Effectiveness of extended-duration transdermal nicotine therapy: a randomized trial.

BACKGROUND Tobacco dependence is a chronic, relapsing condition that may require extended treatment. OBJECTIVE To assess whether extended-duration transdermal nicotine therapy increases abstinence from tobacco more than standard-duration therapy in adult smokers. DESIGN Parallel randomized, placebo-controlled trial from September 2004 to February 2008. Participants and all research personnel except the database manager were blinded to randomization. (ClinicalTrials.gov registration number: NCT00364156) SETTING Academic center. PARTICIPANTS 568 adult smokers. INTERVENTION In an unstratified small block-randomization scheme, participants were randomly assigned to standard therapy (Nicoderm CQ [GlaxoSmithKline, Research Triangle Park, North Carolina], 21 mg, for 8 weeks and placebo for 16 weeks) or extended therapy (Nicoderm CQ, 21 mg, for 24 weeks). MEASUREMENTS The primary outcome was biochemically confirmed point-prevalence abstinence at weeks 24 and 52. Secondary outcomes were continuous and prolonged abstinence, lapse and recovery events, cost per additional quitter, and side effects and adherence. RESULTS At week 24, extended therapy produced higher rates of point-prevalence abstinence (31.6% vs. 20.3%; odds ratio, 1.81 [95% CI, 1.23 to 2.66]; P = 0.002), prolonged abstinence (41.5% vs. 26.9%; odds ratio, 1.97 [CI, 1.38 to 2.82]; P = 0.001), and continuous abstinence (19.2% vs. 12.6%; odds ratio, 1.64 [CI, 1.04 to 2.60]; P = 0.032) versus standard therapy. Extended therapy reduced the risk for lapse (hazard ratio, 0.77 [CI, 0.63 to 0.95]; P = 0.013) and increased the chances of recovery from lapses (hazard ratio, 1.47 [CI, 1.17 to 1.84]; P = 0.001). Time to relapse was slower with extended versus standard therapy (hazard ratio, 0.50 [CI, 0.35 to 0.73]; P < 0.001). At week 52, extended therapy produced higher quit rates for prolonged abstinence only (P = 0.027). No differences in side effects and adverse events between groups were found at the extended-treatment assessment. LIMITATION The generalizability of the findings may be limited because participants were smokers without medical comorbid conditions who were seeking treatment, and differences in adherence across treatment groups were detected. CONCLUSION Transdermal nicotine for 24 weeks increased biochemically confirmed point-prevalence abstinence and continuous abstinence at week 24, reduced the risk for smoking lapses, and increased the likelihood of recovery to abstinence after a lapse compared with 8 weeks of transdermal nicotine therapy. PRIMARY FUNDING SOURCE National Institutes of Health.