1. Department of Public Health, School of Health Care Sciences, Sefako Makgatho Health Sciences University, Pretoria 0208, South Africa
2. Department of Community Dentistry, School of Dentistry, University of Pretoria, Pretoria 0208, South Africa
3. Non-Communicable Diseases Research Unit, South African Medical Research Council, Tygerberg, Cape Town 7505, South Africa
4. Department of Life and Consumer Sciences, College of Agriculture and Environmental Sciences, University of South Africa, Roodepoort, Johannesburg 1709, South Africa
5. Africa Centre for Tobacco Industry Monitoring and Policy Research (ATIM), School of Health Systems and Public Health, University of Pretoria, Pretoria 0028, South Africa