BACKGROUND: Co-use of tobacco and alcohol is common, with each substance triggering cravings that increase relapse risks when quitting either. Despite its prevalence, evidence on the effectiveness of interventions addressing both behaviours simultaneously remains unclear. We conducted a systematic review to evaluate the effectiveness of behavioural and/or pharmacological interventions targeting tobacco and alcohol co-use. This study was registered with PROSPERO (CRD42024553460) and followed PRISMA guidelines.
METHODS: We systematically searched PubMed, Embase, CINAHL, Web of Science, PsycINFO, Cochrane Central Register of Controlled Trials databases and reference lists from inception to August 2024. Randomized controlled trials (RCTs) examining behavioural and/or pharmacological interventions specifically designed to target both tobacco and alcohol co-use in concurrent users were included. Primary outcomes were both tobacco abstinence (e.g. self-reported/biochemically validated) and alcohol reduction (e.g. self-reported drinking quantity, frequency, or intensity). Two reviewers independently screened studies, extracted data, and assessed risk of bias using Cochrane Risk of Bias 2 tool.
RESULTS: A total of 18912 articles were identified, of which 79 underwent full-text screening, and 25 RCTs (N=7629 participants) were included. Daily smokers (20 studies) and heavy drinkers (15 studies) were the most commonly studied populations. Seven studies tested behavioural interventions only (e.g., counselling, self-help materials), 3 focused on pharmacological interventions only (e.g., varenicline, nicotine replacement therapy), and 15 tested the combined behavioural and pharmacological approaches, with follow-ups ranging from 2 to 52 weeks. Seven studies showed statistically significant effects on dual outcomes. Among these, the most effective intervention components were personalized feedback, self-monitoring, and achievable goal settings for quitting smoking and alcohol control.
CONCLUSIONS: Evidence on interventions targeting tobacco and alcohol co-use is mixed, with combined behavioural-pharmacological approaches showing promising effects. Future research should focus on populations with varying dependence levels, refine strategies, and examine mechanisms to improve dual outcomes. Rigorous, long-term trials are needed to establish clinical recommendations.