Background: We reviewed the evidence that School tobacco policies (STPs) might prevent smoking initiation among adolescents, as there may be some evidence that the school environment can influence young people to smoke. STP is intended to regulate whether and where pupils can smoke, adult smoking in school, and penalties for pupils caught smoking. We were also interested to know whether specific components of STPs might increase their impact. Components such as a smoking ban for students and/or teachers and their extent, levels of enforcement, monitoring strategies, sanctions for students or teachers found smoking, and the offer of tobacco cessation programmes.
Study characteristics: Our study search was conducted in May 2014. We identified one c-RCT from China that we judged to be at high risk of bias. We also focussed on 24 observational studies to generate a hypothesis for future research.
Key findings: In the only included c-RCT with 1807 participants, the intervention did not significantly affect students' smoking behavior. The majority of observational studies reported that schools with highly enforced policies, smoking ban extended to outdoor spaces, involving teachers and including sanctions for transgressions, with assistance to quit for smokers plus support by prevention programmes, did not show a significant difference in smoking prevalence, when compared to schools adopting weaker or no policies.
Quality of the evidence: We found no relevant high-quality experimental studies. A great limitation within observational studies is the heterogeneity of exposure definitions. There is large variability in policy formats, which can include several different characteristics, which in turn makes comparison difficult. Only a few studies are based on policy definition in written documents, while in the majority the information was obtained by interviewing school heads, teachers or administrators. With regard to analysis methods, some studies did not mention any adjustment for potential confounders and in the others there was a large variability in the factors considered for adjustment. Studies differed in statistical methods employed to examine the relationship between policy and smoking behaviour.
Conclusions: We cannot draw conclusions about the effectiveness of STP from currently available data. Large, possibly multi-centric studies, employing experimental or a quasi-experimental design to assess the effectiveness of STPs are needed. Characteristics that could be studied are: degree of formality, participants to which the policy applies, extension of the ban (indoor areas or external school premises), level of enforcement, sanctions for transgression; assistance with smoking cessation and combination with prevention and education activities.
The authors of the review did not receive any external funding or grants to support their research for this review, and have no potential conflicts of interest.
Despite a comprehensive literature search, and rigorous evaluation of studies, we found no evidence to support STPs. The absence of reliable evidence for the effectiveness of STPs is a concern in public health. We need well-designed randomised controlled trials or quasi-experimental studies to evaluate the effectiveness of school tobacco policies.
School tobacco policies (STPs) might prove to be a promising strategy to prevent smoking initiation among adolescents, as there is evidence that the school environment can influence young people to smoke. STPs are cheap, relatively easy to implement and have a wide reach, but it is not clear whether this approach is effective in preventing smoking uptake.
To assess the effectiveness of policies aiming to prevent smoking initiation among students by regulating smoking in schools.
We searched seven electronic bibliographic databases, including the Cochrane Tobacco Addiction Group specialized register, MEDLINE, EMBASE, PsycINFO and ERIC. We also searched the grey literature and ongoing trials resources. The most recent search was performed in May 2014.
We included cluster-randomised controlled trials (c-RCTs) in which primary and secondary schools were randomised to receive different levels of smoking policy or no intervention. Non-randomised controlled trials, interrupted time series and controlled before-after studies would also have been eligible. Cross-sectional studies were not formally included but we describe their findings and use them to generate hypotheses to inform future research.
We independently assessed studies for inclusion in the review, and present a narrative synthesis, as the studies are too limited in quality to undertake a formal meta-analysis.
We found only one study which was eligible for inclusion in the review. It was judged to be at high risk of bias. The study compared two 'middle schools' from two different regions in China. The experimental conditions included the introduction of a tobacco policy, environmental changes, and communication activities, while the control condition was no intervention. After a year's follow-up the study found no differences in smoking prevalence between intervention and control schools. We also described 24 observational studies, the results of which we considered for hypothesis generation. In these, policy exposure was mainly described using face-to-face interviews with school staff members, and the outcome evaluation was performed using self-administered questionnaires. Most studies reported no differences in students' smoking prevalence between schools with formal STPs when compared with schools without policies. In the majority of studies in schools with highly enforced policies, smoking bans extended to outdoor spaces, involving teachers and including sanctions for transgressions, with assistance to quit for smokers plus support by prevention programmes, there was no significant difference in smoking prevalence when compared to schools adopting weaker or no policies.