1. Division of Community Pediatrics, Department of Pediatrics, School of Clinical Medicine, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
2. School of Clinical Medicine, Department of Family Medicine and Primary Care, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
3. School of Oral Health Sciences, Department of Community Dentistry, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
4. Centre for Health Sciences Education, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa