[1] W Virginia Univ, Ctr Aging, Morgantown, WV 26506 USA
[2] W Virginia Univ, Dept Community Med, Morgantown, WV 26506 USA
[3] Duke Univ, Dept Psychiat & Behav Sci, Durham, NC USA
[4] Univ Michigan, Dept Hlth Management & Policy, Ann Arbor, MI 48109 USA