[1] Univ Coll London Great Ormond St Inst Child Hlth, Populat Policy & Practice Programme, London WC1N 1EH, England
[2] Univ Warwick, Warwick Med Sch, Coventry CV4 7HL, England
[3] UCL, London WC1E 6BT, England
[4] St Georges Univ London, Ctr Neonatal & Paediat Infect, London SW17 0RE, England
[5] London Sch Hyg & Trop Med, Infect Dis Epidemiol, London WC1E 7HT, England
[6] Kings Coll London, Dept Geog, Strand, London WC2R 2LS, England
[7] Univ Copenhagen, Danish Res Ctr Migrat Ethn & Hlth, Danish Res Ctr Migrat Ethn & Hlth MESU, Lister Farimagsgade 5, DK-1014 Kobenhavn K, Denmark
[8] Bartlett Univ Coll London, 1-19 Torrington Pl, London WC1E 7HB, England
[9] Univ Oxford, Nuffield Dept Populat Hlth, Natl Perinatal Epidemiol Unit, Old Rd Campus, Oxford OX3 7LF, England
[10] UCL, Royal Free Campus,Rowland Hill St, London NW33 2PF, England
[11] Univ Washington, Inst Hlth Metr & Evaluat, Seattle, WA 98195 USA
[12] UCL, Inst Hlth Informat, 222 Euston Rd, London NW1 2DA, England