Inequities in coverage of smokefree space policies within the United States.

Background: Previous studies have found extensive geographic and demographic differences in tobacco use. These differences have been found to be reduced by effective public policies, including banning smoking in public spaces. Smokefree indoor and outdoor spaces reduce secondhand smoke exposure and denormalize smoking.
Methods: We evaluated regional and demographic differences in the proportion of the population covered by smokefree policies enacted in the United States prior to 2014, for both adults and children.
Results: Significant differences in coverage were found by ethnicity, region, income, and education (p < 0.001). Smokefree policy coverage was lower for jurisdictions with higher proportions of poor households, households with no high school diploma and the Southeast region. Increased ethnic heterogeneity was found to be a significant predictor of coverage in indoor "public spaces generally", meaning that diversity is protective, with differential effect by region (p = 0.004) - which may relate to urbanicity. Children had a low level of protection in playgrounds and schools (~10% covered nationwide) - these spaces were found to be covered at lower rates than indoor spaces.
Conclusions: Disparities in smokefree space policies have potential to exacerbate existing health inequities. A national increase in smokefree policies to protect children in playgrounds and schools is a crucial intervention to reduce such inequities.