[1] Univ Michigan, Div Gen Med, Dept Internal Med, Sch Med, Ann Arbor, MI 48109 USA
[2] Univ Michigan, Ctr Healthcare Outcomes & Policy, Ann Arbor, MI 48109 USA
[3] Univ Michigan, Inst Healthcare Policy & Innovat, Ann Arbor, MI 48109 USA
[4] Vet Affairs Ann Arbor Healthcare Syst, Ann Arbor, MI USA
[5] Univ Michigan, Sch Publ Hlth, Dept Hlth Management & Policy, Ann Arbor, MI 48109 USA
[6] Univ Michigan, Dept Econ, Ann Arbor, MI 48109 USA
[7] Natl Bur Econ Res, Cambridge, MA 02138 USA
[8] Univ Michigan, Inst Social Res, Ann Arbor, MI 48109 USA
[9] Harvard Univ, Sch Publ Hlth, Dept Hlth Policy & Management, Boston, MA 02115 USA
[10] Brigham & Womens Hosp, Div Gen Internal Med, Boston, MA 02115 USA
[11] Harvard Univ, Sch Med, Boston, MA USA