[1] Univ N Carolina, Gillings Sch Global Publ Hlth, Chapel Hill, NC 27515 USA
[2] Wake Forest Sch Med, Dept Pediat, Med Ctr Blvd, Winston Salem, NC USA
[3] Wake Forest Sch Med, Dept Epidemiol & Prevent, Div Publ Hlth Sci, Winston Salem, NC 27101 USA
[4] Wake Forest Sch Med, Dept Internal Med, Winston Salem, NC 27101 USA
[5] Harvard Med Sch, Ctr Primary Care, Boston, MA 02115 USA
[6] Collect Hlth, Res & Populat Hlth, San Francisco, CA USA
[7] Imperial Coll London, Sch Publ Hlth, London, England
[8] Univ Calif San Francisco, Div Gen Internal Med, San Francisco, CA 94143 USA
[9] San Francisco Gen Hosp, Ctr Vulnerable Populat, San Francisco, CA 94110 USA
[10] Trauma Ctr, San Francisco, CA USA
[11] Univ N Carolina, Sch Med, Dept Med, Div Gen Med & Clin Epidemiol, Chapel Hill, NC 27515 USA
[12] Univ N Carolina, Cecil G Sheps Ctr Hlth Serv Res, Chapel Hill, NC 27515 USA