Abstract
Despite best efforts, some crucial information used to design a confirmatory trial may not be available, or may be available but with a high degree of uncertainty, at the design stage. When this happens, it may be prudent to check the validity of those assumptions using interim data from the study and make midcourse ad¬justment if necessary. One such adjustment is to modify the sample size. In this article, we focus on sample size reestimation (SSR) for phase III and IV studies. The discussion is rel¬evant to both continuous and binary end-points even though the basis for SSR might differ for those two cases. We review common¬ly used approaches to adjust sample size and provide recommendations on how SSR should be implemented to achieve the objectives and maintain the integrity of the trial. The recom¬mendations cover scientific, procedural, and logistic considerations.
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Chuang-Stein, C., Anderson, K., Gallo, P. et al. Sample Size Reestimation: A Review and Recommendations. Ther Innov Regul Sci 40, 475–484 (2006). https://doi.org/10.1177/216847900604000413
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DOI: https://doi.org/10.1177/216847900604000413