| First author [ref.] | |||||
| Gattinoni [31] | Guérin [32] | Mancebo [33] | Taccone [34] | Guérin [2] | |
| Year of trial | 2001 | 2004 | 2006 | 2009 | 2013 |
| Protective lung ventilation | No | No | No | Yes | Yes |
| Long prone sessions | No | No | Yes | Yes | Yes |
| Target population | ALI/ARDS | Hypoxaemic acute respiratory failure | ARDS | ARDS | ARDS with severity criteria |
| Crossover allowed | Yes | Yes | Yes | No (rescue) | No (rescue) |
| Rate of crossover | Not reported | 81 (21.4%) out of 378 | 5 (8.1%) out of 62 | 20 (11.5%) out of 174 | 17 (7.4%) out of 229 |
ALI: acute lung injury; ARDS: acute respiratory distress syndrome.