[1] Univ Ferrara, Dept Med Sci, I-44100 Ferrara, Italy
[2] IRCCS INRCA, Dept Geriatr, Ancona, Italy
[3] Univ Perugia, Inst Gerontol & Geriatr, I-06100 Perugia, Italy
[4] Univ Cattolica Sacro Cuore, Dept Gerontol & Geriatr Sci, Rome, Italy
[5] Univ Parma, Dept Clin & Expt Med, Sect Geriatr, I-43100 Parma, Italy
[6] Univ Hosp Parma, Geriatr Clin Unit, Parma, Italy
[7] Azienda Sanit Firenze, Geriatr Rehabil Unit, Florence, Italy
[8] Univ Maryland, Sch Med, Dept Epidemiol & Publ Hlth, Baltimore, MD 21201 USA
[9] NIA, Longitudinal Studies Sect, Clin Res Branch, Baltimore, MD 21224 USA