Patient characteristics
| High risk | Low risk | p-value | |
| Patients n | 90 | 399 | |
| Age years, mean±sd | 63.2±12.6 | 61.5±15.2 | 0.30 |
| Male, n (%) | 63 (70) | 269 (67.4) | 0.73 |
| Admission type, n (%) | 0.30 | ||
| Medical | 72 (80) | 287 (71.9) | |
| Planned surgical | 8 (8.9) | 49 (12.3) | |
| Emergency surgical | 10 (11.1) | 63 (15.8) | |
| APACHEII score, median (IQR) | 20 (15–24) | 20 (15–26) | 0.13 |
| MV duration in hours prior to inclusion, median (IQR) | 18 (6–32) | 21 (14–30) | 0.10 |
| FIO2 %, median (IQR) | 0.69 (0.60–0.74) | 0.31 (0.25–0.40) | |
| Pmax cmH2O, median (IQR) | 25 (21–30) | 19.5 (16–25) | <0.001 |
| PEEP cmH2O, median (IQR) | 10 (8–12) | 8 (5–8.5) | <0.001 |
| ICU LOS days, median (IQR) | 9 (5–19) | 6 (3–11.8) | 0.001 |
| ICU mortality, n (%) | 39 (43.3) | 124 (31.1) | 0.067 |
MV: mechanical ventilation; FIO2: inspiratory oxygen fraction; Pmax: maximum airway pressure; PEEP: positive end-expiratory pressure; ICU: intensive care unit; LOS: length of stay.