3. Statistical analysis Collect and statistical analyses were performed using the SPSS 19.0 statistical software. An initial descriptive analysis involved an examination of the demographic, smoking, and clinical characteristics of the two treatment groups. The primary data analysis examined point prevalence smoking abstinence at 24 weeks. All analyses were intention-to-treat adjusted on the significantly differences between the two arms. Similar to other smoking cessation trials, our analyses assumed that patients who withdrew from the study returned to smoking at their baseline rate. Discrete data are described using proportions, and continuous data are described using means and standard deviations or, in the presence of skewed distributions, medians and interquartile ranges. The data analysis examined point prevalence smoking abstinence at 24 weeks with a comparison between the two treatment groups using 95% CIs based on the binomial distribution. Binary logistic regression was used to determine the factors that were independent predictors of success smoking cessation. Variables included in the multivariate analysis were selected at the significance level of 20 % in the univariate analysis. A p value of 5 % was considered statistically significant.