States that chose to expand Medicaid eligibility under the Affordable Care Act (ACA) have seen a greater decrease in uninsured rates among low-income patients with substance use disorders than states that did not expand Medicaid, according to the results of a recent study.

Following the 2014 ACA-mandated Medicaid expansion, 26 states and the District of Columbia allowed individuals with household incomes up to 138% of the federal poverty level to be eligible for health coverage under Medicaid. To assess the effect of this expansion on patients with substance use disorders, researchers from the Columbia University Mailman School of Public Health, and Columbia University Irving Medical Center analyzed 2008-2015 data from the National Survey on Drug Use and Health, focusing on Medicaid coverage among patients who had abused alcohol, cannabis, heroin, or cocaine.

The research team found that, between 2013 and 2015, the uninsured rate of low-income patients with substance use disorders decreased from 34% to 20% in states that had implemented the Medicaid expansion. Comparatively, the uninsured rate among these patients in nonexpansion states only decreased from 45% to 39% within this period.

However, the researchers also determined that, despite this increase in health coverage, there was no corresponding increase in substance use treatment within Medicaid expansion states.

“This may be because serious substance use problems tend to interfere with the ability to recognize the severity of drug use or perceive a need for treatment,” said study author Mark Olfson, MD, MPH, in a statement. “Although insurance coverage may be necessary, it is often not sufficient for people to seek help for their substance use problems.”

The study authors noted that, because low-income individuals face an increased risk of substance use disorders and are more likely to be uninsured, Medicaid expansion could be key to improving access to substance use disorder treatment, though further research is needed to better understand the ACA provision’s impact in this area.

“In light of persistently high levels of untreated substance use disorders, it will be important to track national trends in treatment patterns and outcomes, as clinical and public policy experience with the Medicaid expansion population matures over the next several years,” Dr. Olfson said, in a statement.

The results of the study are published in Health Affairs.

  1. Medicaid expansion states see rise in coverage for low-income adults with substance use disorders. Columbia University Mailman School of Public Health website. Published August 14, 2018. Accessed August 15, 2018.