[1] VA Puget Sound Health Care System and the University of Washington,Department of Surgery
[2] Hines VA Cooperative Studies Program Coordinating Center,Tenet Health System
[3] University of Colorado Health Outcomes Program,Department of Surgery
[4] Harvard Medical School,Department of Surgery
[5] Center for Health System Design and Evaluation Institute for Health Policy,undefined
[6] VA Boston Healthcare System,undefined
[7] Feinberg School of Medicine,undefined
[8] Northwestern University,undefined
[9] VA Puget Sound Health Care System,undefined