Smokefree workplace and public place laws stimulate voluntary smokefree cars

Kai-Wen Cheng, Cassandra Okechuskwu, Robert McMillen, and I just published "Association between clean indoor air laws and voluntary smokefree rules in homes and cars" in Tobacco Control.
 
Here is the abstract (with a couple technical terms replaced with plain English):

Objectives This study examines the influence that smokefree workplaces, restaurants and bars have on the adoption of smokefree rules in homes and cars, and whether there is an association with adopting smokefree rules in homes and cars.

Methods [Statistical analysis was] used to jointly estimate the likelihood of living in a smokefree home and having a smokefree car as a function of law coverage and other variables. Household data were obtained from the nationally representative Social Climate Survey of Tobacco Control 2001, 2002 and 2004–2009; clean indoor air law data were from the American Nonsmokers’ Rights Foundation Tobacco Control Laws Database.

Results ‘Full coverage’ and ‘partial coverage’ smokefree legislation is associated with an increased likelihood of having voluntary home and car smokefree rules  compared with ‘no coverage’. The association between ‘full coverage’ and smokefree rule in homes and cars is 5% and 4%, respectively, and the association between ‘partial coverage’ and smokefree rules in homes and cars is 3% and 4%, respectively. There is a positive association between the adoption of smokefree rules in homes and cars.

Conclusions Clean indoor air laws provide the additional benefit of encouraging voluntary adoption of smokefree rules in homes and cars.

The paper is available at http://tobaccocontrol.bmj.com/content/early/2013/10/10/tobaccocontrol-20...