Weaning From Tobacco with Nicotine or Varenicline in Severe and Mild Tobacco Dependence—Findings of a Meta-Analysis.

Abstract

Systematic reviews have documented the beneficial effects of bupropion, cytisine, nicotine, and varenicline as aids to permanent smoking cessation. We investigated the question whether the effect of treatment depends on the severity of tobacco dependence. We systematically searched for relevant publications in bibliographic databases and trial registries, made inquiries to manufacturers, and consulted additional sources of information (last search on 1 September 2022). The smokers included in the present study were classified as mildly or severely tobacco-dependent on the basis of their scores on the Fagerström Test for Nicotine Dependence, with variable cut-off values (FTND score 4, 5, or 6). In this meta-analysis, we determined the results with respect to the endpoint of sustained smoking cessation at 6 and 12 months in each of the two subgroups and investigated the heterogeneity between them. No subgroup analyses that could enable us to answer the question posed in this meta-analysis were available for either bupropion or cytisine. Subgroup analyses were available for varenicline in 12 studies, involving a total of 9723 smokers, and for nicotine in 23, involving 15 003 smokers. No statistically significant heterogeneity (p > 0.05) between mildly and severely tobacco-dependent smokers was found for the effect of either drug on the endpoint sustained smoking cessation (at 6 and 12 months), and this was so independently of the FTND cut-off value that was used. The benefit of varenicline and nicotine as aids to smoking cessation is independent of the severity of tobacco dependence.