From the *Brockton/West Roxbury VA Medical Center, West Roxbury, Massachusetts, Harvard Medical School, Boston, Massachusetts, Brigham and Women's Hospital, Boston, Massachusetts; †Brockton/West Roxbury VA Medical Center, West Roxbury, Massachusetts, Harvard Medical School, Boston, Massachusetts, Division of General Medicine and Primary Care, Beth Israel Deaconess Medical Center, Boston, Massachusetts; ‡Hines VA Center for Cooperative Studies in Health Services, Hines, Illinois; §Department of Surgery, University of Texas Health Science Center, San Antonio, Texas; ∥Veterans Integrated Service Network 17, Grand Prairie, Texas; ¶Tampa VA Medical Center, Tampa, Florida, University of South Florida College of Medicine, Tampa, Florida; #Denver VA Medical Center, Denver, Colorado, University of Colorado Health Sciences Center, Denver, Colorado; **University of Miami Department of Surgery, Miami, Florida, University of Miami School of Medicine, Miami, Florida, Miami VA Medical Center, Miami, Florida; ††Department of Surgery, Department of Veterans Affairs Headquarters, Washington DC; ‡‡West Los Angeles VA Medical Center, West Los Angeles, California, University of California Los Angeles, Los Angeles, California; §§Veterans Integrated Service Network 11, Ann Arbor, Michigan; ∥∥Department of Anesthesia, National Anesthesia Services, Iowa City, Iowa; ¶¶Pittsburgh VA Medical Center, Pittsburgh, Pennsylvania, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania