Effectiveness of the State of Indiana's Smoke-Free Indoor Air Law on Adult Smoking Prevalence

Introduction: Tobacco smoking is a well-known risk factor of various chronic diseases for both smokers and non-smokers who are exposed to secondhand smoke. Thus, regulating tobacco use in public places has been an important public health effort to protect non-smokers from the harmful effects of exposure to secondhand smoke. This study evaluated the effect of the implementation of the State of Indiana’s statewide smoke-free air law implemented in 2012 that prohibited smoking in all restaurants and non-hospitality workplaces.

Methods: This study used a nonequivalent control group design with multi-year cross-sectional data from the 2011-2013 Behavioral Risk Factor Surveillance System. The State of Tennessee served as the control group as it did not implement such a statewide public smoking ban during the study period. The difference-in-difference method and multiple logistic regressions were used to evaluate its effect on the prevalence of cigarette smoking in Indiana adult residents.

Results: The prevalence of cigarette smoking in Indiana significantly dropped from 25.7% in 2011-2012 to 23.7% in 2013 (p<0.05) whereas no significant change was observed in Tennessee. Indiana residents were less likely to smoke cigarettes after the implementation of the public smoking ban in 2012 compared to Tennessee residents (OR=0.79, 95% CI: 0.67, 0.94).

Conclusions: Indiana’s Smoke-Free Indoor Air Law was effective in reducing adult cigarette smoking prevalence although it was not comprehensive enough to include bars in the smoking prohibited areas. This adds to the evidence that public smoking bans at any levels help reduce smoking prevalence in the affected area.