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 blockâ€“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]; PÂ = 0.002), prolonged abstinence (41.5% vs. 26.9%; odds ratio, 1.97 [CI, 1.38 to 2.82]; PÂ = 0.001), and continuous abstinence (19.2% vs. 12.6%; odds ratio, 1.64 [CI, 1.04 to 2.60]; PÂ = 0.032) versus standard therapy. Extended therapy reduced the risk for lapse (hazard ratio, 0.77 [CI, 0.63 to 0.95]; PÂ = 0.013) and increased the chances of recovery from lapses (hazard ratio, 1.47 [CI, 1.17 to 1.84]; PÂ = 0.001). Time to relapse was slower with extended versus standard therapy (hazard ratio, 0.50 [CI, 0.35 to 0.73]; PÂ < 0.001). At week 52, extended therapy produced higher quit rates for prolonged abstinence only (PÂ = 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.