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Activity Number:
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224
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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 - #303935 |
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Title:
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Handling Baseline Responses in Repeated Measures Analyses with Data Missing at Random
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Author(s):
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Phillip Dinh*+ and Peiling Yang
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Companies:
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FDA and FDA
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Address:
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10903 New Hampshire Ave, Silver Spring, MD, 20993-0002,
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Keywords:
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Baseline ; Longitudinal Data ; Missing Data ; MMRM
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Abstract:
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The objective of this paper is to compare five strategies for handling baseline responses in an MMRM analysis when missing data are present. The five strategies are: 1) retain the baseline response as part of the outcome vector and make no assumptions about group differences in the mean response at baseline; 2) retain the baseline as part of the outcome vector and assume the group means are equal at baseline; 3) subtract the baseline from all of the remaining post-baseline responses, and analyze the differences from baseline; 4) Use the baseline as a covariate in the analysis of the post-baseline responses, assuming homogeneous regression slopes; 5) Use the baseline as a covariate in the analysis of the post-baseline responses, allowing different regression slopes. We will use simulations to evaluate the approaches based on the bias and the coverage accuracy of the confidence interval.
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