Guo Helen Y, Liu Aiyi
Thomas Jefferson High School for Science and Technology, Alexandria, Virginia, USA.
J Biopharm Stat. 2005;15(5):773-81. doi: 10.1081/BIP-200067771.
A phase II clinical trial evaluating the rate of response of a new therapeutic treatment is often designed to have one or two interim analyses, allowing possible termination of the trial at an early stage if lack of treatment efficacy is evident. Due to the sequential nature of such a trial, the sample proportion yields biased estimation for the rate of response. In this paper we propose an estimator of response rate by subtracting the estimated bias directly from the sample proportion. The proposed estimator is simple, intuitive, and easy to compute. When the bias of the sample proportion is of concern to the investigators, the proposed estimator is an efficient alternative to other estimators in the literature in terms of bias and mean squared error.
一项评估新型治疗方法反应率的II期临床试验通常设计为进行一到两次中期分析，以便在明显缺乏治疗效果时能够在早期阶段终止试验。由于此类试验的序贯性质，样本比例会对反应率产生有偏估计。在本文中，我们提出了一种通过直接从样本比例中减去估计偏差来估计反应率的方法。所提出的估计器简单、直观且易于计算。当样本比例的偏差受到研究人员关注时，就偏差和均方误差而言，所提出的估计器是文献中其他估计器的有效替代方法。
