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Activity Number:
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233
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Type:
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Contributed
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Date/Time:
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Monday, August 3, 2009 : 2:00 PM to 3:50 PM
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Sponsor:
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Biopharmaceutical Section
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| Abstract - #305454 |
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Title:
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Which MRI Measure is Best for Alzheimer's Disease Prevention Trials: Statistical Considerations of Power and Sample Size
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Author(s):
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Steven D. Edland*+
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Companies:
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University of California, San Diego
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Address:
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9500 Gilman Dr. M/C 0949 , La Jolla, CA, 92093,
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Keywords:
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clinical trial ; sample size ; power ; volumetric MRI ; surrogate outcome ; Alzheimer's disease
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Abstract:
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Neuroimaging measures have been proposed as surrogate outcomes for clinical trials of treatments to slow progression of disease within subjects with mild cognitive impairment (MCI). We explored the relative efficiency of neuroimaging measures as outcomes in an MCI trial using data from the Alzheimer's Disease Neuroimaging Initiative. Ventricular enlargement was the most efficient outcome when powering to detect a slowing of all cause age-associated atrophy. Middle temporal cortex atrophy was the most efficient outcome when powering to detect a slowing of disease-specific atrophy defined as the decline experienced by MCI subjects that is above and beyond the decline experienced by age-matched cognitively normal subjects. Consideration of the putative target of treatment is critical to distinguishing which brain regions are most suitable as outcome measures for clinical trials.
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