Chang Mark
Millennium Pharmaceuticals Inc., Cambridge, MA 02139, USA.
Pharm Stat. 2007 Jan-Mar;6(1):43-52. doi: 10.1002/pst.242.
Multiple-arm dose-response superiority trials are widely studied for continuous and binary endpoints, while non-inferiority designs have been studied recently in two-arm trials. In this paper, a unified asymptotic formulation of a sample size calculation for k-arm (k>0) trials with different endpoints (continuous, binary and survival endpoints) is derived for both superiority and non-inferiority designs. The proposed method covers the sample size calculation for single-arm and k-arm (k> or =2) designs with survival endpoints, which has not been covered in the statistic literature. A simple, closed form for power and sample size calculations is derived from a contrast test. Application examples are provided. The effect of the contrasts on the power is discussed, and a SAS program for sample size calculation is provided and ready to use.
多臂剂量反应优效性试验针对连续和二元终点进行了广泛研究，而非劣效性设计最近在双臂试验中得到了研究。本文针对优效性设计和非劣效性设计，推导了具有不同终点（连续、二元和生存终点）的k臂（k>0）试验样本量计算的统一渐近公式。所提出的方法涵盖了具有生存终点的单臂和k臂（k≥2）设计的样本量计算，而这在统计学文献中尚未涉及。通过对比检验推导出了用于功效和样本量计算的简单封闭形式。提供了应用示例。讨论了对比对功效的影响，并提供了一个可供直接使用的用于样本量计算的SAS程序。
