (%) | 16 (0.8) | 3 (0.6) | 5 (0.8) | 8 (0.9) |
| Oxygenation and ventilator support | ||||
| Oxygen mask, n (%) | 325 (16.1) | 124 (23.1) | 105 (16.9)** | 96 (11.2)*** |
| High flow nasal cannula, n (%) | 375 (18.6) | 345 (64.2) | 3 (0.5)*** | 27 (3.2)*** |
| Non-invasive ventilation, n (%) | 140 (6.9) | 64 (11.9) | 26 (4.2)*** | 50 (5.8)*** |
| Invasive mechanical ventilation, n (%) | 1172 (58.1) | 3 (0.6) | 475 (76.2)*** | 694 (81.0)*** |
| PaO2/FiO2, median (p25–75) | 132 (96–163) | 111 (82–133) | 165 (144–212)*** | 126 (88–155)*** |
| Complications and outcome | ||||
| Shock, n (%) | 904 (44.8) | 56 (10.4) | 196 (31.5) | 652 (76.1) |
| Acute kidney dysfunction, n (%) | 579 (28.7) | 111 (20.7) | 118 (18.9) | 350 (40.8)*** |
| Myocardial dysfunction, n (%) | 169 (8.3) | 30 (5.6) | 43 (6.9) | 96 (11.2)*** |
| >2 quadrant infiltrates in chest X-ray, n (%) | 1327 (65.7) | 341 (63.5) | 413 (66.3) | 573 (66.8) |
| ICU crude mortality, n (%) | 657 (32.6) | 109 (20.3) | 159 (25.5)* | 389 (45.4)*** |
Abbreviations: p25–27, percentile range; APACHE II, Acute Physiology and Chronic Health Evaluation II; SOFA, Sequential Organ Failure Assessment; BMI, body mass index; COPD, chronic obstructive pulmonary disease; HIV, human immunodeficiency viruses; PaO2/FiO2, partial pressure arterial oxygen/fraction of inspired oxygen.
All comparisons were made with respect to phenotype A considered as the reference.
*
p < .05.
**
p < .01.
***
p < .001, others comparison p > .01.