[1] Harvard Med Sch, Dept Hlth Care Policy, 180A Longwood Ave, Boston, MA 02115 USA
[2] Stanford Univ, Ctr Hlth Policy, Stanford, CA 94305 USA
[3] Brigham & Womens Hosp, Dept Med, Div Gen Internal Med & Primary Care, 75 Francis St, Boston, MA 02115 USA
[4] Harvard TH Chan Sch Publ Hlth, Dept Hlth Policy & Management, Boston, MA USA
[5] RAND Corp, Arlington, VA USA
[6] Beth Israel Deaconess Med Ctr, Div Gen Med, Boston, MA 02215 USA