[1] Harvard Univ, Sch Publ Hlth, Dept Populat & Int Hlth, Boston, MA 02115 USA
[2] Harvard Univ, Sch Publ Hlth, Harvard Ctr Populat & Dev Studies, Cambridge, MA 02138 USA
[3] Erasmus MC, Inst Med Technol Assessment, Rotterdam, Netherlands
[4] WHO, Strateg Informat & Res, Dept HIV AIDS, CH-1211 Geneva, Switzerland
[5] WHO, Costs Effectiveness Expenditure & Prior Setting T, Hlth Syst Financing Dept, CH-1211 Geneva, Switzerland