The Affordable Care Act (ACA) has helped to close the gap in health care access between residents of poor and higher-income households, a new report by Boston University School of Public Health (BUSPH) researchers shows.

In an article in Health Affairs, the authors examined national survey data of U.S. adults ages 18-64, collected by the Centers for Disease Control and Prevention, to determine the impact of the ACA on socioeconomic disparities in insurance coverage. They found that in states that expanded Medicaid, the gap in insurance coverage between residents of poor households (incomes of less than $25,000) and higher-income households (over $75,000) fell by 46 percent between 2013 and 2015. By contrast, in non-expansion states, the coverage gap fell by only 23 percent.

Income-related gaps in access to primary care providers and avoiding care due to cost also declined more in expansion states than in non-expansion states.

"Reducing health access disparities has been a subject of national debate since President Harry Truman proposed universal coverage in 1945," the authors said. "As we have shown in this analysis, the ACA substantially improved health insurance coverage and access to care for the poor and significantly reduced socioeconomic gaps in health care access in just two years."

The authors said that despite the substantial reductions in access gaps under the ACA, many residents with household incomes under $25,000 were still without coverage in 2015: 35 percent in non-Medicaid expansion states, and 21 percent in expansion states. In addition, in 2015, many low- and middle-income residents still reported avoiding care due to cost, the report said.

"In its first two years of full implementation, the ACA improved health care access for Americans in low-income households, people who were not college graduates, and the unemployed," the authors said. "The law's Medicaid expansion was responsible for about half of these gains. The ACA was associated with a substantial (but incomplete) narrowing of socioeconomic disparities in access, particularly in states that expanded Medicaid."

They said that more research is needed to determine whether existing access gains will translate into improved health outcomes and reductions in disparities, and to "monitor future trends in access disparities in a changing policy environment."

"The U.S. is an outlier among rich countries when it comes to our very large disparities in health care access between rich and poor," said senior author Jacob Bor, assistant professor of global health and epidemiology at BUSPH. "The ACA, where it was fully implemented, cut these disparities in half, bringing the U.S. much closer to our peers. Repealing the ACA, as proposed by President Trump and Republicans in Congress, would likely reverse these gains, exacerbating socioeconomic disparities in access."

Co-authors on the paper were Kevin Griffith and Leigh Evans, PhD students in health law, policy and management at BUSPH. Griffith said the U.S. had made "tremendous progress in health care access in just two short years, bringing us closer to other major nations."

However," he added, "we must stress that these gains are fragile. We would likely end up where we started if the ACA is repealed. Even without a full repeal, our political turmoil is injecting a great deal of uncertainty into the marketplaces, which could dissuade insurer participation and discourage enrollment."

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