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Procedures with Unequally Sized Stages

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Group Sequential and Confirmatory Adaptive Designs in Clinical Trials

Part of the book series: Springer Series in Pharmaceutical Statistics ((SSPS))

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Abstract

In this chapter, we present group sequential test procedures that are specifically designed for unequally sized stages. We first describe the effect of using the decision boundaries designed for equally sized stages to the more general case of unequally sized stages. We also briefly describe a worst case scenario adjustment procedure. We then sketch the use of designs with prefixed sample sizes that need not to be equal to each other. A more general approach is provided by the use of the α-spending function or use function approach. This more sophisticated approach can handle unpredictable sample sizes per stage and we will see that even the maximum number of stages, K, need not be fixed in advance when using this approach. The extension to the β-spending function approach is also briefly discussed.

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Authors and Affiliations

  1. University of Cologne, Cologne, Germany

    Gernot Wassmer

  2. University of Bremen, Bremen, Germany

    Werner Brannath

Authors
  1. Gernot Wassmer
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  2. Werner Brannath
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Wassmer, G., Brannath, W. (2016). Procedures with Unequally Sized Stages. In: Group Sequential and Confirmatory Adaptive Designs in Clinical Trials. Springer Series in Pharmaceutical Statistics. Springer, Cham. https://doi.org/10.1007/978-3-319-32562-0_3

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