The widespread disparities in healthcare access among low- and high-income people declined significantly after the Affordable Care Act was implemented, according to a new study published Wednesday in Health Affairs.

The study finds that low-income people saw significant gains in insurance coverage because of the ACA, tightening the wide gap in healthcare access among people of different socio-economic status.

The study was published during a tumultuous week, with the push in the Senate to repeal and replace the ACA ultimately ending in failure for the GOP.

"There is a lot of misinformation about the ACA going around. (The study) clarifies who the beneficiaries are of the ACA, and the beneficiaries are poor and middle class Americans," said Jacob Bor, senior author of the report and an associate professor at the Boston University School of Public Health.

The study found that the gap between low-income people with insurance and high-income people with insurance declined from 31% to 17% in Medicaid expansion states, representing a 46% reduction. In states that opted not to expand Medicaid, the insurance gap between low-income and high-income people dropped from 36% to 28%.

Bor and his co-authors analyzed 2011-15 data from the Behavioral Risk Factor Surveillance System, a national survey conducted by the Centers for Disease Control and Prevention. Along with income differences, the authors looked at the responses to three questions from the survey to gauge healthcare access: if respondents had insurance coverage; if they had one person they considered their primary doctor or provider; and if there was a time in the past 12 months when they needed to see a doctor but didn't because of costs.

The authors found that in Medicaid expansion states, the number of low-income people who gained insurance coverage increased by 15 percentage points and the number of low-income people with access to a primary care provider increased by 7.7 percentage points.

Low-income people in states that didn't expand Medicaid experienced greater healthcare access with an 8.8 percentage point increase in insurance coverage and 4.4 percentage point increase in primary-care provider access. That growth was smaller than in Medicaid expansion states.

"Among the poor there is a geographic divergence," Bor said. "It's much better to poor in the expansion state now versus in a non-expansion state. (The ACA) widened the disparity."

The report also found that even before Medicaid expansion was implemented, poor residents in non-expansion states were 22% more likely to be uninsured than poor residents in expansion states.

"States opting out of the ACA Medicaid expansion thus compounded pre-existing access barriers," the authors wrote.

Overall, Medicaid accounted for about half of insurance gains. The other half was likely from insurance exchanges, federal subsidies and the individual mandate, according to the study.

A significant percentage of low-income people remained uninsured after the ACA was fully implemented in 2015, the study showed. About 35% of people in non-expansion states who earn below $25,000 a year were uninsured in 2015. In expansion states, about 21% of people who earn below $25,000 a year were uninsured.

That issue might stem from a lack of awareness of coverage options or political attitudes about the ACA that prevent people from seeking out its benefits, the authors said.

"Understanding people's reasons for not taking up insurance under the ACA will be important in designing policies to further reduce access gaps," the authors wrote.

Lawmakers also need to address insurance affordability, Bor said. Healthcare access has become more difficult even for those with insurance thanks to rising premiums and high-deductible health plans. Many insured people still report they don't seek care because they worry about costs.

"The discussions need to be more about how we can make insurance options better .?.?. and underlying medical care more affordable so coverage is more of value for people," Bor said.