M C Schneeweiss1,2,3, L Perez Chada1,3, A B Gottlieb4, J F Merola1,5,3. 1. Department of Dermatology, Brigham and Women's Hospital, Boston, MA, USA. 2. Department of Medicine, Division of Pharmacoepidemiology, Brigham and Women's Hospital, Boston, MA, USA. 3. Harvard Medical School, Boston, MA, USA. 4. Department of Dermatology, Icahn School of Medicine at Mount Sinai, New York, NY, USA. 5. Department of Medicine, Division of Rheumatology, Brigham and Women's Hospital, Boston, MA.