General characteristics of ECLAT study sample at baseline.

Legend: SD – standard deviation; IQR – interquartile range; Pack/yrs – pack-years; Cig/day – Cigarettes smoked per day; eCO – exhaled carbon monoxide; FTND – Fagerstrom Test of Nicotine Dependence; GN-SBQ- Glover-Nilsson Smoking Behavioral Questionnaire; BDI – Beck Depression Inventory; BAI – Beck Anxiety Inventory. Data are reported for the overall sample and separately for each treatment group. Differences among groups were evaluated by χ2 test for categorical variables, one-way analysis of variance (ANOVA) and Fisher protected LSD for parametric variables, and Kruskal-Wallis test for non parametric variables. *p = 0.04 between A and C groups (ANOVA).