Small-Area Estimation of Smoke-Free Workplace Policies and Home Rules in US Counties

The workplace and home are sources of exposure to secondhand smoke, a serious health hazard for nonsmoking adults and children. Smoke-free workplace policies and home rules protect nonsmoking individuals from secondhand smoke and help individuals who smoke to quit smoking. However, estimated population coverages of smoke-free workplace policies and home rules are not typically available at small geographic levels such as counties. Model-based small-area estimation techniques are needed to produce such estimates.

Self-reported smoke-free workplace policies and home rules data came from the 2014-2015 Tobacco Use Supplement to the Current Population Survey. County-level design-based estimates of the two measures were computed and linked to county-level relevant covariates obtained from external sources. Hierarchical Bayesian models were then built and implemented through Markov Chain Monte Carlo methods.

Model-based estimates of smoke-free workplace policies and home rules were produced for 3134 (of 3143) US counties. In 2014-2015, nearly 80% of US adult workers were covered by smoke-free workplace policies, and more than 85% of US adults were covered by smoke-free home rules. We found large variations within and between states in the coverage of smoke-free workplace policies and home rules.

The small-area modeling approach efficiently reduced the variability that was attributable to small sample size in the direct estimates for counties with data and predicted estimates for counties without data by borrowing strength from covariates and other counties with similar profiles. The county-level modeled estimates can serve as a useful resource for tobacco control research and intervention.

Detailed county- and state-level estimates of smoke-free workplace policies and home rules can help identify coverage disparities and differential impact of smoke-free legislation and related social norms. Moreover, this estimation framework can be useful for modeling different tobacco control variables and applied elsewhere, for example, to other behavioral, policy, or health related topics.