1 Department of Public Health Medicine, Faculty of Medicine, and Health Services Research and Development Center, University of Tsukuba, Tsukuba, Japan.
2 Epidemiology and Prevention Group, Center for Public Health Sciences, National Cancer Center, Tokyo, Japan.
3 Department of Public Health Medicine, Faculty of Medicine, and Health Services Research and Development Center, University of Tsukuba, Tsukuba, Japan. k-yamagishi@umin.net.
4 Ibaraki Western Medical Center, Chikusei, Japan. k-yamagishi@umin.net.
5 Public Health, Department of Social Medicine, Osaka University Graduate School of Medicine, Suita, Japan.