Adaptive designs are playing an increasingly important role in the planning of clinical trials. While there exists various research on the optimal determination of a two‐stage design, non‐optimal versions still are frequently applied in clinical research. In this article, we strive to motivate the application of optimal adaptive designs and give guidance on how to determine them. It is demonstrated that optimizing a trial design with respect to particular objective criteria can have a substantial benefit over the application of conventional adaptive sample size recalculation rules. Furthermore, we show that in many practical situations, optimal group‐sequential designs show an almost negligible performance loss compared to optimal adaptive designs. Finally, we illustrate how optimal designs can be tailored to specific operational requirements by customizing the underlying optimization problem.

中文翻译：

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自适应两阶段设计的最佳计划

自适应设计在临床试验计划中发挥着越来越重要的作用。尽管存在关于优化两阶段设计的各种研究，但非最优版本仍然经常用于临床研究。在本文中，我们努力激发最佳自适应设计的应用，并为如何确定它们提供指导。事实证明，相对于特定的客观标准优化试验设计可以比传统的自适应样本大小重新计算规则的应用具有实质性的优势。此外，我们表明，在许多实际情况下，与最佳自适应设计相比，最佳群序设计的性能损失几乎可以忽略不计。最后，