[1] Capital Med Univ, Sch Publ Hlth, Dept Epidemiol & Hlth Stat, Beijing, Peoples R China
[2] Capital Med Univ, Beijing Municipal Key Lab Clin Epidemiol, Beijing, Peoples R China
[3] Capital Med Univ, Beijing Tian tan Hosp, Dept Neurosurg, Beijing, Peoples R China
[4] Greenwood Med Co, Melbourne, Vic, Australia
[5] La Trobe Univ, Dept Math & Stat, Melbourne, Vic, Australia
[6] Edith Cowan Univ, Sch Med Sci & Hlth, Global Hlth & Genom, Perth, WA, Australia
[7] Capital Med Univ, Xuan Wu Hosp, Beijing Geriatr Healthcare Ctr, 45 Changchun St, Beijing 100053, Peoples R China