Lower Socioeconomic Status May Help Explain Racial Disparities in Asthma and Atopic Dermatitis Prevalence: A Mediation Analysis

This study measured the proportion of racial disparities in childhood atopic dermatitis (AD) and asthma that are mediated by socioeconomic status (SES).The study population consisted of children (0–18 years; n = 59 658) who were identified as Black (n = 14,429) or non-Hispanic white (n = 45 229) by their caregiver(s) on the 2011–2018 National Health Interview Survey, an annual, nationally representative survey of US households. Together, the sample population represented a population size of 50.1 million children.Diagnoses for AD, asthma, and respiratory allergy as a proxy for allergic rhinitis were ascertained through caregiver-reported answers to questions in the National Health Interview Survey. Further information was obtained about persons living in the household and several SES variables. Pearson χ2 tests were used to analyze the differences in atopic disease prevalence by race and associations with potential mediators. Mediation analysis was conducted to simultaneously evaluate SES variables using complex statistical measures within a causal inference framework.Estimated AD prevalence was 11.8% (95% confidence interval [CI]: 11.4%–12.2%) in white children and 17.4% (95% CI: 16.6%–18.3%) in Black children. Estimated asthma prevalence was 7.4% (95% CI: 7.0%–7.7%) in white children and 14.3% (95% CI: 13.5%–15.0%) in Black children. Estimated respiratory allergy prevalence did not significantly vary by race (11.4% for white children and 10.9% for Black children). The degree to which SES mediators explained racial disparities varied by atopic disease; for AD, they included paternal education reported, receipt of food stamps, and food insecurity, and for asthma, they included home rental and assistance status, paternal education reported, income-poverty ratio, and receipt of food stamps. The percentage of disparity between white versus Black children and disease prevalence as explained by multivariable measurement of SES was 25% (95% CI: 15%–36%) for AD and 47% (95% CI: 40%–54%) for asthma.US Black children had a significantly higher prevalence of AD and asthma than non-Hispanic US white children in 2011 to 2018. In a multivariable model, 25% of AD-related and 47% of asthma-related racial disparities were explained by SES. As such, efforts to improve SES may help reduce racial disparities in the prevalence of these diseases.This is one of the first studies to link SES to disease prevalence and did so through utilization of a nationally representative data set and robust statistical methods. Potentially confounding factors, such as pollution information and family history of atopy, were not assessed, and certain measures could not be measured if a parent was not living in the home. However, the degree to which mediators of SES contributed to racial disparities varied by disease type and, remarkably, explained nearly half of the racial disparities for asthma. It is paramount that clinicians be attuned to socioeconomic factors that can impact patient care. Future studies should explore additional SES factors (eg, maternal hardship) and discretely consider disparities in Hispanic children, as well as in other allergic diseases (eg, food allergy). This study lends support to efforts aiming to reduce socioeconomic disparities in the prevalence of AD and asthma, which may include helping families navigate difficulties with housing and providing food assistance.