[1] Duke Univ, Trinity Coll Arts & Sci, Durham, NC 27708 USA
[2] Capital Med Univ, Dept Neurol, Beijing Tiantan Hosp, Beijing, Peoples R China
[3] Univ Oxford, Inst Social & Cultural Anthropol, Beijing, Peoples R China
[4] Stanford Univ, Stanford Prevent Res Ctr, Sch Med, Palo Alto, CA 94304 USA
[5] Harvard Univ, Harvard TH Chan Sch Publ Hlth, Boston, MA 02115 USA
[6] Duke Univ, Social Sci Res Inst, Durham, NC 27708 USA
[7] China Natl Clin Res Ctr Neurol Dis NCRC ND, Beijing, Peoples R China
[8] Duke Univ, Dept Orthopaed, Sch Med, Durham, NC 27708 USA
[9] Duke Univ, Duke Global Hlth Inst, Durham, NC 27708 USA
[10] Duke Univ, Duke Margolis Ctr Hlth Policy, Durham, NC 27708 USA