[1] Capital Inst Pediat, Dept Epidemiol, Yabao Rd,Chaoyang Dist 2, Beijing 100020, Peoples R China
[2] Chinese Ctr Dis Control & Prevent China CDC, Ctr Publ Hlth Surveillance & Informat Serv, Beijing, Peoples R China
[3] Jining Med Univ, Sch Publ Hlth, Jining, Shandong, Peoples R China
[4] Karolinska Inst, Aging Res Ctr, Dept Neurobiol Care Sci & Soc, Stockholm, Sweden