1. The First Affiliated Hospital of Harbin Medical University, No. 199 Dongdazhi Street, Nangang District, Harbin, Heilongjiang 150001, China
2. Public Health School, Mudanjiang Medical College, No. 3 Tongxiang Street, Aimin District, Mudanjiang, Heilongjiang 157011, China
3. The Third Affiliated Hospital of Harbin Medical University, No. 150 Haping Road, Nangang District, Harbin, Heilongjiang 150081, China
4. Public Health School, Harbin Medical University, No. 157 Baojian Road, Nangang District, Harbin, Heilongjiang 150081, China