[1] Univ Michigan, Sch Dent, Dept Biol & Mat Sci, Ann Arbor, MI 48109 USA
[2] Univ Michigan, Sch Publ Hlth, Dept Biostat, Ann Arbor, MI 48109 USA
[3] Vet Affairs Med Ctr, Ann Arbor, MI USA
[4] Univ Michigan, Sch Med, Dept Internal Med, Div Geriatr Med, Ann Arbor, MI USA