1. Department of Preventive Medicine, Jeju National University School of Medicine, Jeju, Korea.
2. Department of Epidemiology & Statistics, Jilin University School of Public Health Science, Changchun, China.
3. Department of Social & Preventive Medicine, Sungkyunkwan University School of Medicine, Suwon, Korea.
4. Department of Social Medicine, Hallym University College of Medicine, Chuncheon, Korea.
5. Department of Preventive Medicine, University of Ulsan College of Medicine, Seoul, Korea.
6. Department of Preventive Medicine, Seoul National University College of Medicine, Seoul, Korea.