1. School of Public Health Shanxi Medical University Taiyuan China
2. Department of Prevention and Health Care Affiliated Heping Hospital of Changzhi Medical College Changzhi China
3. Department of Public Health and Preventive Medicine Changzhi Medical College Changzhi China
4. School of Medical Board Shanxi Datong University Datong China
5. The George Institute for Global Health University of New South Wales Sydney Australia
6. School of Public Health Harbin Medical University Harbin China