Retail tobacco outlet density and and youth cigarette smoking: a propensity-modeling approach.

OBJECTIVES: We examined whether retail tobacco outlet density was related to youth cigarette smoking after control for a diverse range of neighborhood characteristics. METHODS: Data were gathered from 2116 respondents (aged 11 to 23 years) residing in 178 census tracts in Chicago, Ill. Propensity score stratification methods for continuous exposures were used to adjust for potentially confounding neighborhood characteristics, thus strengthening causal inferences. RESULTS: Retail tobacco outlets were disproportionately located in neighborhoods characterized by social and economic disadvantage. In a model that excluded neighborhood confounders, a marginally significant effect was found. Youths in areas at the highest 75th percentile in retail tobacco outlet density were 13% more likely (odds ratio [OR]=1.13; 95% confidence interval [CI]=0.99, 1.28) to have smoked in the past month compared with those living at the lowest 25th percentile. However, the relation became stronger and significant (OR=0.21; 95% CI=1.04, 1.41) after introduction of tract-level confounders and was statistically significant in the propensity score-adjusted model (OR = 1.20; 95% CI = 1.001, 1.44). Results did not differ significantly between minors and those legally permitted to smoke. CONCLUSIONS: Reductions in retail tobacco outlet density may reduce rates of youth smoking. [ABSTRACT FROM AUTHOR]