1. a London School of Hygiene & Tropical Medicine , London , UK
2. b University Teaching Hospital , Lusaka , Zambia
3. c Department of Psychiatry, National Mental Health Resource Centre , University of Zambia, School of Medicine , Lusaka , Zambia
4. d Centre for International Child Health , Institute of Child Health , London , UK
5. e Division of Health and Social Care Research , King's College LondonFlorence Nightingale School of Nursing and Midwifery , London , UK