1. Chronic Disease Initiative in Africa, Division of Diabetic Medicine and Endocrinology Department of Medicine, University of Cape Town, Cape Town, South Africa
2. Department of Statistical Sciences, University of Cape Town, Cape Town, South Africa
3. Albertina & Walter Sisulu Institute of Ageing in Africa, Division of Geriatric Medicine, Department of Medicine, University of Cape Town, Cape Town, South Africa
4. WHO Study on global AGEing and adult health (SAGE), Geneva, Switzerland
5. Research Centre for Generational Health and Ageing, University of Newcastle, Newcastle, NSW, Australia
6. Office of the Deputy Vice Chancellor, Research and Innovation, North West University, Potchefstroom, South Africa
7. HIV/AIDS/STI/TB Research Programme, Human Sciences Research Council, Pretoria, South Africa