Vincent Lo Re1, Olaf H Klungel2, K Arnold Chan3, Catherine A Panozzo4, Wei Zhou5, Almut G Winterstein6. 1. Center for Pharmacoepidemiology Research and Training, Center for Clinical Epidemiology and Biostatistics, and Division of Infectious Diseases, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA. 2. Division of Pharmacoepidemiology and Clinical Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, Netherlands. 3. College of Medicine, National Taiwan University, Taipei, Taiwan. 4. Department of Population Medicine, Harvard Pilgrim Health Care Institute, Harvard Medical School, Boston, Massachusetts, USA. 5. Department of Epidemiology, Merck & Co, West Point, Pennsylvania, USA. 6. Center for Drug Evaluation and Safety, Department of Pharmaceutical Outcomes and Policy, College of Pharmacy, and Department of Epidemiology, College of Medicine and Health and Health Professions, University of Florida, Gainesville, Florida, USA almut@cop.ufl.edu.