1. LWNdaba,MBChB,FCP(SA),DipIntMed(SA),DipHIV(SA),PGDipRenalMed (UK) ORCID for author Ndaba: https://orcid.org/0000-0002-2605-8134
2. Registrar, Department of Internal Medicine, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa ndabalw@gmail.com
3. S A van Blydenstein, MB BCh, DCH, MMed (Int Med), FCP (SA), Cert Pulm (SA) Department of Internal Medicine, Chris Hani Baragwanath Academic Hospital, Johannesburg, South Africa
4. K E Hodkinson, MB BCh, MMed (Haem), FCPath (Haem) Department of Molecular Medicine and Haematology, Faculty of Health Sciences, University of the Witwatersrand and National Health Laboratory Service, Johannesburg, South Africa
5. Previtali E, Bucciarelli P, Passamonti SM, Martinelli I. Risk factors for venous and arterial thrombosis. Blood Transfus 2011;9(2):120-138. https://doi. org/10.2450/2010.0066-10