Figure 2.

Point-in-time smoking abstinence at the 14 assessment visits, by study group. Note: We defined point-in-time smoking abstinence as an exhaled carbon monoxide (CO) level <8 parts per million. Abstinence percentages shown in this figure are based on the assumption that individuals with missing CO data were nonabstinent. We assessed the overall, time-averaged difference in abstinence between the study groups using repeated-measures logistic regression with generalized estimating equations.