1. University of California, San Francisco; Philip R. Lee Institute for Health Policy Studies; San Francisco CA USA
2. Tobacco Control Unit; Cancer Prevention and Control Department; Catalan Institute of Oncology, Institut d'Investigació Biomèdica de Bellvitge-IDIBELL; Barcelona Spain
3. Department of Social Welfare; Ewha Womans University; Seoul South Korea
4. Department of Psychiatry; University of California San Francisco; San Francisco CA USA