Search

This study aimed to examine the efficacy of school-based e-cigarette preventive interventions via a systematic review and meta-analysis. We searched Medline, Embase, PsycINFO, Scopus, CINAHL, Cochrane, and clinical trial registries for studies published between January 2000 and June 2023 using keywords for e-cigarettes, adolescents, and school. Of 1566 double-screened records, 11 met the criteria of targeting adolescents, evaluating an e-cigarette preventive intervention, being conducted in a secondary school, using a randomized controlled trial (RCT), cluster RCT, or quasi-experimental design, and comparing an intervention to a control. Pre-specified data pertaining to the study design, outcomes, and quality were extracted by one reviewer and confirmed by a second, and where necessary, a third reviewer. Meta-analyses found no evidence that school-based interventions prevented e-cigarette use at the longest follow-up, which ranged between 6 and 36 months post-intervention (OR = 0.43, 95% CI = 0.16, 1.12; p = 0.09). However, subgroup analyses identified significant effects at post-test and when studies with < 12-month follow-up were omitted. No effect was found for tobacco use at the longest follow-up (OR = 1.01, 95% CI = 0.65, 1.59, p = 0.95); however, reductions in past 30-day tobacco use (OR = 0.59, 95% CI = 0.39, 0.89, p = 0.01) which encompassed e-cigarettes in some studies were identified. Narrative synthesis supported these mixed results and found some school-based interventions prevented or reduced e-cigarette and/or tobacco use; however, some increased use. School-based interventions were also associated with improved knowledge (SMD = - 0.38, 95% CI = - 0.68, - 0.08, p = 0.01), intentions (SMD = - 0.15, 95% CI = - 0.22, - 0.07, p = 0.0001), and attitudes (SMD = - 0.14, 95% CI = - 0.22, - 0.06; p = 0.0007) in the short term. Overall, the quality of evidence was low-to-moderate. School-based interventions hold the potential for addressing e-cigarette use, however, can have null or iatrogenic effects. More high-quality research is needed to develop efficacious interventions, and schools must be supported to adopt evidence-based programs. This is the first systematic review and meta-analysis to examine the efficacy of school-based preventive interventions for e-cigarette use. It provides crucial new knowledge about the efficacy of such interventions in preventing e-cigarette use and improving other outcomes (e.g., tobacco use, knowledge, intentions, attitudes, and mental health) among adolescents and the key characteristics associated with efficacious interventions. Our findings have important practical implications, highlighting future research directions for the development and evaluation of e-cigarette preventive interventions, along with the need to provide support to schools to help them identify and adopt evidence-based programs.

Lifestyle risk behaviours--physical inactivity, poor diet, poor sleep, recreational screen time, and alcohol and tobacco use--collectively known as the "Big 6" emerge during adolescence and significantly contribute to chronic disease development into adulthood. To address this issue, the Health4Life program targeted the Big 6 risk behaviours simultaneously via a co-designed eHealth school-based multiple health behaviour change (MHBC) intervention. This study used multiple causal mediation analysis to investigate some potential mediators of Health4Life's effects on the Big 6 primary outcomes from a cluster randomised controlled trial of Health4Life among Australian school children. Mediators of knowledge, behavioural intentions, self-efficacy, and self-control were assessed. The results revealed a complex pattern of mediation effects across different outcomes. Whilst there was a direct effect of the intervention on reducing moderate-to-vigorous physical activity risk, the impact on sleep duration appeared to occur indirectly through the hypothesised mediators. Conversely, for alcohol and tobacco use, both direct and indirect effects were observed in opposite directions cancelling out the total effect (competitive partial mediation). The intervention's effects on alcohol and tobacco use highlighted complexities, suggesting the involvement of additional undetected mediators. However, little evidence supported mediation for screen time and sugar-sweetened beverage intake risk. These findings emphasise the need for tailored approaches when addressing different risk behaviours and designing effective interventions to target multiple health risk behaviours. The trial was pre-registered with the Australian and New Zealand Clinical Trials Registry: ACTRN12619000431123.