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Activity Number:
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337
- Interim Monitoring and Analyses: Two-Stage, Multi-Stage, and Group Sequential Designs
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Type:
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Contributed
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Date/Time:
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Tuesday, August 1, 2017 : 10:30 AM to 12:20 PM
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Sponsor:
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Biopharmaceutical Section
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Abstract #324807
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View Presentation
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Title:
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Robust Inference for Group Sequential Trials
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Author(s):
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Jitendra Ganju* and Yunzhi Lin and Kefei Zhou
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Companies:
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and AbbVie and Theravance
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Keywords:
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interim analyses ;
group sequential trials ;
permutation methods
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Abstract:
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For ethical reasons group sequential trials were introduced to allow trials to stop early in the event of extreme results. For a given endpoint the norm is to use a single test statistic, and to use that same statistic for each analysis. This approach is risky because there is loss in power if the assumptions that ensure optimality for each analysis are not met. To minimize the risk of moderate to substantial loss in power due to a suboptimal choice of a statistic, a robust method was developed for non-sequential trials. This talk evaluates the performance of two p-value combining methods for group sequential trials. The gain or loss in power with the combination method relative to a single statistic is asymmetric in its favor. Depending on the power of each individual test, the combination method can give more power than any single test or give power that is closer to the test with the most power. The versatility of the method is that it can combine p-values from different test statistics for analysis at different times. The robustness of results suggests that inference from group sequential trials can be strengthened with use of combined tests.
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Authors who are presenting talks have a * after their name.
