1. Center for Health Services Research in Primary Care, Durham Veterans Affairs Medical Center, Durham, North Carolina
2. Health Services Research, Richard L. Roudebush Veterans Affairs Medical Center, Regenstrief Institute for Health Care, and Division of General Internal Medicine, Indiana University School of Medicine, Indianapolis, Indiana
3. Center for Health Services Research in Primary Care, Durham Veterans Affairs Medical Center, Durham, North Carolina, and Division of General Internal Medicine, Department of Medicine, Duke University Medical Center, Durham, North Carolina