Schools were selected to reflect socioeconomic diversity across the city"
Classes within selected schools randomised to 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 differences in smoking rates at baseline be tween groups. Classes did not differ on gender and had representations in classes from all age groups in the school (intervention)