1. Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, and Clinician Scientist Training Program, Department of Medicine, University of Toronto, Toronto, Ontario, Canada (M.F.)
2. Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts (S.C.K., S.S., D.K., E.P.)
3. Sunnybrook Hospital and University of Toronto, Toronto, Ontario, Canada (D.A.R.)