1. Division of Pharmacoepidemiology and Pharmacoeconomics; Department of Medicine, Brigham and Women's Hospital and Harvard Medical School; Boston Massachusetts USA
2. Center for Pharmacoepidemiology Research and Training; Center for Clinical Epidemiology and Biostatistics, and Department of Biostatistics and Epidemiology, University of Pennsylvania Perelman School of Medicine; Philadelphia Pennsylvania USA
3. Department of Epidemiology; University of Iowa College of Public Health; Iowa City Iowa USA
4. Department of Population Medicine; Harvard Medical School and Harvard Pilgrim Health Care Institute; Boston Massachusetts USA
5. Office of Medical Policy; Center for Drug Evaluation and Research, Food and Drug Administration; Silver Spring Maryland USA
6. Division of Epidemiology; Office of Surveillance and Epidemiology, Center for Drug Evaluation and Research, Food and Drug Administration; Silver Spring Maryland USA