[1] Brigham & Womens Hosp, Boston, MA 02115 USA
[2] Harvard Med Sch, Massachusetts Gen Hosp, Dept Med, Boston, MA 02115 USA
[3] Harvard Med Sch, Brigham & Womens Hosp, Dept Med, Div Pharmacoepidemiol & Pharmacoecon, Boston, MA 02115 USA
[4] Brigham & Womens Hosp, Div Pharmacoepidemiol & Pharmacoecon, Boston, MA 02115 USA
[5] Brigham & Womens Hosp, Dept Med, Div Pharmacoepidemiol & Pharmacoecon, 75 Francis St, Boston, MA 02115 USA
[6] Harvard Med Sch, Boston, MA 02115 USA