Jekel's epidemiology, biostatistics, preventive medicine, and public health / Joann G. Elmore, MD, MPH, Professor of Medicine, The Rosalinde and Arthur Gilbert Foundation Endowed, Chair in Health Care Delivery, David Geffen School of Medicine at UCLA, Professor of Health Policy and Management, UCLA Fielding School of Public Health, Director, UCLA National Clinician Scholars Program, Los Angeles, California, Dorothea M.G. Wild, MD, MPH, Research Affiliate, Institute of General Practice and Family Medicine, University of Bonn, Bonn, Germany, Heidi D. Nelson, MD, MPH, MACP, FRCP, Professor, Medical Informatics and Clinical Epidemiology and Medicine, Director, Scholarly Projects, School of Medicine, Oregon Health & Science University, Portland, Oregon, David L. Katz, MD, MPH, President, True Health Initiative, Founding Director, Preservation Research Center, Yale University/Griffin Hospital, New Haven, Connecticut.