[1] ICO, Tobacco Control Unit, Barcelona, Spain
[2] Univ Barcelona, Dept Clin Sci, Sch Med, Barcelona, Spain
[3] Inst Invest Biomed Bellvitge IDIBELL, Canc Prevent & Control Grp, Barcelona, Spain
[4] Ist Ric Farmacol Mario Negri, Dept Epidemiol, Milan, Italy
[5] Univ Milan, Sch Med, Dept Occupat Med, Milan, Italy
[6] Tobacco Free Res Inst, Dublin, Ireland