[1] George Washington Univ, Sch Publ Hlth, Milken Inst, Washington, DC 20052 USA
[2] Johns Hopkins Univ, Dept Int Hlth, Baltimore, MA USA
[3] Natl Inst Publ Hlth Mexico, Cuernavaca, Morelos, Mexico
[4] Imperial Coll London, George Inst Global Hlth, London, England
[5] Univ New South Wales, Sch Populat Hlth, Sydney, NSW, Australia