[1] London Sch Hyg & Trop Med, Fac Epidemiol & Populat Hlth, London, England
[2] Univ Loughborough, Sch Sport Exercise & Hlth Sci, Ctr Global Hlth & Human Dev, Loughborough, Leics, England
[3] Univ Witwatersrand, MRC Wits Dev Pathways Hlth Res Unit, Johannesburg, South Africa
[4] Univ Hosp Bristol NHS Fdn Trust, NIHR Collaborat Leadership Appl Hlth Res & Care W, Bristol, Avon, England
[5] Univ Bristol, NIHR Hlth Protect Res Unit Evaluat Intervent, Bristol, Avon, England
[6] Univ Bristol, Sch Social & Community Med, Bristol, Avon, England