1. Group Health Research Institute, Seattle, Washington2Division of General Internal Medicine, Department of Medicine, University of Washington, Seattle
2. Center for Health Services Research in Primary Care, Durham Veterans Affairs Medical Center, Durham, North Carolina4Department of Biostatistics and Bioinformatics, Duke University, Durham, North Carolina
3. Center for Health Services Research in Primary Care, Durham Veterans Affairs Medical Center, Durham, North Carolina
4. Veterans Administration North Texas Health Care System, Dallas6Division of Gastrointestinal and Endocrine Surgery, University of Texas Southwestern Medical Center, Dallas7Division of General Surgery, Northwestern University, Chicago, Illinois8Deputy Edito
5. Center for Health Services Research in Primary Care, Durham Veterans Affairs Medical Center, Durham, North Carolina9Division of General Internal Medicine, Department of Medicine, Duke University, Durham, North Carolina
6. Pittsburgh Veterans Affairs Medical Center, Pittsburgh, Pennsylvania11Division of Minimally Invasive Surgery, Department of Surgery, Allegheny Health Network, Temple University, Philadelphia, Pennsylvania