Activity Number:
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25
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Type:
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Invited
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Date/Time:
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Sunday, August 11, 2002 : 4:00 PM to 5:50 PM
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Sponsor:
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ENAR
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Abstract - #300073 |
Title:
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Measuring Dementia from Multidimensional Longitudinal Data
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Author(s):
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Ron Brookmeyer*+ and Maria Corrada and Tom Travison
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Affiliation(s):
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Johns Hopkins School of Public Health and Johns Hopkins University and Johns Hopkins School of Public Health
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Address:
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615 N. Wolfe Street, Baltimore, Maryland, 21205-2103, USA
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Keywords:
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dementia ; longitudinal data ; multidimensional ; clinical trials ; Alzheimer's disease
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Abstract:
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Dementia is an important public health problem as the population ages. The analysis of dementia studies involve complex challenges. The main complexity is that there is no universally accepted measure of dementia. Often, either a battery of neuropsychological tests or a global scale such as the clinical dementia rating (CDR) scale is used to measure treatment efficacy. The statistical problem is how to summarize the numerous measurements collected on an individual through time to best quantify the treatment effect. Measurements such as the mini-mental test or other cognitive tests may be on different numerical scales. One approach is to conceptualize the treatment effect as a parameter that alters the biological clock associated with the time trajectory of each of the neuropsychological test scores. Another approach is to assume the treatment transforms the quantiles of the distribution of each test score, and that the transformation is similar across scores. A third approach is to use the CDR as an overall measure. The strengths and weaknesses of the various approaches are considered. The methods are applied to a study of Alzheimer's disease.
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