How effective are primary prevention interventions to prevent tobacco use for children and youth? An overview of systematic reviews
Systematic review
|Published
We conducted an overview of reviews to examine the effects of primary tobacco prevention interventions – delivered in small social environments – for children and youth.
Key message
Tobacco is addictive and it’s adverse effects on many health outcomes, such as respiratory tract problems and cancer, are well known. Yet, there is still a considerable, though decreasing, percentage of young people in Norway who use cigarettes.
Primary prevention programs delivered in schools and primary healthcare settings (i.e. small social environments) are some of the most cost effective ways of reaching children and youth.
We conducted an overview of reviews to examine the effects of primary tobacco prevention interventions – delivered in small social environments – for children and youth. The findings show that:
- Primary tobacco prevention interventions delivered in small social environments appear to be effective in preventing children and youth from starting to smoke.
- Some of the most effective programs to prevent smoking appear to be school curricula aiming to help youth refuse offers to smoke by improving their general social competencies (‘social competence curricula’), and social competence curricula combined with curricula providing skills to overcome social influences (‘social influence curricula’).
- Prevention programs in primary health settings appear to be effective with a risk reduction for smoking of 18-19%.
- Program characteristics that appear to increase effectiveness are those that last at least 12 months, are led by adults, have a focus on tobacco only, and use booster sessions.
- Interventions that do not seem to be effective in preventing children and youth from starting to smoke include school based interventions that use incentives, universal school-based resilience interventions, school based interventions for girls only, and those aimed solely at giving information/gaining knowledge.
Summary
Background
Health promotion and prevention interventions or programs originated in the movement towards addressing social determinants of health. One of the aims of these programs is to prevent an individual from starting a behaviour or activity, such as smoking, that could be damaging to their health now or in the future. Primary prevention interventions aim to intervene to prevent someone from starting an activity or intervene before negative health effects occur. Interventions can be targeted, designed with a specific group of people in mind, or universal, attempting to reach the largest number of people. These programs can be delivered to individuals, groups or society as a whole using a variety of methods including regulatory frameworks such as laws, mass media campaigns, face-to-face education, group involvement, teaching in schools or health services or online tools.
Tobacco has long been a focus of primary prevention programs. Its adverse effects on many health outcomes such as cancer are well known. Tobacco is also very addictive. Since good health and well-being in childhood are resources for future health, it is important to focus health promotion and prevention interventions on children and adolescents.
In Norway, there is still a significant, although decreasing number, of young people who smoke. Primary prevention interventions targeted at this age group are one way of influencing children and youth to say no to tobacco products. The most efficient way to reach a large number of children and youth at once is to implement programs in schools or in relation to contact with primary healthcare services, i.e. small social environments. In order to steer prevention efforts among children and youth towards areas and measures that have documented effect, it is important to get an overview of the effects of various preventive measures.
Objective
The objective of this overview of systematic reviews is to summarize and present existing systematic reviews on the effects of primary prevention interventions, delivered in small social environments, for tobacco for children and youth.
Method
We conducted an overview of systematic reviews. It is an update of an overview we published in 2012. Inclusion criteria were therefore systematic reviews published in 2012 or later, that assessed the effects of primary prevention interventions for tobacco, and were delivered in small social environments such as schools and primary healthcare services. The reviews could include studies with populations of children or youth aged 19 or younger. We searched ten electronic literature databases in April 2018. Two researchers independently screened titles and abstracts, and made final decisions on inclusion based on full text assessments. We assessed the methodological quality of eligible systematic reviews. We extracted data from high quality reviews, used the review authors’ findings, and, if available, assessment of confidence in the estimates of effect for each outcome using the GRADE methodology. If the authors did not do a GRADE assessment, we used available data to do one. Using GRADE, we express our confidence that the estimated effect is close to the anticipated effect of the intervention (the “true” effect) as high, moderate, low or very low for each outcome.
Results
Two researchers independently screened 5761 titles and abstracts, and made final decisions on inclusion based on 179 full text assessments. We assessed the methodological quality of 14 systematic reviews that assessed the effect of primary prevention interventions to prevent tobacco use among children and youth aged 19 and younger (here, to prevent means the same as to stop or hinder). We considered that seven systematic reviews (with 195 primary studies) had high methodological quality. Five of the included systematic reviews examined interventions delivered in school settings. Two examined interventions that were set in, or were relevant for, primary healthcare settings. The majority of the primary studies included in these reviews took place in North America, Europe and Australia. The majority of the approximately 500 000 participants were aged 12-19.
Five systematic reviews focused on primary prevention interventions delivered in schools. Interventions based on incentives, such as the smoke free class contest, and universal school-based resilience interventions did not appear to be effective in preventing children and youth from starting to smoke. There was also no evidence that gender-neutral school-based smoking prevention programs have a significant effect on preventing teenage girls from smoking. In contrast, we found that general school-based curricula were effective at long-term follow up (the effect was measured more than one year after the intervention started). At one year or less, only combined social competence/ social influence curricula were effective. At longest follow up, social competence curricula as well as combined social competence/ social influence curricula were effective. In sub-group analyses, the authors found that at longest follow up adult led interventions, with a tobacco only focus, and booster sessions were effective.
The two systematic reviews examining the effects of interventions given in, or relevant for, primary healthcare settings found that the interventions were probably effective, with a mean risk reduction in smoking of 18% and 19%. The numbers needed to treat were approximately 50. However, the interventions included in these two systematic reviews were highly varied. The authors concluded that the most effective interventions appeared to be tailored to prevention, focused only on tobacco, targeted individuals, were at least 12 months long and included education/information components.
Discussion
Together with the previous overview of systematic reviews, published in 2012, this overview offers a description of the effects of primary prevention interventions for tobacco over a very long period of time.
The contexts in this overview are highly varied, with studies taking place in a wide variety of geographic settings. However, the majority of the included primary studies were conducted in Europe, North America and Australia. The study populations, children and youth, in these countries are similar in age. On the other hand, smoking has different cultural, legal and social associations across these contexts. These may differ from how smoking is perceived by children and youth in Norway.
Based on the findings of this overview of systematic reviews, existing primary prevention programs could be examined to see if they are using the most effective theory and program components. Our findings suggest that a social competence curriculum combined with a social influence curriculum, focused on tobacco, delivered by an adult with booster sessions appeared to be the most effective type of intervention. However, none of the primary prevention interventions focused directly on snuff (chewing tobacco) or vaping so their effects on preventing use are not known. There was also a limited number of interventions delivered through digital platforms, something that is becoming more common as populations have increased access to internet and smart phones.
More research is needed on which intervention content, timing, delivery mechanism and intensity are most effective. There is also a need for better reporting of these elements in primary studies. With the growing number of adolescents in Norway who begin to use snuff future research should investigate whether existing interventions are effective in preventing the use of snuff or if new interventions need to be developed.
Conclusion
Primary tobacco prevention interventions delivered in small social environments appear to be effective in preventing children and youth from starting to smoke. The intervention that appears to be the most effective is school-based curriculum combining a social influence and social competence component or using a social competence component, focusing only on tobacco, led by an adult and using booster sessions.
