1. African Society for Laboratory Medicine , Johannesburg , South Africa
2. Division of Epidemiology and Biostatistics, Department of Global Health, Stellenbosch University , Cape Town , South Africa
3. Division of Chemical Pathology, Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg Hospital , Cape Town , South Africa
4. Division of Chemical Pathology, National Health Laboratory Service, Tygerberg Hospital , Cape Town , South Africa