Do smoke-free policies in work and public places increase smoking in private venues?

Objective: To evaluate the correlation between the implementation of tobacco control policies, particularly smoke-free bans at work and in public places, and smoking prevalence in private venues in the 27 countries of the European Union.
Design: Ecological study with the country as the unit of analysis.
Data Sources: Data analysis of tobacco control activities in European countries in 2007 as compiled in the Tobacco Control Scale (TCS) and information on the level of smoking permissiveness in houses and cars from the Special Eurobarometer on Tobacco conducted in 2009.
Analysis: Spearman rank-correlation coefficients (rsp) and their 95% confidence intervals (CIs) were calculated.
Results: The correlation between the TCS score and the prevalence of smoking in private venues (houses and cars) where smoking inside was always allowed was close to zero. A similar lack of association was observed between the TCS score of specific bans at work and in public places and smoking rules inside houses and cars. There was a non-significant direct correlation between the TCS score and the prevalence of smoke-free houses (rsp=0.21, 95% CI -0.19 to 0.55) and a non-significant inverse correlation with smoking allowed in certain rooms inside the house (rsp=-0.34; 95% CI -0.64 to 0.05).
Conclusions: Smoke-free legislation in workplaces and public places is not correlated with increased smoking prevalence in private venues (houses and cars) at an ecological level.