[1] Univ Florida, Inst Aging, Gainesville, FL USA
[2] Univ Ferrara, Dept Clin & Expt Med, I-44100 Ferrara, Italy
[3] Wake Forest Univ, Sticht Ctr Aging, Winston Salem, NC 27109 USA
[4] NIA, Lab Epidemiol Demog & Biometry, IRP, Bethesda, MD 20892 USA
[5] Univ Pittsburgh, Dept Epidemiol, Pittsburgh, PA 15261 USA
[6] Univ Calif San Francisco, Dept Med, San Francisco, CA 94143 USA
[7] Univ Tennessee, Dept Prevent Med, Memphis, TN 38163 USA
[8] Univ Lausanne, CH-1015 Lausanne, Switzerland