Interaction effects of screen time and fast-food consumption on suicidal behaviours: Evidence from a nationwide survey among Chinese adolescents.

ABSTRACT

BACKGROUND: Although screen time and fast-food consumption have been linked to suicidal behaviours, it is unclear whether their combined effects are associated with suicidal behaviours among adolescents. METHODS: A sample of 16,853 Chinese adolescents answered a standard questionnaire on screen time, fast-food consumption, and suicidal behaviours. A binomial logistic regression model was used to analyse the association between the three. An interaction model was used to examine the interaction effects of screen time and fast-food consumption on suicidal behaviours in adolescents. RESULTS: There were positive correlations between screen time, fast-food consumption, and suicidal behaviours, even after adjusting for confounding factors. Interaction analyses indicated that increased screen time on weekdays and fast-food consumption were associated with suicidal ideation. The relative excess risk of interaction, attributable proportions, and synergy index of interaction were 0.41, 0.15, and 1.32, respectively. Increased screen time on weekends and fast-food consumption were associated with suicidal ideation. The relative excess risk of interaction, attributable proportions, and synergy index of interaction were 0.37, 0.14, and 1.27, respectively. Similar additive interaction effects were exhibited in increased screen time and fast-food consumption on suicidal planning. Positive additive interaction effects were observed in increased screen time on weekdays and fast-food consumption on suicide attempts. LIMITATIONS: A cross-sectional study design was used; therefore, causal associations remain unclear. CONCLUSIONS: Screen time and fast-food consumption are cross-sectionally associated with suicidal behaviours among Chinese adolescents. Strategies should be considered to reduce screen time and fast-food consumption among adolescents.