[1] Boston Med Ctr, Sect Gen Internal Med, Boston, MA USA
[2] Boston Univ, Sch Med, Dept Biomed Sci, Boston, MA 02118 USA
[3] Boston Univ, Sch Publ Hlth, Dept Community Hlth Sci, Boston, MA USA
[4] Harvard Univ, Sch Publ Hlth, Dana Farber Canc Inst, Boston, MA 02115 USA
[5] Harvard Univ, Sch Publ Hlth, Dept Populat Med, Boston, MA 02115 USA
[6] Harvard Pilgrim Hlth Care, Boston, MA USA
[7] Harvard Univ, Sch Med, Dept Hlth Care Policy, Boston, MA 02115 USA
[8] Brigham & Womens Hosp, Div Gen Med, Boston, MA 02115 USA
[9] Cambridge Hlth Alliance, Sch Med, Dept Med, Cambridge, MA 02138 USA
[10] Cambridge Hlth Alliance, Sch Med, Dept Community Affairs, Cambridge, MA 02138 USA
[11] Harvard Univ, Sch Med, Cambridge, MA 02138 USA