1. VA Pittsburgh Healthcare System and Division of Cardiothoracic Surgery-University of Pittsburgh School of Medicine, Pittsburgh, PA
2. Denver Veterans Affairs Medical Center, University of Colorado Health Sciences Center School of Medicine, Department of Medicine, Surgery, and Pathology, Cooperative Studies Program National Coordinator and Continuous Improvement in Cardiac Surgery Program, Denver, CO
3. Veterans Affairs Cooperative Studies Program Coordinating Center, VA Maryland, Healthcare System, Perry Point, MD and University of Maryland School of Medicine, Department of Epidemiology and Preventive Medicine, Baltimore, MD
4. University of South Florida, Tampa General Hospital, James A. Haley Veterans Administration Hospital, Tampa, FL.