1. Tobacco Control Unit Institut Català d'Oncologia (ICO) L'Hospitalet de Llobregat Barcelona Spain
2. Tobacco Control Research Group Institut d'Investigació Biomèdica de Bellvitge (IDIBELL) L'Hospitalet de Llobregat Barcelona Spain
3. School of Medicine and Health Sciences Campus of Bellvitge. University of Barcelona L'Hospitalet del Llobregat Barcelona Spain
4. Consortium for Biomedical Research in Respiratory Diseases (CIBER en Enfermedades Respiratorias, CIBERES) Madrid Spain
5. Philip R. Lee Institute for Health Policy Studies University of California San Francisco San Francisco CA USA