The Affordable Care Act (ACA), commonly known as ObamaCare, has been evaluated in a new research study regarding its impact in Americans living with chronic diseases, like chronic kidney disease (CKD), and was found to have been effective at providing insurance coverage and improving access to medical care for many, but not for all those in need.

The study, led by Harvard Medical School researchers, is titled “Coverage and Access for Americans With Chronic Disease Under the Affordable Care Act: A Quasi-Experimental Study,” and was published in the Annals of Internal Medicine.

Patients of chronic diseases have higher healthcare needs and may face considerable consequences if they can’t access affordable medical care.

“Patients with chronic diseases need to get regular medical care and take medications daily to prevent serious complications,” Elisabeth Poorman, the study’s author and a primary care physician at the Cambridge Health Alliance, said in a press release. “For the millions with a chronic disease that got coverage under the ACA, it is a big deal. But it is really unfortunate that so many chronically ill Americans remain uncovered despite the ACA.”

Nationally representative data from 606,277 adults ages 18 to 64 with chronic diseases was assessed in 2013 and in 2014, the year after most major reforms were put in place. The ACA was signed into law in 2010 and was upheld by the Supreme Court in June 2012.

Coverage for the chronically ill increased the most in states that expanded Medicaid, from 83 to 89 percent. In states that declined the expansion coverage, coverage increased from 77 to 81 percent. After full implementation, the percentage of people living with chronic diseases who had insurance coverage reached the highest in Massachusetts (95 percent) and the lowest in Texas (74 percent). In West Virginia, chronic disease patients saw the biggest gains, with a 12 percent increase.

Racial and ethnic disparities in coverage were also decreased under the ACA; however, one in seven of those with chronic diseases still lacked coverage, including one in five chronically ill blacks and one in three Hispanics.

These findings suggest that Medicaid expansion played a key role in improving the lives of patients of chronic diseases, even though this might not have affected all patients in the same way. Overall, Americans with chronic diseases were found to be less likely to forgo a doctor visit due to cost and more likely to go on their routine check-ups after the ACA.

“Repealing the ACA without an equivalent replacement would strip coverage from millions of chronically ill Americans, spelling disaster for many of them,” said Danny McCormick, the study’s senior author and also a physician at Cambridge Health Alliance and an associate professor at Harvard.

“A comprehensive Medicare-for-All plan is the replacement for the ACA that’s most likely to provide coverage and good access to care for everyone with a chronic illness,” he said. “Polls show that such reform is popular with the Americans people — even among those favoring repeal of the ACA — but unfortunately, the politicians that control the White House and Congress are unlikely to embrace it.”