1 Center for Health Services Research in Primary Care, Durham Veterans Affairs Medical Center, Durham, North Carolina.
2 Department of Population Health Sciences, Duke University School of Medicine, Durham, North Carolina.
3 Division of General Internal Medicine, Department of Medicine, Duke University School of Medicine, Durham, North Carolina.
4 The Comparative Health Outcomes, Policy, and Economics (CHOICE) Institute, Departments of Pharmacy, Health Services, and Economics, University of Washington, Seattle.