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Activity Number:
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442
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Type:
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Contributed
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Date/Time:
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Wednesday, August 6, 2008 : 2:00 PM to 3:50 PM
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Sponsor:
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Section on Statistics and the Environment
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| Abstract - #302250 |
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Title:
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Imputation of the Physical Activity Component of Gerontologic Frailty for Use in Modeling the Health Effects of Air Pollution on Older Adults in the Cardiovascular Health Study
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Author(s):
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Sandrah P. Eckel*+ and Thomas A. Louis and Karen Bandeen-Roche and Paulo Chaves and Linda P. Fried and Helene G. Margolis
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Companies:
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Johns Hopkins Bloomberg School of Public Health and Johns Hopkins University and Johns Hopkins Bloomberg School of Public Health and Johns Hopkins Bloomberg School of Public Health and Johns Hopkins Medical Institutions and California Department of Public Health
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Address:
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Department of Biostatistics, Baltimore, MD, 21205,
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Keywords:
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effect modification ; air pollution effects ; geriatrics ; missing data
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Abstract:
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Our goal is to develop, evaluate and apply statistical methods to assess the hypothesis that the health effects of air pollution are modified by underlying gerontologic frailty status as well as age and comorbidity. We use data from the Cardiovascular Health Study (CHS) and the CHS Environmental Factors Ancillary Study. In gerontology, frail individuals are characterized by slow walking speed, exhaustion, unintended weight loss, weakness and low physical activity. In CHS, physical activity was measured only at a subset of visits. To fill in missing values, we develop a longitudinal frailty status variable using surrogate measures of physical activity to impute low Kcal/week expenditure for the missing values. We report on the imputation method and on initial analyses of the modifying effect of frailty on air pollution and health associations.
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