Nicotine Replacement Therapy to Reduce Continued Tobacco Use

A Cochrane review [Abstract] 1 included 24 trials about interventions to help smokers cut down the amount smoked. Nicotine replacement therapy (NRT) significantly increased the odds of reducing cigarettes per day (CPD) by 50% or more for people using nicotine gum or inhaler or a choice of product compared to placebo (RR 1.75, 95% CI 1.44 to 2.13; 8 trials, n=3 081). Where average changes from baseline were compared for different measures, CO and cotinine consistently showed smaller reductions than CPD. Small numbers of smokers in either treatment or control group successfully sustained a reduction of 50% or more. Use of NRT increased the odds of quitting (RR 1.73, 95% CI 1.36 to 2.19).

A Cochrane review [Abstract] 2 assessed the effect of reduction-to-quit interventions on long-term smoking cessation. Reduction aided by pharmacotherapy resulted in higher quit rates compared to reduction alone (RR 1. 68, 95% CI 1.09 to 2.58; 11 studies, n=8636, I²=78%). However, a significant subgroup analysis suggested that this may only be true when fast-acting NRT or varenicline are used and not when nicotine patch, combination NRT or bupropion are used.

Comment: The quality of evidence is downgraded by study quality (inadequate or unclear allocation concealment) and by inconsistency (heterogeneity).

References

• Lindson-Hawley N, Hartmann-Boyce J, Fanshawe TR et al. Interventions to reduce harm from continued tobacco use. Cochrane Database Syst Rev 2016;(10):CD005231. [PubMed]
• Lindson N, Klemperer E, Hong B et al. Smoking reduction interventions for smoking cessation. Cochrane Database Syst Rev 2019;(9):CD013183. [PubMed]