Awake prone positioning of hypoxaemic patients with COVID-19 : protocol for a randomised controlled open-label superiority meta-trial - Tavernier, Elsa (Clinical Investigation Center, INSERM 1415 (França)) ; McNicholas, Bairbre (Saolta University Hospital Group) ; Pavlov, Ivan (Hopital de Verdun) ; Roca, Oriol (Universitat Autònoma de Barcelona) ; Perez, Yonatan (CHU Tours) ; Laffey, John (Saolta University Hospital Group) ; Mirza, Sara (Rush University) ; Cosgrave, David (Saolta University Hospital Group) ; Vines, David (Rush University) ; Frat, Jean-Pierre (CHU Poitiers) ; Ehrmann, Stephan (CHU Tours) ; Li, Jie (Rush University)