On November 22, 2019, we released our fifth short video, Alternative Randomization Ratios. This topic is presented by Dr. Mark FItzgerald of Berry Consultants, LLC. 


Most clinical trials are randomized 1:1, with equal allocation to the control and treatment arms. While 1:1 allocation typically minimizes the trial sample size, many trials use alternative ratios (often 2:1). These alternative ratios may increase the accrual rate, increase the size of the trial safety database, or address factors such as the incorporation of historical information. In this video Mark Fitzgerald discusses the pros and cons of differing allocation ratios and how a particular ratio might be chosen in practice.


Mark Fitzgerald earned his PhD in statistics from Carnegie Mellon University in 1996, and has since worked at Los Alamos National Laboratory, University of Colorado at Denver, and Neptune and Company. He has broad experience with statistical and mathematical modeling in a wide range of scientific disciplines. He has contributed to papers across disciplines with his many collaborators, as well as serving as Associate Editor for the Journal of Computational and Graphical Statistics.