1Division of Anatomical Pathology, Department of Pathology, Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg, South Africa
2Division of Chemical Pathology, Department of Pathology, Faculty of Medicine and Health Sciences, Stellenbosch University, National Health Laboratory Service, Tygerberg Hospital, Tygerberg, South Africa
3Paarl Medical Centre, Paarl, South Africa
4Centre for Statistical Consultation, Department of Statistics and Actuarial Sciences, University of Stellenbosch, Tygerberg, South Africa