1 Office of Pharmacovigilance I, Pharmaceuticals and Medical Devices Agency, Tokyo, Japan.
2 Office of Medical Informatics and Epidemiology, Pharmaceuticals and Medical Devices Agency, Tokyo, Japan.
3 Section of Clinical Epidemiology, Department of Data Science, Center for Clinical Science, National Center for Global Health and Medicine, 1-21-1, Toyama Shinjuku-ku, Tokyo, 162-8655, Japan. chishiguro@hosp.ncgm.go.jp.