Table 1.
Characteristics of study sample
| ALL | Survivor | Nonsurvivor | p-value | Available data | |
|---|---|---|---|---|---|
| N = 491 | N = 347 | N = 144 | |||
| Sociodemographic characteristics | |||||
| Age (years), median [P25; P75] | 65.0 [56.0;73.0] | 62.0 [53.0;70.0] | 71.5 [62.8;76.0] | < 0.001 | 491 |
| Female, n (%) | 155 (31.6%) | 107 (30.9%) | 48 (33.3%) | 0.678 | 490 |
| Body mass index (kg/cm2), median [P25; P75] | 29.0 [26.1;32.7] | 29.0 [26.1;33.5] | 28.8 [26.0;31.1] | 0.156 | 410 |
| Smoking history, n (%) | 0.676 | 472 | |||
| Former | 145 (30.7%) | 100 (30.0%) | 45 (32.4%) | ||
| Nonsmoker | 289 (61.2%) | 204 (61.3%) | 85 (61.2%) | ||
| Current | 38 (8.05%) | 29 (8.71%) | 9 (6.47%) | ||
| Comorbidities | |||||
| Hypertension, n (%) | 275 (56.0%) | 179 (51.6%) | 96 (66.7%) | 0.003 | 491 |
| Diabetes Mellitus, n (%) | 137 (27.9%) | 83 (23.9%) | 54 (37.5%) | 0.003 | 491 |
| Obesity, n (%) | 184 (37.5%) | 146 (42.1%) | 38 (26.4%) | 0.002 | 491 |
| Chronic cardiovascular disease, n (%) | 66 (13.5%) | 43 (12.4%) | 23 (16.0%) | 0.367 | 490 |
| Chronic pulmonary disease, n (%) | 59 (12.0%) | 37 (10.7%) | 22 (15.3%) | 0.201 | 491 |
| Chronic kidney disease, n (%) | 40 (8.16%) | 23 (6.63%) | 17 (11.9%) | 0.080 | 490 |
| Disease chronology | |||||
| Time since first symptoms to ICU admission (days), median [P25; P75] | 9.00 [7.00;12.0] | 9.00 [7.00;12.0] | 8.00 [6.00;11.2] | 0.167 | 491 |
| Time since hospital admission to ICU admission (days), median [P25; P75] | 2.00 [0.00;4.00] | 2.00 [0.00;3.00] | 2.00 [0.00;4.25] | 0.449 | 491 |
| Hospital stay (days), median [P25; P75] | 25.0 [15.0;41.5] | 27.0 [16.0;45.5] | 22.0 [14.8;32.2] | 0.029 | 491 |
| ICU stay (days), median [P25; P75] | 14.0 [7.00;27.5] | 12.0 [6.00;27.0] | 19.0 [11.8;28.0] | < 0.001 | 491 |
| Blood gases and laboratory parameters at ICU admission | |||||
| Oxygen saturation (%), median [P25; P75] | 94.0 [90.0;97.0] | 94.8 [91.5;97.0] | 92.3 [87.0;96.0] | < 0.001 | 483 |
| PaCO2 (mmHg), median [P25; P75] | 38.7 [33.2;45.0] | 37.0 [33.0;45.0] | 41.0 [34.3;50.6] | 0.002 | 464 |
| pH, median [P25; P75] | 7.41 [7.35;7.45] | 7.43 [7.37;7.46] | 7.38 [7.28;7.44] | < 0.001 | 465 |
| PaO2/FiO2, median [P25; P75] | 107 [76.0;148] | 109 [81.8;153] | 100 [65.6;136] | 0.008 | 449 |
| Glucose (mg/dL), median [P25; P75] | 159 [129;207] | 154 [126;197] | 174 [135;255] | 0.001 | 486 |
| Creatinine (mg/dL), median [P25; P75] | 0.84 [0.70;1.15] | 0.82 [0.69;1.04] | 0.90 [0.70;1.40] | 0.035 | 487 |
| C-reactive protein (mg/L), median [P25; P75] | 121 [57.0;216] | 114 [56.8;199] | 150 [59.4;234] | 0.147 | 472 |
| D-dimer (ng/mL), median [P25; P75] | 1023 [562;1898] | 836 [484;1536] | 1578 [976;3822] | < 0.001 | 451 |
| Leukocyte count (x109/L), median [P25; P75] | 9.90 [7.20;13.8] | 9.49 [6.95;13.0] | 11.7 [8.06;15.8] | < 0.001 | 487 |
| Neutrophil count (x109/L), median [P25; P75] | 8.90 [6.17;12.5] | 8.30 [5.80;11.4] | 10.6 [7.30;14.8] | < 0.001 | 468 |
| Lymphocyte count (x109/L), median [P25; P75] | 0.63 [0.41;0.88] | 0.68 [0.50;0.90] | 0.54 [0.35;0.80] | < 0.001 | 477 |
| Monocyte count (x109/L), median [P25; P75] | 0.40 [0.23;0.56] | 0.40 [0.25;0.56] | 0.34 [0.20;0.58] | 0.179 | 465 |
| Platelet count (x109/L), median [P25; P75] | 236 [185;307] | 237 [190;304] | 230 [165;317] | 0.131 | 485 |
| AST (U/L), median [P25; P75] | 42.6 [29.0;68.0] | 42.0 [29.0;68.0] | 42.8 [29.0;68.3] | 0.840 | 419 |
| ALT (U/L), median [P25; P75] | 41.0 [25.0;67.0] | 42.5 [27.0;67.8] | 35.5 [21.2;63.0] | 0.019 | 448 |
| Urea (mg/dL), median [P25; P75] | 52.0 [38.0;73.0] | 49.0 [35.0;68.0] | 62.2 [46.2;94.0] | < 0.001 | 445 |
| Severity scores at ICU admission | |||||
| APACHE-II score, median [P25; P75] | 12.0 [9.00;17.0] | 11.0 [8.00;15.0] | 15.0 [12.0;21.2] | < 0.001 | 356 |
| SOFA Score, median [P25; P75] | 5.00 [4.00;7.25] | 5.00 [4.00;7.00] | 7.00 [4.00;8.75] | < 0.001 | 380 |
| Interventions during ICU stay | |||||
| Antibiotics, n (%) | 461 (94.1%) | 321 (92.5%) | 140 (97.9%) | 0.037 | 490 |
| Hydroxychloroquine, n (%) | 32 (6.54%) | 26 (7.49%) | 6 (4.23%) | 0.261 | 489 |
| Tocilizumab, n (%) | 125 (25.6%) | 92 (26.5%) | 33 (23.2%) | 0.523 | 489 |
| Corticoids, n (%) | 483 (98.8%) | 341 (98.6%) | 142 (99.3%) | 0.676 | 489 |
| High flow oxygen nasal cannula, n (%) | 347 (80.5%) | 265 (84.9%) | 82 (68.9%) | < 0.001 | 431 |
| Noninvasive positive pressure ventilation, n (%) | 144 (29.9%) | 96 (28.2%) | 48 (34.3%) | 0.221 | 481 |
| Invasive mechanical ventilation, n (%) | 384 (78.4%) | 247 (71.4%) | 137 (95.1%) | < 0.001 | 490 |
| Prone positioning, n (%) | 277 (56.5%) | 161 (46.4%) | 116 (81.1%) | < 0.001 | 490 |
ALT: alanine aminotransferase; AST: aspartate aminotransferase; FiO2: fraction of inspired oxygen; ICU: Intensive care unit; PaCO2: carbon dioxide partial pressure; PaO2: oxygen partial pressure