Proportional Hazards Models

Publication Title: 
Neurology

OBJECTIVE: To examine the relative risk and population attributable risk (PAR) of death with dementia of varying type and severity and other risk factors in a population of exceptional longevity. METHODS: Deaths were monitored over 5 years using vital statistics records and newspaper obituaries in 355 individuals with prevalent dementia and 4,328 without in Cache County, UT. Mean age was 83.3 (SD 7.0) years with dementia and 73.7 (SD 6.8) years without. History of coronary artery disease, hypertension, diabetes, and other life-shortening illness was ascertained from interviews.

Author(s): 
Tschanz, J. T.
Corcoran, C.
Skoog, I.
Khachaturian, A. S.
Herrick, J.
Hayden, K. M.
Welsh-Bohmer, K. A.
Calvert, T.
Norton, M. C.
Zandi, P.
Breitner, J. C. S.
Cache County Study Group
Publication Title: 
The Journals of Gerontology. Series A, Biological Sciences and Medical Sciences

Tissue damage due to oxidative stress has been implicated in aging, memory loss, and cataract formation. We hypothesized that persons who achieved exceptional longevity with preserved cognition (successful aging [SAG]) would exhibit a lower rate of age-related cataract (ARC) than the general population. The age-specific rates of ARC for a group of 100 (50 male, 50 female) elderly persons who reached at least age 90 years with preserved cognition were compared to the corresponding rates of ARC reported in five population-based studies.

Author(s): 
Zubenko, George S.
Zubenko, Wendy N.
Maher, Brion S.
Wolf, Norman S.
Publication Title: 
Aging Cell

We investigated the hypothesis that gene expression profiles in cultured cell lines from adults, aged 57-97 years, contain information about the biological age and potential longevity of the donors. We studied 104 unrelated grandparents from 31 Utah CEU (Centre d'Etude du Polymorphisme Humain - Utah) families, for whom lymphoblastoid cell lines were established in the 1980s.

Author(s): 
Kerber, Richard A.
O'Brien, Elizabeth
Cawthon, Richard M.
Publication Title: 
Age and Ageing

INTRODUCTION: parental age at conception may affect life expectancy. Adult daughters of older fathers seem to live shorter lives and, in one study, being born to a mother aged <25 was an important predictor of exceptional longevity. The effect of parental age on fitness/frailty in late life is unknown. We aimed to investigate the relationships between parental age and frailty and longevity in older adults. METHODS: in the Canadian Study of Health and Aging (CSHA), data was collected on individuals aged >or=65 using a Self-Assessed Risk Factor Questionnaire and screening interview.

Author(s): 
Hubbard, Ruth E.
Andrew, Melissa K.
Rockwood, Kenneth
Publication Title: 
Journal of the American Geriatrics Society

OBJECTIVES: To determine whether offspring of parents with exceptional longevity (OPEL) have a lower rate of dementia than offspring of parents with usual survival (OPUS). DESIGN: Community-based prospective cohort study. SETTING: Bronx, New York. PARTICIPANTS: A volunteer sample of 424 community-residing older adults without dementia aged 75 to 85 recruited from Bronx County starting in 1980 and followed for up to 23 years. MEASUREMENTS: Epidemiological, clinical, and neuropsychological assessments were completed every 12 to 18 months.

Author(s): 
Lipton, Richard B.
Hirsch, Jamie
Katz, Mindy J.
Wang, Cuiling
Sanders, Amy E.
Verghese, Joe
Barzilai, Nir
Derby, Carol A.
Publication Title: 
Biogerontology

Leukocyte telomere length is widely considered a biomarker of human age and in many studies indicative of health or disease. We have obtained quantitative estimates of telomere length from blood leukocytes in a population sample, confirming results of previous studies that telomere length significantly decreases with age. Telomere length was also positively associated with several measures of healthy aging, but this relationship was dependent on age.

Author(s): 
Kim, Sangkyu
Bi, Xiuhua
Czarny-Ratajczak, Malwina
Dai, Jianliang
Welsh, David A.
Myers, Leann
Welsch, Michael A.
Cherry, Katie E.
Arnold, Jonathan
Poon, Leonard W.
Jazwinski, S. Michal
Publication Title: 
Journal of the American Geriatrics Society
Author(s): 
Shavelle, Robert
Paculdo, David
Publication Title: 
Journal of thrombosis and haemostasis: JTH

BACKGROUND: Thromboprophylaxis with rivaroxaban (R) is superior to enoxaparin in patients undergoing major orthopedic surgery (MOS). However, rivaroxaban has never been directly compared with fondaparinux (F), which also shows superior efficacy over enoxaparin. The clinical impact of switching from fondaparinux to rivaroxaban thromboprophylaxis is unclear. OBJECTIVES: To evaluate the efficacy and safety of rivaroxaban or fondaparinux thromboprophylaxis in unselected patients undergoing MOS.

Author(s): 
Beyer-Westendorf, J.
L¸tzner, J.
Donath, L.
Radke, O. C.
Kuhlisch, E.
Hartmann, A.
Weiss, N.
Werth, S.
Publication Title: 
Journal of Human Genetics

Bivariate survival models with discretely distributed frailty based on the major gene concept and applied to the data on related individuals such as twins and sibs can be used to estimate the underlying hazard, the relative risk and the frequency of the longevity allele. To determine the position of the longevity gene, additional genetic markers data are needed. If the action of the longevity allele does not depend on its position in the genome, these two problems can be solved separately using a two-step procedure.

Author(s): 
Begun, Alexander
Publication Title: 
American Journal of Public Health

OBJECTIVES: Vitamin and mineral supplementation is a common practice in the United States, yet little is known about the long-term health effects of regular supplement use. METHODS: To examine the relationship between reported use of supplements and mortality, we analyzed data from US adults 25 to 74 years of age who were examined in the First National Health and Nutrition Examination Survey (1971 to 1975), with vital status determined through 1987. RESULTS: At baseline, 22.5% of the cohort reported using supplements regularly and 10.0% reported irregular use.

Author(s): 
Kim, I.
Williamson, D. F.
Byers, T.
Koplan, J. P.

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