1. Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts2Harvard Medical School, Boston, Massachusetts
2. Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts2Harvard Medical School, Boston, Massachusetts3Department of Anesthesiology, Critical Care, and Pain Medicine, Massachusetts
3. Department of Pediatrics, University of California, San Diego, La Jolla
4. Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts
5. Department of Epidemiology, Harvard T. H. Chan School of Public Health, Boston, Massachusetts