1. Department of Health Promotion, Education and Behavior, Arnold School of Public Health, University of South Carolina, Columbia, SC, USA
2. Departamento de Investigación sobre Tabaco, Instituto Nacional de Salud Pública, Cuernavaca, México
3. Department of Public Health Sciences, College of Health and Human Services, University of North Carolina, Charlotte, NC,USA
4. Department of Epidemiology and Biostatistics, Arnold School of Public Health, University of South Carolina, Columbia, SC, USA
5. Department of Epidemiology, School of Public Health, Center for Social Epidemiology and Population Health, University of Michigan, Ann Arbor, MI, USA