[1] Univ Michigan, Sch Med, Dept Pediat, 300 North Ingalls St,SPC 5456,Room 6E18, Ann Arbor, MI 48109 USA
[2] Univ Michigan, Sch Med, Susan B Meister Child Hlth Evaluat & Res Ctr, Ann Arbor, MI 48109 USA
[3] Boston Univ, Questrom Sch Business, Inst Hlth Syst Innovat & Policy, Boston, MA 02215 USA
[4] Boston Univ, Questrom Sch Business, Dept Markets Publ Policy & Law, Boston, MA 02215 USA
[5] Univ Chicago, Dept Med, Sect Gen Internal Med, 5841 S Maryland Ave, Chicago, IL 60637 USA
[6] Univ Chicago, Sect Acad Pediat, Chicago, IL 60637 USA