Statistical Approaches to Multiplicity Issues in Clinical Trials

This paper discusses various multiplicity issues arisen in clinical trials and possible statistical approaches to these issues. We especially stress the importance of the closed testing procedures (CTPs) in the setting of clinical trials: They include various modified Bonferroni procedures, e.g., step-down Dunnett procedure, hierarchical procedure, and Williams test. Moreover they can be even applied to adaptive designs in clinical trials. We illustrate the basic CTP procedures in detail.