The Effects of State Medicaid Expansion on Low-Income Individuals' Access to Health Care: Multilevel Modeling

This study aimed to examine how states' Medicaid expansion affected insurance status and access to health care among low-income expansion state residents in 2015, the second year of the expansion. Data from the 2012 and 2015 Behavioral Risk Factor Surveillance System were linked to state-level data. A nationally representative sample of 544,307 adults (ages 26-64 years) from 50 states and Washington, DC were analyzed using multilevel modeling. The results indicate substantial increases in health care access between 2012 and 2015 among low-income adults in Medicaid expansion states. The final conditional multilevel models with low-income adults who had income at or below 138% of the poverty line indicate that, after controlling for individual- and state-level covariates, those who resided in the Medicaid expansion states were more likely to have health insurance (OR=1.97, P<.001), have a usual source of care (OR=1.37, P<.01), and receive a routine checkup (OR=1.24, P<.01), and were less likely to not see a doctor because of cost (OR=0.66, P<.001) compared with low-income residents in non-expansion states in 2015. Moreover, the significant interaction terms indicate that adults living in non-expansion states with income below 100% of the poverty line are the most vulnerable compared with their counterparts in expansion states and with those with income between 100%-138% of the poverty line. This study demonstrates that state-level Medicaid expansion improved health care access among low-income US residents. However, residents with income below 100% of the poverty line in non-expansion states were disproportionately negatively affected by states' decision to not expand Medicaid coverage.