The association between smoke-free school policies and adolescents’ anti-smoking beliefs: moderation by family smoking norms

Background: Smoke-free school policies (SFSPs) may influence adolescents’ smoking through the development of anti-smoking beliefs. We assessed which types of anti-smoking beliefs (health, social and societal) are associated with SFSPs and whether these associations were different for adolescents in smoking permissive versus prohibitive families. Methods: Survey data was collected in 2016–2017 from 10,980 adolescents between 14–16 years old and 315 staff in 55 schools from seven European cities. We separately measured adolescent-perceived SFSP and staff-reported SFSP at the school-level. Associations between SFSP and anti-smoking health, social and societal beliefs were studied using multi-level logistic regression, adjusting for demographics and school-level smoking prevalence. We tested for interactions between family norms and SFSP, and estimated associations for adolescents in permissive and prohibitive families, respectively. Results: Adolescent-perceived SFSP was not significantly associated with anti-smoking health (OR:1.08, 95%CI:0.94–1.25), social (OR:0.89, 95%CI:0.75–1.04) and societal beliefs (OR:1.15, 95%CI:0.99–1.33). Staff-reported SFSP were associated with anti-smoking health beliefs (OR:1.12, 95%CI:1.01–1.24), but not with social (OR:0.94, 95%CI:0.83–1.07) or societal beliefs (OR:1.02, 95%CI:0.90–1.14). Most results were comparable between adolescents in smoking prohibitive and permissive families. However, in smoking prohibitive families, adolescent-perceived SFSP were associated with societal beliefs (OR:1.24, 95%CI:1.06–1.46), but not in permissive families (OR:1.06, 95%CI:0.90–1.25). Also, in smoking permissive families, staff-reported SFSP were associated with more pro-smoking social beliefs (OR:0.83, 95%CI:0.72-0.96), but not in prohibitive families (OR:1.05, 95%CI:0.92-1.16). Conclusions: We found evidence that SFSP are associated with some anti-smoking beliefs, but more so among adolescents from smoking prohibitive families than from permissive families.