1. From the Departments of Medicine (A.R.K., C.L.R., R.L.R.), Pediatrics (A.R.K., C.L.R., A.B.D., R.L.R.), Biostatistics (H.N.), and Orthopaedics and Rehabilitation (A.R.K., A.B.D.), Vanderbilt University Medical Center, Nashville, TN; and Geriatric Research Education and Clinical Center, Veterans Affairs Tennessee Valley Healthcare System, Nashville, TN (A.R.K., C.L.R., R.L.R.).