[1] Univ Penn, Sch Med, Sect Publ Hlth, Dept Family Med & Community Hlth, Philadelphia, PA 19104 USA
[2] Univ Penn, Sch Med, Leonard Davis Inst Hlth Econ, Philadelphia, PA 19104 USA
[3] Univ Penn, Sch Med, Ctr Publ Hlth Initiat, Philadelphia, PA 19104 USA
[4] Philadelphia VA Med Ctr, Philadelphia, PA USA
[5] Univ Penn, Sch Med, Dept Med, Philadelphia, PA 19104 USA
[6] Univ Penn, Wharton Sch, Hlth Care Management Dept, Philadelphia, PA 19104 USA