1. Department of Family and Community Medicine College of Medicine, University of Arizona Tucson AZ, USA
2. Department of Epidemiology and Biostatistics Mel and Enid Zuckerman College of Public Health, University of Arizona Tucson AZ, USA
3. Oklahoma Tobacco Research Center, Stephenson Cancer Center University of Oklahoma Health Sciences Center Oklahoma City OK USA
4. Department of Family Medicine and Community Health Medical School, University of Minnesota Minneapolis MN, USA
5. Division of Social and Behavioral Sciences School of Public Health, University of Memphis Memphis TN, USA
6. Department of Family Medicine and Biobehavioral Health Medical School, University of Minnesota Duluth MN USA