UCLA

Background

Asthma disproportionately affects individuals with lower income. High uninsured rates are a potential driver for this disparity. Previous studies have not examined the effect of the Affordable Care Act (ACA) on asthma-related outcomes for individuals with low income.

Research question

What is the impact of insurance status and the ACA on asthma outcomes for adults 18 to 64 years of age in households with low-income status?

Study design and methods

This study was a pooled cross-sectional observational study using National Health Interview Survey data from 2011 through 2013 and 2016 through 2018. Individuals 18 to 64 years of age with a history of asthma and low income were included. Survey-weighted regression modeling and mediation analysis was used to explore the relationship of insurance status and asthma control. Univariate and multivariate survey-weighted regression modeling then was used to evaluate the correlation of the ACA and asthma outcomes.

Results

We identified 4,043 individual observations. Having health insurance was correlated with improved asthma outcomes (OR, 1.25). This relationship was completely mediated by cost barriers to medications and physician visits. Although the ACA resulted in significant changes in insurance status (OR, 2.4), no statistically significant change was found in asthma outcomes. Furthermore, cost barriers to both medications and physician visits persisted in the insured population, 20.7% and 30.0%, respectively.

Interpretation

Insurance coverage is associated with improved asthma control for adults 18 to 64 years from households with low socioeconomic status. The ACA reduced the rates of uninsured, but did not have the same magnitude of effect on reducing cost barriers. The persistence of cost barriers may explain in part the lack of population-level improvement in asthma control.