1. From the Center for Clinical Health Policy Research (G.P.S., J.B., J.L., D.B.M.) and the Departments of Community and Family Medicine (G.P.S.) and Medicine (G.P.S., D.B.M.), Duke University School of Medicine Durham, NC; the Sanford Institute for Public Policy (J.L.), Duke University, Durham, NC; Center for Health Services Research in Primary Care (D.B.M.), Department of Veterans Affairs Medical Center, Durham NC.