Social Determinants of Health and Racial Disparities in Lung Function: Findings from NHANES 2007-2012

We hypothesized that the disproportionate impact of social determinants of health (SDoH) captured in survey data could help explain a larger proportion of racial gaps in lung function than previously reported. We defined a series of nested, increasingly healthy reference populations using data from NHANES 2007-2012. Starting with non-smokers without respiratory symptoms or diagnoses, we sequentially excluded those with confirmed occupational exposure to dust/fumes, physical inactivity, maternal or second-hand tobacco use, obesity, no home ownership, no insurance, lower education, and self-reported unhealthy diet. Across successive populations, we compared average age-, sex-, and height-adjusted differences in FEV1 and FVC between racial and ethnic minority groups and Non-Hispanic White participants for adults (≥20) and children (6-19). In successively healthier reference populations, the proportion of represented participants declined for Non-Hispanic Black, Mexican American, and Other Hispanic, increased for non-Hispanic White, and remained stable for Non-Hispanic Asian participants. At baseline, adjusted FEV1 and FVC were similar for Mexican Americans and non-Hispanic White Americans, but lower for other racial and ethnic minority groups. After excluding individuals with unfavorable SDoH, racial disparities in FEV1 and FVC decreased for Non-Hispanic Black children (24.8% and 26.2%) and adults (26.3% and 19.4%), Other Hispanic children (15.2% and 19.3%) and adults (85.9% and 12.4%), and Non-Hispanic Asian children (6.6% and 12.5%), but increased for Non-Hispanic Asian adults (14.1% and 11.1%). Unfavorable SDoH disproportionately affected non-Hispanic Black, Mexican American, and Other Hispanic populations, and explained a higher proportion of racial disparities in lung function than previously reported.