1. Department of Medicine, Geriatrics Division, University of Verona, Italy.
2. Department of Medicinal Sciences, University of Ferrara, Italy.
3. Geriatric Unit, Local Health Authority-Tuscany Centre, Florence, Italy.
4. Department of Epidemiology and Public Health, University of Maryland School of Medicine, Baltimore.
5. Longitudinal Studies Section, Clinical Research Branch, National Institute on Aging, National Institutes of Health, Baltimore, Maryland.