Department of Community Medicine, Faculty of Medicine Chiang Mai University, Chiang Mai 50200, Thailand.Department of Community Medicine, Faculty of Medicine Chiang Mai University, Chiang Mai 50200, Thailand.Department of Community Medicine, Faculty of Medicine Chiang Mai University, Chiang Mai 50200, Thailand.Department of Community Medicine, Faculty of Medicine Chiang Mai University, Chiang Mai 50200, Thailand.Department of Community Medicine, Faculty of Medicine Chiang Mai University, Chiang Mai 50200, Thailand.Department of Community Medicine, Faculty of Medicine Chiang Mai University, Chiang Mai 50200, Thailand.