Group Sequential Methods for Clinical Trials with a One-Sided Hypothesis
Pocock提出的组序贯方法原本用于双侧检验，本文针对单侧假设的临床试验，提出了三种修改方案，避免因继续试验判断新疗法是否劣于标准疗法而引发伦理问题。
Pocock (1977) has recently proposed group sequential methods for sequential analysis of clinical trials. However, these methods are intended to test a null hypothesis against a two-sided alternative, and many trials of a new therapy against a standard have one-sided alternatives. Continuation of the trial to determine whether the new therapy is actually inferior to the standard therapy may be inappropriate or even unethical. In the present paper, three possible modifications of the group sequential method for sequential monitoring of clinical trials testing a one-sided hypothesis are considered.