1. Department of Community Medicine, Faculty of Medicine, Ramathibodi Hospital,, Rajdevi, Bangkok, Thailand
2. Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
3. Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
4. Epidemiology Unit, Faculty of Medicine, Prince of Songkla University, Songkhla, Thailand
5. National Health Examination Survey Office, Health System Research Institute, Nonthaburi, Thailand
6. Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
7. College of Public Health Sciences, Chulalongkorn University, Bangkok, Thailand