Conclusion
SECONDARY, STILL
This study showed no overall intervention effects on daily cigarette consumption and smoking status. Still, results based on subgroup analyses indicated some context-specific effects. Hence, our results showed effects in social and health care VET schools and among girls. Moreover, findings suggested that smoking can be reduced if the intervention is fully implemented with both individual and structural components at the school level. We found inconclusive evidence on the investigated secondary outcomes that were determinants expected to impact smoking decisions, and future studies should further examine the mechanisms contributing to reduced smoking among some groups of youth and why other groups maintain their smoking habits.