to model current daily (N = 816) vs. former (abstinence of ≥6 months; N = 833) smoking, and a mixed effects poisson regression was used to model smoking quantity among current smokers (quantitative CPD; N = 816). Odds ratios (ORs) obtained for current vs. former smoking depict whether it is more (OR>1) or less (OR<1) likely to fall into category of ‘former smoker’ as wGRS increases. Regression coefficients (betas) obtained for smoking quantity indicate the increase (positive beta) or decrease (negative beta) in CPD as wGRS increases. All analyses were adjusted for age, sex, and BMI, and families were assumed to form clusters in the NAG-FIN sample. Finally, a meta-analysis of the two samples was performed. Additionally, we utilized available questionnaire data of potential confounders of cessation. In a sensitivity analysis we excluded (i) 62 (7.4%) NAG-FIN former smokers who report quitting due to adverse health effects, and (ii) 188 (23%) current and 176 (21%) former smokers who reported having a DSM-IV (Diagnostic and Statistical Manual of Mental Disorders, 4th edition) major depressive disorder diagnosis. For FINRISK we excluded 820 (26%) current smokers and 775 (29%) former smokers who either (i) reported having a diagnosis of cancer of cardiovascular disease
