1 Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University School of Medicine, Stanford University, Stanford, California, [email protected] Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts Department of Anesthesiology, Hospital for Special Surgery, New York, New York Department of Anesthesiology and Critical Care, University of Pennsylvania School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University School of Medicine, Stanford University, Stanford, California, Anesthesiology and Perioperative Care Service, Veterans Affairs Palo Alto Health Care System, Palo Alto, California Department of Health Research and Policy, Stanford University School of Medicine, Stanford University, Stanford, California, National Bureau of Economic Research, Cambridge, Massachusetts.