[1] Harvard Univ, PhD Program Hlth Policy, Boston, MA 02115 USA
[2] Inst Community Hlth, Cambridge, MA USA
[3] Harvard Sch Publ Hlth, Dept Hlth Policy & Management, Boston, MA USA
[4] Boston Childrens Hosp, Gen Pediat, Boston, MA USA
[5] Harvard Pilgrim Hlth Care Inst, Dept Populat Med, Boston, MA USA
[6] Harvard Med Sch, Boston, MA USA
[7] Brigham & Womens Hosp, Dept Med, Primary Care, 75 Francis St, Boston, MA 02115 USA
[8] Boston Childrens Hosp, Div Gen Pediat, Pediat, Boston, MA USA