[1] Univ Sao Paulo, Sch Med, Dept Prevent Med, BR-01246903 Sao Paulo, SP, Brazil
[2] Univ Estado Rio De Janeiro, Inst Social Med, Rio De Janeiro, RJ, Brazil
[3] Univ Fed Goias, Inst Trop Pathol & Publ Hlth, Dept Collect Hlth, Goiania, Go, Brazil
[4] Leonor Mendes de Barms Matern Hosp, Hlth State Secretariat, Sao Paulo, SP, Brazil
[5] Univ Sao Paulo, Sch Med, Hosp Clin, Clin Infect & Parasit Dis, BR-05403000 Sao Paulo, Brazil
[6] London Sch Hyg & Trop Med, Dept Hlth Serv Res & Policy, London WC1, England
[7] Harvard Univ, Sch Publ Hlth, Dept Hlth Policy & Management, Ctr Hlth Decis Sci, Boston, MA 02115 USA