Participants were eligible to participate if they were 18 years of age or older, smoked 10 or more cigarettes per day, and were motivated to quit smoking. Prior to randomization, participants completed baseline assessments of demographics, smoking history (including cigarettes smoked per day), and tobacco dependence including the Fagerström Test for Nicotine Dependence (FTND) (32). Participants provided a breath sample for alveolar carbon monoxide (CO) analysis to verify their smoking status and estimate their smoking heaviness.
