No statistically significant differences were obtained with biochemically confirmed point prevalence abstinence at 23-weekfollow-up or with prolonged abstinence assessed at weeks 23or 52. These findings do not support recommendations thatcombination therapy with varenicline plus the nicotine patchbe used in clinical care or that extended duration vareniclinetherapy be used during quit attempts.The standard 12-week varenicline monotherapy used inthis study did not have an exceptionally high abstinence rate,and thus likely did not produce a ceiling effect.