A Systematic Review and Meta-Analysis of Interventions to Induce Attempts to Quit Tobacco Among Adults Not Ready to Quit

The prevalence of past-year smoking cessation remains below 10% in the U.S. Most who smoke are not ready to quit in the near future. Cessation requires both (a) initiating a quit attempt (QA) and (b) maintaining abstinence. Most research has focused on abstinence among people already motivated to quit. We systematically reviewed interventions to promote QAs among people not motivated to quit tobacco. We searched PubMed, CENTRAL, PsycINFO, Embase, and our personal libraries for randomized trials of tobacco interventions that reported QAs as an outcome among adults not ready to quit. We screened studies and extracted data in duplicate. We pooled findings of the 25 included studies using Mantel-Haenszel random effects meta-analyses when >= 2 studies tested the same intervention. Most (24) trials addressed cigarettes and one addressed smokeless tobacco. Substantial heterogeneity among trials resulted in a series of small meta-analyses. Findings indicate varenicline may increase QAs more than no varenicline, n = 320; RR = 1.4, 95% CI [1.1, 1.7]; I-2 = 0%, and nicotine replacement therapy (NRT) may increase QAs more than no NRT, n = 2,568; RR = 1.1, 95% CI [1.02, 1.3]; I-2 = 0%. Pooled effects for motivational counseling, reduction counseling, and very low nicotine content cigarettes showed no clear evidence of benefit or harm. The evidence was judged to be of medium to very low certainty due to imprecision, inconsistency, and risk of bias, suggesting that further research is likely to change interpretation of our results. Findings demonstrate the need for more high-quality research on interventions to induce QAs among adults not ready to quit tobacco. Public Health Significance Most people who use tobacco do not plan to quit in the near future and thus interventions to induce quit attempts are needed. This systematic review demonstrates that people who are unmotivated to quit smoking can benefit from treatment and found varenicline and nicotine replacement therapy are particularly promising interventions. However, evidence was insufficient to conclusively support or refute the effectiveness of any single modality and thus further research is needed.