作者单位:RAND Corporation, Pittsburgh, PA, United States, H. John Heinz School of Public Policy and[1]University of Pittsburgh, School of Medicine, Pittsburgh, PA, United States[2]RAND Corporation, Boston, MA, United States, Division of General Internal Medicine, Brigham and[3]RAND Corporation, Pittsburgh, PA, United States[4]University of Pittsburgh, School of Medicine, Pittsburgh, PA, United States, RAND Corporation[5]