Tehran University of Medical Sciences Iranian Journal of Public Health 2251-6085 44 2 2015 02 15 297 8 Hua Zhang Dept. of Medical Insurance, School of Public Health, Southeast University, Nanjing, China. Jianqian Chao Dept. of Medical Insurance, School of Public Health, Southeast University, Nanjing, China. Xiyan Li Dept. of Epidemiology and Biostatistics, School of Public Health, Southeast University, Nanjing, China. Pei Liu Dept. of Epidemiology and Biostatistics, School of Public Health, Southeast University, Nanjing, China. 2015 10 14 No Abstract https://ijph.tums.ac.ir/index.php/ijph/article/view/3660 https://ijph.tums.ac.ir/index.php/ijph/article/download/3660/3335