[1] Sichuan Univ, West China Sch Publ Hlth, Dept Hlth Related Behav & Social Med, Chengdu, Peoples R China
[2] Sichuan Univ, West China Hosp 4, Chengdu, Peoples R China
[3] Gansu Prov Matern & Child Care Hosp, Lanzhou, Peoples R China
[4] Sichuan Univ, West China Univ Hosp 2, West China Womens & Childrens Hosp, Chengdu, Peoples R China
[5] Univ S Florida, Sch Aging Studies, Coll Behav Community Sci, Tampa, FL 33620 USA