Medicaid expansion, health insurance coverage, and cost barriers to care among low-income adults with asthma: the Adult Asthma Call-Back Survey.

OBJECTIVE: To examine Medicaid expansion (ME) effects on health insurance coverage (HIC) and cost barriers to medical care among people with asthma. METHOD: We analyzed 2012-2013 and 2015-2016 data from low-income adults with current asthma aged 18-64 years in the Behavioral Risk Factor Surveillance System Asthma Call-Back Survey (state-level telephone survey). We calculated weighted percentages and 95% confidence intervals from ME and non-ME jurisdictions (according to 2014 ME status). Outcomes were HIC and cost barriers to buying asthma medication (MED), seeing a health care provider for asthma (HCP), or any asthma care (AAC). Using SUDAAN, we performed survey-weighted difference-in-differences analyses, adjusting for demographics. Subgroup analyses were stratified by demographics. RESULTS: Our study population included 6445 participants from 25 states plus Puerto Rico. In 2015-2016 compared to 2012-2013, HIC was more common in ME jurisdictions (P < 0.001) but unchanged in non-ME jurisdictions. Adjusted difference-in-differences analyses showed ME was associated with a statistically significant 13.36 percentage-point increase in HIC (standard error = 0.053). Cost barriers to MED, HCP, and AAC did not change significantly for either group in descriptive and difference-in-differences analyses. In subgroup analyses, we noted variation in outcomes by demographics and 2014 ME status. CONCLUSIONS: We found ME significantly affected HIC among low-income adults with asthma, but not cost barriers to asthma-related health care. Strategies to reduce cost barriers to asthma care could further improve health care access among low-income adults with asthma in ME jurisdictions.