Schools were selected to reflect socioeco - nomic diversity across the city"
Classes within selected schools randomised o one of three intervention programmes
No method of randomisation stated.
No controls within selected schools. Control group from previous study.
Clusters: Schools
Cluster constraint: Not stated
Baseline comparability: No significant dif- ferences in smoking rates at baseline be tween groups. Classes did not differ on gen- der and had representations in classes from all age groups in the school (intervention)