1. Faculty of Health Sciences; University of the Witwatersrand, Charlotte Maxeke Johannesburg Academic Hospital; Johannesburg South Africa
2. Division of Epidemiology and Biostatistics; School of Public Health, University of the Witwatersrand; Johannesburg South Africa
3. Faculty of Health Sciences; University of the Witwatersrand, Chris Hani Baragwanath Academic Hospital; Johannesburg South Africa
4. Faculty of Economics; University of Cape Town; Cape Town South Africa
5. Faculty of Health Sciences; University of Pretoria, Steve Biko Academic Hospital; Pretoria South Africa
6. Faculty of Health Sciences; University of the Free State, Universitas Hospital; Bloemfontein South Africa
7. Faculty of Health Sciences; University of Kwazulu-Natal, Inkosi Albert Luthuli Hospital; Durban South Africa
8. South African Medical Research Council; Parow South Africa
9. Faculty of Health Sciences; University of Stellenbosch, Tygerberg Hospital; Tygerberg South Africa
10. Divison of Paediatric Haemetology and Oncology; Frere Hospital; East London South Africa
11. Divison of Paediatric Haemetology and Oncology; Polokwane-Mankweng Hospital Complex; Polokwane South Africa
12. Netcare Parklands Hospital; Durban South Africa
13. Faculty of Health Sciences; University of Cape Town, Red Cross War Memorial Children's Hospital; Cape Town South Africa