School of Public Health Hainan Medical University Hainan Haikou 571199 China;
School of Public Health Hainan Medical University Hainan Haikou 571199 China;
School of Public Health Hainan Medical University Hainan Haikou 571199 China;
School of Public Health Hainan Medical University Hainan Haikou 571199 China;
School of Public Health Hainan Medical University Hainan Haikou 571199 China;
Hainan Health School Hainan Haikou 570311 China;