1. Epidemiology; Pfizer Inc.; Collegeville PA USA
2. Clinical Epidemiology and Biostatistics; Perelman School of Medicine, University of Pennsylvania; Philadelphia PA USA
3. Center for Pharmacoepidemiology Research and Training (CPeRT); University of Pennsylvania; Philadelphia PA USA
4. Division of Infectious Diseases, Department of Medicine; University of Pennsylvania; Philadelphia PA USA
5. Department of Statistics, Wharton School; University of Pennsylvania; Philadelphia PA USA