1. Department of Epidemiology, Infectious Disease Control and Prevention Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.
2. Project Research Center for Epidemiology and Prevention of viral hepatitis and hepatocellular carcinoma, Hiroshima University, Hiroshima, Japan.
3. Senogawa Hospital, Hiroshima, Japan.
4. KONUMA Memorial Institute of Addiction and Mental Health, Senogawa Hospital, Hiroshima, Japan.