1 Department of Anaesthesiology, Duke University School of Medicine, Durham, NC, USA; Critical Care and Perioperative Population Health Research Unit, Department of Anaesthesiology, Duke University School of Medicine, Durham, NC, USA.
2 Critical Care and Perioperative Population Health Research Unit, Department of Anaesthesiology, Duke University School of Medicine, Durham, NC, USA; Department of Economics, Duke University, Durham, NC, USA.
3 Critical Care and Perioperative Population Health Research Unit, Department of Anaesthesiology, Duke University School of Medicine, Durham, NC, USA; Fuqua School of Business, Duke University, Durham, NC, USA.
4 Critical Care and Perioperative Population Health Research Unit, Department of Anaesthesiology, Duke University School of Medicine, Durham, NC, USA.
5 Critical Care and Perioperative Population Health Research Unit, Department of Anaesthesiology, Duke University School of Medicine, Durham, NC, USA; Department of Anaesthesiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
6 Critical Care and Perioperative Population Health Research Unit, Department of Anaesthesiology, Duke University School of Medicine, Durham, NC, USA; Department of Anaesthesiology, University of California at San Francisco, San Francisco, CA, USA.
7 Department of Anaesthesiology, Duke University School of Medicine, Durham, NC, USA; Critical Care and Perioperative Population Health Research Unit, Department of Anaesthesiology, Duke University School of Medicine, Durham, NC, USA; Durham VA Healthcare System, Durham, NC, USA. Electronic address: [email protected].