To determine the relation between extent of restrictions on smoking at home, at school, and in public places and smoking uptake and smoking prevalence among school students.
Cross sectional survey with merged records of extent of restrictions on smoking in public places.
17287 high school students.
Main outcome measures
Five point scale of smoking uptake; 30 day smoking prevalence.
More restrictive arrangements on smoking at home were associated with a greater likelihood of being in an earlier stage of smoking uptake (P<0.05) and a lower 30 day prevalence (odds ratio 0.79 (95% confidence interval 0.67 to 0.91), P<0.001). These findings applied even when parents were smokers. More pervasive restrictions on smoking in public places were associated with a higher probability of being in a earlier stage of smoking uptake (P<0.05) and lower 30 day prevalence (0.91 (0.83 to 0.99), P=0.03). School smoking bans were related to a greater likelihood of being in an earlier stage of smoking uptake (0.89 (0.85 to 0.99), P<0.05) and lower prevalence (0.86 (0.77 to 0.94), P<0.001) only when the ban was strongly enforced, as measured by instances when teenagers perceived that most or all students obeyed the rule.
These findings suggest that restrictions on smoking at home, more extensive bans on smoking in public places, and enforced bans on smoking at school may reduce teenage smoking.