Abstract
BACKGROUND: This study examined the relationship between smoke-free home (SFH) rules and susceptibility to cigarette and e-cigarette (EC) use in never-smoking adolescents in Hong Kong, focusing on the mediating role of tobacco-related attitudes. METHODS: The sample included 5,902 secondary school students (grades 7-12; 51.9% male; mean age 14.6) from a territory-wide survey in Hong Kong. Generalised linear mixed models were used to estimate the association between SFH rules and tobacco susceptibility, and structural equation models (SEM) were used to explore the mediating effect of attitudes. All tests were two-tailed with a significance level of α = 0.05. RESULTS: Twenty-five point two percent of participants were living with smokers, of whom 27.3% had no SFH rules, 29.5% had rules with violations, and 43.1% had rules without violations. Students from smoking families had higher prevalence of smoking susceptibility and secondhand smoke exposure, with the highest levels observed among those without SFH rules. Having SFH rules without violations was negatively associated with susceptibility to both cigarette (adjusted Odds Ratio(aOR) = 0.51, 95%CI:0.31, 0.84; AME=-0.036, 95%CI: -0.066, -0.006) and EC use (aOR = 0.63, 95%CI:0.41-0.98; AME=-0.034, 95%CI: -0.068, -0.0001) after adjusting for covariates. SEM results showed that SFH rules with violations were associated with lower cigarette susceptibility both directly (β=-0.280) and indirectly through attitudes (β(cigarette)= -0.073, β(ec)=-0.097). SFH without violations were indirectly associated via less tolerant tobacco attitudes (β(cigarette)=-0.036, β(ec)=-0.050). CONCLUSIONS: SFH rules, especially strict rules without violations, were associated with lower susceptibility to cigarette or EC use, and this association was partly mediated through less tolerant attitudes toward tobacco use. Further research on policies and interventions on SFH rules and practice is warranted for effective tobacco prevention.