A moderated mediation analysis of the association between smoking and suicide attempts among adolescents in 28 countries

Globally, evidence has shown that many adolescents are victims of substance use, mainly cigarette smoking, and it has been associated with suicidal ideation. However, the mechanisms underlying this association are poorly understood. This study examines whether truancy mediates and gender moderates the association of cigarette smoking with suicide attempts among adolescents in 28 countries. Data from the Global School-Based Student Health Survey were used. Hierarchical multiple logistic regression analyses were used to estimate the effect-modification of gender on cigarette smoking and suicide attempt. The mediating effect of truancy on the association between cigarette smoking and suicidal attempt was assessed using the generalized decomposition method. Cigarette smoking was associated with suicide attempts after adjusting for several confounding variables (aOR = 1.21; 95% CI = 1.09–1.33). The bootstrap results from the generalized decomposition analysis indicated that truancy partially mediated the association of cigarette smoking with a suicide attempt, contributing 21% of the total effect among in-school adolescents. Hierarchical regression analyses suggested that gender moderated the effect of cigarette smoking on suicidal attempts: female adolescents who smoked had 36% higher odds of suicidal attempts compared to male adolescents. The findings suggest possible pathways for designing and implementing interventions to address adolescents' cigarette smoking and truancy to prevent suicidal attempts.