Baseline characteristics
| Variable | Before matching | After matching | ||||
| NIV (n=81) | Intubation (n=94) | P value | NIV (n=79) | Intubation (n=79) | P value | |
| Age | 55.1 | 58.5 | 0.078 | 58 (27.67) | 57 (27.81) | 0.206 |
| Female (%) | 36 (44.4) | 47 (50) | 0.463 | 35 (44.3) | 39 (49.3) | 0.524 |
| Median APACHE II score | 19 (9) | 22 (9) | 0.029 | 19 (9) | 21 (9) | 0.111 |
| Median PF ratio | 105 (71.32) | 92 (52.95) | 0.042 | 105 (72.69) | 96 (55.03) | 0.075 |
| Median Charlson comorbidity index | 3 (4) | 3 (3) | 0.465 | 3 (4) | 2 (3) | 0.306 |
| Median creatinine (μg/mL) | 99 (111.5) | 89.5 (107) | 0.728 | 99 (105) | 88 (98) | 0.712 |
| Median bilirubin (μmol/L) | 10 (11) | 11 (12) | 0.960 | 10 (11) | 11 (13.5) | 0.642 |
| Median platelet (×109/L) | 215 (183.5) | 222 (202.5) | 0.992 | 215 (177) | 223 (199.5) | 0.613 |
| Median GCS score | 15 (0) | 15 (1) | 0.147 | 15 (0) | 15 (14.5) | 0.132 |
| Immunocompromised (%) | 23 (28.3) | 29 (30.8) | 0.722 | 23 (29.1) | 26 (32.9) | 0.606 |
| Cause of AHRF | 0.025 | 0.033 | ||||
| Viral pneumonia | 16 | 25 | 16 | 20 | ||
| Bacterial pneumonia | 42 | 48 | 41 | 40 | ||
| Aspiration pneumonia | 1 | 7 | 1 | 7 | ||
| Other | 22 | 14 | 21 | 12 | ||
Values in brackets represent IQR unless otherwise specified.
AHRF, acute hypoxaemic respiratory failure; APACHE II, Acute Physiology and Chronic Health Evaluation II; GCS, Glasgow Coma Scale; NIV, non-invasive ventilation; PF, partial pressure oxygen to fraction of inspired oxygen.