1. South African Medical Research Council; Environment and Health Research Unit; Durban South Africa
2. Karolinska Institutet; Integrative Health Care, Division of Nursing, Department of Neurobiology, Care Sciences and Society; Huddinge Sweden
3. Karolinska Institutet; Center for Social Sustainability, Department of Neurobiology, Care Sciences and Society; Huddinge Sweden
4. South African Medical Research Council; Biostatistics Unit; 491 Ridge Road, Overport Durban Kwazulu-Natal South Africa 4001
5. South African Medical Research Council; Cochrane South Africa; PO Box 19070 Tygerberg Cape Town Western Cape South Africa 7505