Objectives: We evaluated the impact of comprehensive statewide smoke-free indoor air laws on secondhand smoke (SHS) exposure, asthma prevalence, and asthma-related doctor visits.
Methods: We used the 2007-2011 Behavioral Risk Factor Surveillance System data sets. We employed a paired t test to determine whether comprehensive statewide smoke-free indoor air laws reduced SHS exposure. We performed weighted logistic and Poisson regressions to obtain likelihood of reporting asthma symptoms and incidence rate ratio (IRR) of doctor visits owing to severe asthma symptoms.
Results: After such laws were enacted, people in states with comprehensive smoke-free indoor air laws had a lower level of SHS exposure (P < .01), decreased odds of reporting current asthma symptoms (adjusted odds ratio [AOR] = 0.57; 95% confidence interval [CI] = 0.51, 0.63), and a decreased frequency of doctor's visits owing to severe asthma symptoms (IRR = 0.80; 95% CI = 0.69, 0.92) than did their counterparts in fully adjusted models.
Conclusions: Comprehensive statewide smoke-free indoor air laws appear to be effective in reducing SHS exposure and improving asthma outcomes. Regulations requiring smoke-free indoor environments and public areas are beneficial, and smoke-free indoor air laws should be enforced in all states.