[1] Indiana Univ, Ctr Aging Res, Indianapolis, IN 47405 USA
[2] Regenstrief Inst Hlth Care, Indianapolis, IN USA
[3] Univ N Carolina, Dept Biostat, Chapel Hill, NC 27515 USA
[4] Univ N Carolina, Dept Emergency Med, Chapel Hill, NC 27515 USA
[5] Watauga Med Ctr, Boone, NC USA
[6] Univ North Carolina Hosp, Chapel Hill, NC USA
[7] Univ Penn, Dept Emergency Med, Philadelphia, PA 19104 USA
[8] Univ N Carolina, Div Geriatr, Chapel Hill, NC 27515 USA
[9] Ctr Aging & Hlth, Chapel Hill, NC USA