Sociodemographic Factors Mediate Race and Ethnicity-associated Childhood Asthma Health Disparities: a Longitudinal Analysis.

Background: Race and ethnicity-based disparities in childhood asthma are well established. We characterized the longitudinal effects associated with being African-American/Black or Hispanic/Latino on a range of asthma outcomes, and the extent to which sociodemographic factors, caregiver health literacy, education level, and asthma knowledge mediate these associations.
Methods: Children ages 8-15 and their caregivers (n = 544) in the Chicago Initiative to Raise Asthma Health Equity (CHIRAH) cohort completed interviews every 3 months for 1.5 years. Health literacy was measured with the Rapid Estimate of Adult Literacy in Medicine (REALM). Other covariates include sex, age, education level, income, smoke exposure, asthma duration, employment status, and insurance status. We conducted a series of models to evaluate these factors as mediators of the relationship between race/ethnicity and (1) asthma knowledge, (2) asthma-related quality of life, (3) asthma severity, and (4) asthma control based on NAEPP/EPR-3 2007 guidelines.
Results: African-American race and Hispanic/Latino ethnicity were significantly associated with all outcomes when compared to Whites. Adjusting for sociodemographic factors resulted in the most significant mediation of racial/ethnic disparities in all outcomes. Health literacy was a partial mediator of race/ethnic disparities in asthma knowledge and asthma-related quality of life. Asthma knowledge remained significantly associated with race and ethnicity, and race remained associated with asthma-related quality of life.
Conclusions: African-American race and Hispanic/Latino ethnicity are significantly associated with worse asthma compared to Whites in longitudinal analyses. Sociodemographic factors are potent mediators of these disparities, and should be considered when designing interventions to reduce asthma disparities. Health literacy and education level are partial mediators.