1. University of Tsukuba; Center for Global Health, Mito Kyodo General Hospital; 3-2-7, Miyamachi Mito Ibaraki Japan 310-0015
2. Kyoto University School of Public Health; Department of Health Informatics; Yoshida Konoecho, Sakyo-ku Kyoto Japan 606-8501
3. Khon Kaen University; Department of Biostatistics and Demography, Faculty of Public Health; 123 Mitraparb Road Amphur Muang Khon Kaen Thailand 40002
4. Jichi Medical University; Department of Obstetrics and Gynecology; 3311-1 Yakushiji Shimotsuke Tochigi Japan 329-0431
5. National Center for Child Health and Development; Department of Health Policy; 2-10-1 Okura Setagaya-ku Tokyo Tokyo Japan 166-0014