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Activity Number:
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115
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Type:
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Contributed
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Date/Time:
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Monday, August 3, 2009 : 8:30 AM to 10:20 AM
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Sponsor:
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WNAR
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| Abstract - #304574 |
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Title:
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Conditional Estimation After a Phase II Group Sequential Diagnostic Biomarker Study
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Author(s):
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Joseph S. Koopmeiners*+ and Ziding Feng
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Companies:
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University of Washington and Fred Hutchinson Cancer Research Center
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Address:
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, , ,
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Keywords:
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Abstract:
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The development of diagnostic biomarkers for disease screening is a five phase process. In phase II, performance of the biomarker is compared to established levels of performance to determine if further study is warranted. Most biomarkers identified in phase I will have inadequate performance. This motivates the use of group sequential designs that allow for early termination due to futility in phase II. An option for early termination will lead to biased estimates at study completion for studies that reach full enrollment. We propose conditional estimators and confidence intervals that correct for the bias caused by the option for early termination due to futility. The adjusted estimators and confidence intervals are used to estimate ROC(t) and PPV(v) after a two-stage group sequential trial that allows for early termination and their performance is evaluated by simulation.
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- The address information is for the authors that have a + after their name.
- Authors who are presenting talks have a * after their name.
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