1. Department of Social and Preventive Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
2. Nicotine Addiction Research Group, University of Malaya Centre of Addiction Sciences, University of Malaya, Kuala Lumpur, Malaysia
3. Department of Psychological Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
4. Department of Psychology, University of Waterloo, Waterloo, ON, Canada
5. School of Public Health Sciences, University of Waterloo, Waterloo, ON, Canada
6. Ontario Institute for Cancer Research, Toronto, ON, Canada