Breakthrough Quit-Smoking Methods Unveiled: What Works and What's Missing, According to New Cochrane Reviews.
Study: Effects of interventions to combat tobacco addiction: Cochrane update of 2021 to 2023 reviews. Image Credit: Josep Suria/Shutterstock.com
In a recent study published in the Addiction, a group of researchers summarized Cochrane Tobacco Addiction Group (CTAG) systematic reviews published from 2021 to 2023, highlighting key findings on effective smoking cessation interventions and identifying areas for future research.
Background
Tobacco smoking is a leading cause of preventable death, responsible for over 8 million deaths annually, and a major contributor to health inequalities. Quitting smoking significantly improves health and reduces the risk of disease and death.
Evidence-based support for cessation and prevention is critical for healthcare providers and policymakers. Cochrane, a not-for-profit organization, produces systematic reviews to support informed healthcare decisions.
The CTAG focused on smoking cessation interventions until March 2023. Further research is needed to refine existing interventions, explore emerging therapies, and address gaps in understanding to enhance the effectiveness of tobacco addiction treatment and prevention strategies.
About the study
The present article provides detailed information on abstinence and harms. These comparisons include effect estimates, number of contributing studies, sample size, the certainty of the evidence, and statistical heterogeneity.
The data presented reflect the original published reviews, with certainty of evidence assessed using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) criteria, which consider study limitations, imprecision, indirectness, consistency of effect, and publication bias.
Certainty levels range from high, where the true effect is believed to be close to the estimate, to very low, indicating minimal confidence in the estimate.
Due to their inherent heterogeneity, CTAG generally used random-effects models for behavioral interventions, while pharmacotherapies and e-cigarette (EC) interventions were analyzed using fixed-effect models.
Cessation outcomes were analyzed on an intention-to-treat basis, counting participants lost to follow-up as continuing to smoke, following the Russell Standard. Adverse events (AEs) were analyzed on a complete-case basis where data allowed or otherwise on an intention-to-treat basis.
While there is some overlap in studies across reviews, the non-overlapping topics ensure that any shared studies contribute data to different intervention comparisons.
Study results
Between 2021 and 2023, the CTAG published five new reviews one overview, and updated eight previous reviews. This included a living systematic review updated three times. Another related review by the Cochrane Public Health Group, which investigated interventions to prevent or cease EC use in young people, found no studies.
CTAG also published protocols for two upcoming reviews, focusing on the impact of ECs on cigarette smoking in young people and interventions for smokeless tobacco cessation, both expected in 2024.
The updated reviews incorporated new evidence, particularly in the area of pharmacotherapies. For instance, the 2023 update on nicotine receptor partial agonists found that varenicline and cytisine were more effective for smoking cessation than placebo, with varenicline showing higher efficacy than bupropion or nicotine replacement therapy (NRT).
Cytisine may have fewer serious AEs (SAEs) compared to varenicline. Similarly, an updated review of antidepressants for smoking cessation reaffirmed that bupropion helps more people quit compared to placebo, although there was some evidence suggesting potential AEs.
CTAG's review of NRT added new studies but did not change its overall conclusions. Combination NRT, particularly fast-acting forms with patches, was more effective than single-form NRT.
Evidence also supported the use of pre-loading NRT before the quit date. There was mixed evidence regarding different doses and forms of NRT, with limited data on safety comparisons.
A new review using component network meta-analysis (cNMA) provided insight into the comparative effectiveness of smoking cessation interventions. Nicotine ECs, varenicline, and cytisine emerged as the most effective treatments.
The review also found moderate evidence suggesting bupropion may slightly increase SAEs. This technique allowed comparisons between treatments that had not been directly studied, offering new insights into intervention effectiveness.
Behavioral interventions were also assessed. An overview of reviews found that behavioral support, such as counseling and financial incentives, improved quit rates.
The economic evaluation suggested all effective behavioral interventions were cost-effective, though no particular method was found to be superior. Lastly, updated reviews on waterpipe cessation, mindfulness, and preventing weight gain post-smoking cessation offered mixed or low-certainty evidence.
Conclusions
To summarize, from 2021 to 2023, Cochrane Tobacco Addiction updated key reviews using newer methods, including component network meta-analyses, a living systematic review, and an overview of reviews.
These approaches provided clear evidence of the effectiveness of smoking cessation interventions, but important gaps remain.
More trials are needed to compare dosages, durations, and combinations of pharmacotherapies, as well as safety data. Behavioral interventions, EC, and heated tobacco products also require further study.
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