1. From the Departments of Clinical Epidemiology and Clinical Medicine (N.S., K.L., H.T.S.), Aarhus University; Department of Clinical Biochemistry (K.L.), Aarhus University Hospital, Denmark; Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine (J.C.L., E.P.), Brigham and Women's Hospital and Harvard Medical School, Boston, MA; and Yale School of Medicine (L.H.S.), New Haven, CT.