1 Caisse Nationale de l'Assurance Maladie, Paris, France.
2 Bloomsbury Institute for Intensive Care Medicine, Division of Medicine, University College London, London, United Kingdom.
3 Clinical Trials Methods and Outcomes Lab, PAIR (Palliative and Advanced Illness Research) Center & Department of Biostatistics, Epidemiology, and Informatics, Perelman School of Medicine University of Pennsylvania, Philadelphia, Pennsylvania.
4 Department of Anesthesia and Intensive Care Unit, Assistance Publique Hôpitaux de Marseille, Hospital Nord, Aix-Marseille University, Marseille, France.
5 Division of Critical Care Medicine, Department of Anesthesia and Perioperative Care, University of California, San Francisco, San Francisco, California; and.