1 Department of Biostatistics, Harvard TH Chan School of Public Health, Boston, MA 02115, USA.
2 Division of Biometrics V, Office of Biostatistics, Office of Translational Sciences, Center for Drug Evaluation and Research, Food and Drug Administration, Silver Spring, MD, USA.
3 Pfizer Inc, Groton, CT, USA.
4 Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital, Boston, MA, USA.
5 Department of Biostatistics, Harvard TH Chan School of Public Health, Boston, MA 02115, USA. Electronic address: wei@hsph.harvard.edu.