Abstract
BACKGROUND: Limited treatment options exist for smokers who are not ready to make a quit attempt. Smoking reduction may be a viable treatment approach if proven to increase the rates of long-term abstinence from smoking. METHOD: A systematic review of randomized, controlled trials that tested smoking-reduction interventions (pharmacological, behavioral, or both combined) among smokers who were not ready to make a quit attempt (immediately or in the next month) was conducted to assess the efficacy of these strategies in promoting future smoking abstinence. The primary outcome was the 7-day point-prevalence smoking abstinence at longest follow-up (≥6months). Ten trials were included; six tested pharmacologic interventions, one evaluated a behavioral intervention, and three evaluated combined interventions. RESULTS: Pharmacologic (2732 participants; OR 2.33, 95% CI 1.43 to 3.79) and combined (638 participants; OR 2.14, 95% CI: 1.28 to 3.60) smoking-reduction interventions significantly increased long-term abstinence from smoking. Insufficient evidence was available on the efficacy of behavioral smoking-reduction interventions (320 participants; OR 1.49, 95% CI 0.56 to 3.93). CONCLUSIONS: Further research to evaluate the efficacy of smoking reduction should have cessation as an endpoint, focus on clarity and consistency in patient selection, and identify the mechanism through which nicotine replacement therapy assisted smoking reduction in increasing abstinence rates.