1. Burden of Disease Research Unit, South African Medical Research Council, Cape Town, South Africa
2. School of Nursing and Public Health Medicine, University of KwaZulu-Natal, Durban, South Africa
3. School of Public Health, University of the Western Cape, Bellville, South Africa
4. School of Public Health and Family Medicine, University of Cape Town, Cape Town, South Africa
5. Division of Health Systems and Public Health, Stellenbosch University, Cape Town, South Africa