[1] Tsinghua Univ, Vanke Sch Publ Hlth, Beijing, Peoples R China
[2] Univ Cambridge, Dept Publ Hlth & Primary Care, Cambridge, England
[3] Duke Univ, Duke Global Hlth Inst, Durham, NC USA
[4] Aga Khan Univ, Dept Paediat & Child Hlth, Karachi, Pakistan
[5] Tsinghua Univ, Inst Hlth China, Beijing, Peoples R China