[1] Univ Michigan, Simpson Mem Inst 208, Dept Internal Med, Ann Arbor, MI 48109 USA
[2] Univ Texas Med Branch, Dept Internal Med, Galveston, TX USA
[3] Univ Texas Med Branch, Dept Prevent Med & Community Hlth, Galveston, TX USA
[4] Univ Texas Med Branch, Sealy Ctr Aging, Galveston, TX USA
[5] Univ Florida, Coll Med, Dept Urol, Gainesville, FL USA