[1] Univ North Carolina Chapel Hill, Cecil G Sheps Ctr Hlth Serv Res, Chapel Hill, NC USA
[2] Univ North Carolina Chapel Hill, Sch Med, Div Geriatr Med, Chapel Hill, NC USA
[3] Univ North Carolina Chapel Hill, Sch Med, Dept Family Med, Chapel Hill, NC USA
[4] Univ Pittsburgh, Sch Med, Div Geriatr Med, Pittsburgh, PA 15260 USA
[5] Hamamatsu Univ Sch Med, Dept Family & Community Med, Hamamatsu, Japan
[6] Lake Erie Coll Osteopath Med, Bradenton, FL USA
[7] Univ Michigan, Sch Med, Dept Family Med, Ann Arbor, MI USA
[8] Univ North Carolina Chapel Hill, Gillings Sch Global Publ Hlth, Dept Biostat, Chapel Hill, NC USA