1. Michael E. DeBakey Department of Surgery, Baylor College of Medicine, Houston, Texas
2. Center for Innovations in Quality, Effectiveness, and Safety, Michael E. DeBakey VA Medical Center, Houston, Texas
3. Boston University Medical School, Boston, Massachusetts
4. VA Boston Health Care System, Boston, Massachusetts
5. Department of Surgery, University of Alabama at Birmingham
6. Birmingham VA Medical Center, Birmingham, Alabama