[1] Vanderbilt Univ Sch Med, Ctr Hlth Serv Res, Nashville, TN 37232 USA
[2] Poliambulanza Hosp, Dept Internal Med & Geriatr, Brescia, Italy
[3] Geriatr Res Grp, Brescia, Italy
[4] Vanderbilt Univ Sch Med, Div Allergy Pulm Crit Care Med, Nashville, TN 37232 USA
[5] Vanderbilt Univ Sch Med, Dept Psychiat, Nashville, TN 37232 USA