Roger J Lewis1, Karim A Calis2, David L DeMets3. 1. Department of Emergency Medicine, Harbor-UCLA Medical Center, Torrance, California2Berry Consultants LLC, Austin, Texas. 2. Office of Medical Policy, Center for Drug Evaluation and Research, US Food and Drug Administration, Silver Spring, Maryland4Office of the Clinical Director, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland. 3. Department of Biostatistics and Medical Informatics, University of Wisconsin, Madison.