[1] Tufts Univ, Sch Med, Dept Med, Boston, MA 02111 USA
[2] Tufts Med Ctr, Inst Clin Res & Hlth Policy Studies, 800 Washington St,Box 63, Boston, MA 02111 USA
[3] Univ Michigan, Dept Family Med, Ann Arbor, MI 48109 USA
[4] Univ Michigan, Inst Healthcare Policy & Innovat, Ann Arbor, MI 48109 USA
[5] Univ Michigan, Div Gen Med, Ann Arbor, MI 48109 USA
[6] Dept Vet Affairs, Ctr Clin Management Res, Ann Arbor, MI USA
[7] Michigan State Univ, Coll Human Med, E Lansing, MI 48824 USA
[8] Michigan Primary Care Assoc, Lansing, MI USA
[9] Northwestern Univ, Dept Pediat, Feinberg Sch Med, Chicago, IL 60611 USA
[10] Northwestern Univ, Dept Med Social Sci, Feinberg Sch Med, Chicago, IL 60611 USA
[11] Ann & Robert H Lurie Childrens Hosp Chicago, Chicago, IL 60611 USA