Multiplicity Adjustment Big and Small in Clinical Studies

Multiplicity adjustment in testing multiple statistical hypotheses is an important issue in clinical studies. This paper aims to clarify the issues in clinical pharmacology and therapeutics, using the testing of multiple efficacy end points as an example of testing a small to moderate number of hypotheses and the testing of biomarkers in genome-wide association studies (GWASs) as an example of testing a large number of hypotheses.