[1] Brighton & Sussex Med Sch, Dept Primary Care & Publ Hlth, Brighton, E Sussex, England
[2] Univ Southampton, Fac Med, Southampton, Hants, England
[3] Kings Coll London, Inst Psychiat Psychol & Neurosci, London, England
[4] Publ Hlth England, London, England
[5] London Sch Hyg & Trop Med, London, England