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Blinded Sample Size Reestimation in Multiarmed Clinical Trials

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Abstract

For fixed sample size designs, there is a risk that expected trial outcomes may not obtain adequate power because there is usually some uncertainty about the variance of the outcome variable in the planning phase. This deficit can be remedied by reestimating the variance during the ongoing trial and modifying the initially planned sample size if necessary. From a regulatory view, any adjustment to sample size should occur without unblinding the treatment group membership of the data. Corresponding methods proposed until now are restricted to studies comparing two treatment groups. We present sample size recalculation procedures for multiarmed trials and compare their performance by Monte Carlo simulations.

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Authors and Affiliations

  1. Dr. Willmar Schwabe Pharmaceuticals, P.O. Box 410925, D-76209, Karlsruhe, Germany

    Meinhard Kieser PhD (Head Biometrics)

  2. Department of Medical Biometry, University of Heidelberg, Heidelberg, Germany

    Tim Friede MSc (Research Assistant)

Authors
  1. Meinhard Kieser PhD
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  2. Tim Friede MSc
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Correspondence to Meinhard Kieser PhD.

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Kieser, M., Friede, T. Blinded Sample Size Reestimation in Multiarmed Clinical Trials. Ther Innov Regul Sci 34, 455–460 (2000). https://doi.org/10.1177/009286150003400214

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  • DOI: https://doi.org/10.1177/009286150003400214

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