[1] Queen Mary Univ London, William Harvey Res Inst, London E1 4NS, England
[2] Univ Southampton, Sch Primary Care Populat Sci & Med Educ, Southampton, Hants, England
[3] Univ Oxford, Nuffield Dept Primary Care Hlth Sci, Oxford, England
[4] Univ Western Australia, Perth, WA, Australia
[5] London Sch Hyg & Trop Med, London, England
[6] UCL, London, England
[7] Univ Calif San Diego, San Diego, CA 92103 USA
[8] Univ Cambridge, Dept Math, Cambridge, England
[9] Princeton Univ, Inst Adv Study, Princeton, NJ 08544 USA
[10] Univ St Andrews, Edinburgh, Midlothian, Scotland
[11] Univ Cambridge, Dept Psychiat, Cambridge, England