Background:
While the smoke-free workplaces legislation introduced in 2004 in Ireland has reduced adult smoking prevalence, its impact on youth prevalence is less clear. A particularly large reduction was observed in youth smoking prevalence between 2003 and 2007. This study sets out to assess if the smoking ban was effective in reducing youth smoking in Ireland and to see if it could explain the large fall in prevalence between 2003 and 2007.

Methods:
Data is from the European School Survey Project on Alcohol and Other Drugs (ESPAD) Ireland, which took place every four years from 1995 to 2015. A logistic regression model on grouped data was used. Dependent variable is whether a student was a smoker in last-30 day. Independent variables are time, gender and policy indicators, including workplace ban indicator and Point-of-Sale (POS) ban indicator.

Results:
Smoking prevalence among youths in Ireland has dropped from 41% in 1995 to 13% in 2015, an average annual reduction of 1.4% (95% confidence interval 1.3%-1.5%). The workplace ban had strongly significant impacts on reducing youth smoking, while the contribution of POS ban was negligible. In particular, a significantly improved fit was obtained by the model which included term for workplace ban with a 4.3% (1.2%-7.5%) reduction in prevalence, in addition to an average annual reduction of 1.1% (0.8%-1.3%).


[Prevalence and fitted regression lines]



Conclusions:
The workplace ban introduced in 2004 has significantly helped to explain the out-of-trend reduction in youth smoking prevalence, although the legislation was not particularly targeting youths. While removal of point of sale tobacco promotion was to reduce awareness of smoking among young people, its impact on prevalence was insignificant. The significance of time variable may capture the impact of other tobacco control policies implemented, particularly tax increase every year. There were no school-specific policies introduced during this period.