Tobacco smoking is a leading cause of preventable death globally. The World Health Organization (WHO) advocates for effective smoking cessation programs. While various interventions exist (physician advice, pharmacotherapy, internet-based programs), behavioral counseling, both individual and group-based, is a cornerstone of successful cessation. Group-based interventions offer advantages through social support, learning, and shared experiences. Previous reviews have shown their effectiveness compared to usual care or self-help, but there's significant variation in program formats. This review aimed to identify the specific components within these programs that contribute to their success, using the Behavior Change Technique (BCT) Taxonomy to systematically analyze the active ingredients of effective interventions.

A 2017 Cochrane review demonstrated improved smoking cessation rates for group-based interventions compared to usual care, self-help, and brief individual support. However, the lack of a standardized framework to analyze the components of these interventions hindered a deeper understanding of their effectiveness. The Behavior Change Technique (BCT) Taxonomy, a hierarchical list of 93 techniques, offers a method to systematically analyze and compare interventions, going beyond simply assessing whether they work to understanding how and why they work. Previous research successfully applied this taxonomy to internet-based smoking cessation programs, but its application to group-based interventions was lacking.

This systematic review and meta-analysis followed PRISMA guidelines and was registered on PROSPERO. Databases (MEDLINE, EMBASE, CINAHL, PsycINFO, The Cochrane Library, and Web of Science) were searched from January 2000 to March 2022 for English-language randomized controlled trials (RCTs) evaluating group-based smoking cessation programs. Data extraction included participant characteristics, intervention details, and BCTs identified using the BCT Taxonomy v1. Two reviewers independently extracted data, with inter-rater reliability assessed using Cohen's kappa. Risk of bias was assessed using the Joanna Briggs Institute (JBI) Critical Appraisal tool. Meta-analyses were conducted to assess 6-month smoking cessation rates and the association between specific BCTs and effectiveness. Random-effects models were used, and heterogeneity was assessed using I². Publication bias was evaluated using funnel plots and Egger's test.

The review included 19 RCTs. A total of 28 BCTs were identified, with an average of 5.42 ± 2.0 BCTs per study. The most frequent BCTs were "information about health consequences" and "problem-solving." The pooled 6-month smoking cessation rate was significantly higher in the group-based intervention group (OR = 1.75, 95% CI = 1.12 to 2.72, p < .001). Subgroup analysis using continuous abstinence showed a three-fold higher odds of cessation in the group intervention arm. Four BCTs were significantly associated with increased 6-month cessation: "problem-solving," "information about health consequences," "information about social and environmental consequences," and "reward (outcome)." The inclusion of "Information about social and environmental consequences" showed the strongest effect (OR = 8.55, 95% CI = 3.50 to 20.88, p < .001). Most effective interventions were implemented in community settings, often using five sessions delivered once or twice weekly, and were led by various healthcare professionals.

This review confirms the effectiveness of group-based smoking cessation interventions, showing a doubling of cessation rates at 6 months compared to control groups. The identification of specific BCTs associated with increased effectiveness provides valuable insights for program development and implementation. The finding that interventions incorporating information about social and environmental consequences were particularly effective highlights the importance of addressing the broader context of smoking behavior. While the average number of BCTs used was lower than in some other intervention types, increasing the number of BCTs, particularly those identified as effective, could further enhance program efficacy. The absence of pharmacological support in many interventions is noteworthy, considering the established benefits of combining behavioral and pharmacological approaches. The study's findings align with previous research on the effectiveness of specific BCTs but offers a more granular understanding by focusing specifically on group-based interventions and using the BCT taxonomy.

Group-based smoking cessation programs significantly improve quit rates. Incorporating specific BCTs, particularly information about health and social/environmental consequences, and problem-solving techniques, enhances effectiveness. Future research should focus on optimizing the combination of BCTs, exploring the differential effects across diverse populations (including Indigenous populations), and rigorously evaluating real-world program effectiveness. Further research is also needed to understand the relative cost-effectiveness of group-based versus intensive individual counseling.

The review relied on published data, potentially missing information not explicitly reported in publications. The relatively small number of studies and heterogeneity in interventions and populations limit the generalizability of findings. Combining interventions with different comparator arms in meta-analysis could have introduced confounding effects. Future research should focus on more comprehensive reporting of intervention components and conducting studies with larger sample sizes and more homogeneous populations.