[Gao, Hong; Wu, Xinrui; Tan, Hongzhuan; Hu, Shimin; Tian, Zhengwen] Cent S Univ, Xiangya Sch Publ Hlth, Dept Epidemiol & Hlth Stat, 110 Xiangya Rd, Changsha 410008, Hunan, Peoples R China.
[Gao, Hong] Univ South China, Sch Nursing, Hengyang, Hunan, Peoples R China.
[Li, Yumei; Liu, Dong-e; Tang, Jing] Cent S Univ, Xiangya Hosp, Reprod Med Ctr, Changsha, Hunan, Peoples R China.