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Activity Number:
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537
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Type:
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Contributed
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Date/Time:
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Thursday, August 2, 2007 : 10:30 AM to 12:20 PM
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Sponsor:
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Biometrics Section
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| Abstract - #310085 |
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Title:
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The Exact Distribution of the Heterogeneity Statistic in Meta-Analysis
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Author(s):
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Brad Biggerstaff*+ and Dan Jackson
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Companies:
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Centers for Disease Control and Prevention and University of Salford
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Address:
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PO Box 2087, Fort Collins, CO, 80522-2087,
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Keywords:
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meta-analysis ; homogeneity test ; heterogeneity ; West Nile virus
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Abstract:
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The exact distribution of Cochran's heterogeneity statistic Q in one-way meta-analysis is derived, and software is provided to facilitate computation. The exact Q-distribution is used to derive the exact distributions of the heterogeneity measures I^2, H^2 and H^2_M, and also of the DerSimonian-Laird estimator of the heterogeneity variance parameter. Comparisons of standard approximations are made to the exact results in applications appearing in the literature and of a meta-analysis of West Nile virus studies of clinical to sub-clinical infection ratios.
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