Nicotine replacement therapy to aid gradual cessation in smokers with no intention to quit: Association between reduction quantity and later abstinence

OBJECTIVE We examined how quantity and trajectory of smoking reduction influence later abstinence in smokers without intention to quit and being prescribed free nicotine replacement therapy (NRT). METHOD We conducted an a posteriori analysis from a data archive of adult smokers in a randomized controlled trial of smoking reduction using counseling and free NRT (n = 928). Reduction was analyzed as the absolute and percentage decrease in self-reported daily cigarette consumption at three follow-ups (1 week, 1 and 3 months) compared with the baseline. Logistic regression model and multiple imputation were used to examine the association between early reduction and abstinence at 6 months. RESULTS Reducing 10% of cigarette consumption at the three follow-ups was associated with 16% (95% CI 5-28%), 23% (95%CI 11-36%) and 27% (95% CI 13-42%) increase in abstinence, respectively. Greater reduction predicted abstinence when the percentage reduction was more than one-third (above 31.4%). Progressive increase in the percentage reduction predicted more abstinence (OR = 1.90, 95%CI 1.01-3.58). CONCLUSIONS Greater percentage reduction by at least one-third and progressive reduction predicted abstinence in those who reduced smoking. Such new evidence can guide the improvement of clinical service for tobacco dependency treatment and support further studies on smoking reduction and cessation.