Table 1.
Baseline characteristics of patients, stratified by the different advance ventilatory supports
| Characteristic | All n = 66,565 | HFNC n = 28,256 | NIV n = 24,112 | IMV n = 14,197 | p value |
|---|---|---|---|---|---|
| Demographics, n (%) | |||||
| Female | 24,309 (36.5) | 11,188 (39.6) | 8600 (35.7) | 4521 (31.8) | < 0.001 |
| Age 0–20 years old | 558 (0.9) | 188 (0.7) | 156 (0.6) | 214 (1.5) | < 0.001 |
| Age 20–40 years old | 4888 (7.4) | 1800 (6.3) | 1635 (6.8) | 1453 (10.2) | < 0.001 |
| Age 40–60 years old | 19,514 (29.3) | 6907 (24.5) | 7429 (30.8) | 5178 (36.5) | < 0.001 |
| Age 60–80 years old | 29,317 (44.0) | 11,350 (40.2) | 11,505 (47.7) | 6462 (45.5) | < 0.001 |
| Age 80–100 years old | 12,232 (18.4) | 7962 (28.1) | 3382 (14.1) | 888 (6.2) | < 0.001 |
| Age ≥ 100 years old | 56 (0.1) | 49 (0.2) | 5 (0.0) | 2 (0.0) | < 0.001 |
| Pandemic wave in which patients were admitted, n (%) | |||||
| First COVID-19 wave | 27,044 (40.6) | 13,363 (47.3) | 7888 (32.7) | 5793 (40.8) | < 0.001 |
| Continent of admission, n (%) | |||||
| Africa | 89 (0.1) | 17 (0.1) | 3 (0.0) | 69 (0.5) | < 0.001 |
| Asia | 10,488 (15.8) | 1520 (5.4) | 2590 (10.7) | 6378 (44.9) | < 0.001 |
| Europe | 52,039 (78.2) | 25,586 (90.6) | 20,924 (86.8) | 5529 (38.9) | < 0.001 |
| North America | 2434 (3.7) | 561 (2.0) | 277 (1.1) | 1596 (11.2) | < 0.001 |
| Oceania | 260 (0.4) | 155 (0.5) | 8 (0.0) | 97 (0.7) | < 0.001 |
| South America | 1255 (1.9) | 417 (1.5) | 310 (1.3) | 528 (3.7) | < 0.001 |
| Regional income stratification, n (%) | |||||
| High-income country | 55,004 (82.6) | 26,399 (93.4) | 21,237 (88.1) | 7368 (51.9) | < 0.001 |
| Low middle-income country | 11,561 (17.4) | 1857 (6.6) | 2875 (11.9) | 6829 (48.1) | < 0.001 |
| Chronic comorbidities, n (%) | |||||
| Asthma | 8097 (12.2) | 3596 (12.7) | 3413 (14.2) | 1088 (7.7) | < 0.001 |
| Chronic cardiac disease (not hypertension) | 14,678 (22.1) | 7794 (27.6) | 5153 (21.4) | 1731 (12.2) | < 0.001 |
| Chronic kidney disease | 7533 (11.3) | 4135 (14.6) | 2571 (10.7) | 827 (5.8) | < 0.001 |
| Chronic neurological disorder | 4944 (7.4) | 2808 (9.9) | 1560 (6.5) | 576 (4.1) | < 0.001 |
| Chronic pulmonary disease (not asthma) | 8856 (13.3) | 4459 (15.8) | 3551 (14.7) | 846 (6.0) | < 0.001 |
| Dementia | 3964 (6.0) | 3032 (10.7) | 818 (3.4) | 114 (0.8) | < 0.001 |
| Diabetes mellitus | 20,164 (30.3) | 8273 (29.3) | 7343 (30.5) | 4548 (32.0) | < 0.001 |
| HIV | 271 (0.4) | 105 (0.4) | 93 (0.4) | 73 (0.5) | 0.08 |
| Arterial hypertension | 27,521 (41.3) | 11,855 (42.0) | 9874 (41.0) | 5792 (40.8) | 0.02 |
| Hypothyroidism | 1632 (2.5) | 864 (3.1) | 598 (2.5) | 170 (1.2) | < 0.001 |
| Immunosuppression | 1242 (1.9) | 659 (2.3) | 491 (2.0) | 92 (0.6) | < 0.001 |
| Malignant neoplasm | 5115 (7.7) | 2811 (9.9) | 1803 (7.5) | 501 (3.5) | < 0.001 |
| Malnutrition | 894 (1.3) | 565 (2.0) | 229 (0.9) | 100 (0.7) | < 0.001 |
| Mental disorder | 1042 (1.6) | 541 (1.9) | 418 (1.7) | 83 (0.6) | < 0.001 |
| Moderate or severe liver disease | 880 (1.3) | 465 (1.6) | 282 (1.2) | 133 (0.9) | < 0.001 |
| Obesity | 10,793 (16.2) | 3960 (14.0) | 4883 (20.3) | 1950 (13.7) | < 0.001 |
| Rheumatological disorder | 5412 (8.1) | 3033 (10.7) | 1989 (8.2) | 390 (2.7) | < 0.001 |
| Smoking | 15,190 (22.8) | 6948 (24.6) | 6521 (27.0) | 1721 (12.1) | < 0.001 |
| Solid tumour | 522 (0.8) | 307 (1.1) | 186 (0.8) | 29 (0.2) | < 0.001 |
| Complications, n (%) | |||||
| Acute kidney injury | 13,353 (20.1) | 5146 (18.2) | 4525 (18.8) | 3682 (25.9) | < 0.001 |
| Anaemia | 10,031 (15.1) | 3803 (13.5) | 3492 (14.5) | 2736 (19.3) | < 0.001 |
| ARDS | 15,470 (23.2) | 4846 (17.2) | 5625 (23.3) | 4999 (35.2) | < 0.001 |
| Bacteraemia | 3966 (6.0) | 1191 (4.2) | 1381 (5.7) | 1394 (9.8) | < 0.001 |
| Cardiac arrest | 3882 (5.8) | 1215 (4.3) | 1275 (5.3) | 1392 (9.8) | < 0.001 |
| Cardiac arrhythmia | 5989 (9.0) | 2070 (7.3) | 2208 (9.2) | 1711 (12.1) | < 0.001 |
| Cardiac ischemia | 1175 (1.8) | 471 (1.7) | 426 (1.8) | 278 (2.0) | 0.10 |
| Coagulation disorder | 3231 (4.9) | 1122 (4.0) | 1346 (5.6) | 763 (5.4) | < 0.001 |
| Congestive heart failure | 2188 (3.3) | 1159 (4.1) | 749 (3.1) | 280 (2.0) | < 0.001 |
| Gastrointestinal bleeding | 1130 (1.7) | 519 (1.8) | 310 (1.3) | 301 (2.1) | < 0.001 |
| Liver dysfunction | 5600 (8.4) | 1972 (7.0) | 2176 (9.0) | 1452 (10.2) | < 0.001 |
| Neurological complication | 1206 (1.8) | 522 (1.8) | 458 (1.9) | 226 (1.6) | 0.08 |
| Pleural effusion | 3967 (6.0) | 1858 (6.6) | 1285 (5.3) | 824 (5.8) | < 0.001 |
| Pneumothorax | 1590 (2.4) | 458 (1.6) | 671 (2.8) | 461 (3.2) | < 0.001 |
| Pulmonary embolism | 1951 (2.9) | 667 (2.4) | 869 (3.6) | 415 (2.9) | < 0.001 |
| Stroke | 918 (1.4) | 358 (1.3) | 302 (1.3) | 258 (1.8) | < 0.001 |
| Treatments, n (%) | |||||
| Prone | 15,778 (23.7) | 3384 (12.0) | 6628 (27.5) | 5766 (40.6) | < 0.001 |
| Vasopressors/inotropes | 13,592 (20.4) | 2188 (7.7) | 4282 (17.8) | 7122 (50.2) | < 0.001 |
| Corticoids | 40,810 (61.3) | 15,586 (55.2) | 17,043 (70.7) | 8181 (57.6) | < 0.001 |
| Intensive care unit | 36,336 (54.6) | 8302 (29.4) | 14,180 (58.8) | 13,854 (97.6) | < 0.001 |
| Clinical outcomes | |||||
| Hospital discharge | 33,627 (50.5) | 16,302 (57.7) | 12,115 (50.2) | 5210 (36.7) | < 0.001 |
| 28-day fatality ratio | 24,021 (36.1) | 9581 (33.9) | 9177 (38.1) | 5263 (37.1) | < 0.001 |
| Non-invasive ventilation failure (HFNC and NIV) | 10,287 (15.5) | 3538 (12.5) | 6749 (28.0) | < 0.001 | |
Bold values indicate statistical significance
HFNC high-flow nasal cannula, NIV non-invasive mechanical ventilation, IMV invasive mechanical ventilation, HIV human immunodeficiency virus, ARDS acute respiratory distress syndrome