A study led by J. Tom Mueller, Ph.D., a research assistant professor at the University of Oklahoma, will examine the impact of Medicaid expansion across the United States to determine whether reduced mortality rates bear out across rural and urban communities as well as across ethnic or racial groups.
An estimated 82.8 million Americans currently receive health coverage through Medicaid. Jointly funded by states and the federal government, Medicaid provides health coverage to eligible low-income adults, children, pregnant women, elderly adults and people with disabilities.
The passage of the Affordable Care Act, signed into law in 2010, called for the expansion of Medicaid nationwide. After a Supreme Court ruling in 2012 determined that the decision to expand Medicaid benefits would be left to the states, participation in the expanded Medicaid program has grown slowly from 26 states participating in 2014 to 38 states and the District of Columbia participating by 2022.
Through the ACA, states participating in the Medicaid expansion program have the option to expand Medicaid coverage to adults with household incomes up to 138% of the federal poverty level.
Research has shown that from 2014-2018, mortality rates were reduced 3.6% more in states that expanded Medicaid than in states that did not. However, the impact of Medicaid expansion on health disparities remained underexamined.
“Medicaid expansion basically means that people at different income thresholds are eligible for Medicaid, which opens up a whole suite of health care options to people who otherwise wouldn't have been able to afford it,” Mueller said. “We have evidence that Medicaid expansion has reduced poverty and we have evidence that it has impacted health, but we don’t really have this kind of understanding on how it has related to disparities.”
“This project is looking at the impact of Medicaid expansion on disparities in mortality between rural and urban areas, and also then between different ethnic and racial populations within those areas, with the idea being that Medicaid expansion should have reduced mortality disparities,” he added. “Since poverty is such a dramatic social determinant of health, poverty reduction should be working as a mechanism for disparity reduction.”
The researchers will use data sets for the entire United States dating from before the ACA Medicaid expansion, 2008 through 2019, to reduce variables influenced by the COVID-19 pandemic. They plan to report their findings at the county level.
Mueller said in addition to insights on how Medicaid expansion may have impacted health disparities, “(The data) could also tell us information about the possible impacts of more broad scale universal health care options in the United States.”
Mueller, who holds faculty positions in the Department of Geography and Environmental Sustainability in the College of Atmospheric and Geographic Sciences, and the Department of Sociology in the Dodge Family College of Arts and Sciences, is working with collaborators at the University of Pennsylvania, McGill University and U.S. Census Bureau, as well as a board of consultants. The five-year project, “The Effect of Medicaid Expansion on Mortality Disparities and Poverty,” is funded by an estimated $1.5 million grant from the National Center on Minority Health and Health Disparities of the National Institutes of Health. Mueller is also a research fellow with OU’s Institute for Resilient Environmental and Energy Systems.