Understanding the impact of school tobacco policies on adolescent smoking behaviour: A realist review

•School tobacco policies (STPs) may trigger four responses that decrease adolescent smoking.•STPs may also trigger responses that reduce, nullify or revert the positive responses.•Adequate implementation triggers the positive and prevents the negative responses.•Schools can use monitoring and adaptation cycles to steer STPs' impact.

BackgroundSecondary schools increasingly implement school tobacco policies (STPs) to decrease adolescents' smoking. Recent studies suggested that STPs' impact depends on their implementation. We examined adolescents' cognitive and behavioural responses to STPs that impact adolescents' smoking and how these responses depend on elements of STPs' implementation.MethodTo examine STPs and adolescent smoking, we performed a realist review, which is an explanatory approach that synthesizes existing evidence into a program theory that links elements of STPs' implementation to outcomes by specifying its underlying generative mechanisms. The search was performed in MEDLINE/PubMed, PsycINFO, and Embase between January 1991 and 2016. Thirty-seven English language articles were identified for inclusion, reporting quantitative and/or qualitative primary evidence on STPs at secondary schools, adolescent smoking behaviour, and mechanisms. From these articles, evidence was extracted about mechanisms that decrease smoking and associated countervailing-mechanisms that reduce, nullify, or revert this positive impact.ResultsThe program theory showed that STPs may trigger four mechanisms and seven associated countervailing-mechanisms. Adolescents' smoking decreases if STPs make them feel they can get sanctioned, feel less pressure to conform to smokers, internalise anti-smoking beliefs, and find it easier to stick to the decision not to smoke. This positive impact may reduce, nullify, or revert if the implementation of STPs cause adolescents to find alternative places to smoke, develop new social meanings of smoking, want to belong in smoker groups, internalise beliefs that smoking is not bad or that it asserts personal autonomy, or alienate from schools and schools' messages. The program theory, moreover, provided insights on how elements of STPs' implementation trigger mechanisms and avoid the countervailing-mechanisms.ConclusionSTPs' impact can be influenced by adequate implementation and embedding them in continuous monitoring and adaptation cycles, so that schools can proactively deal with the cognitive and behavioural responses that lead to suboptimal or adverse outcomes.