Rhode Island has been one of the U.S. states hit hardest by the opioid epidemic. Its per capita opioid-related mortality rate has been above the national average every year since 2000, and it exceeded that average by 70% or more in the years 2016 through 2018. However, after rising sharply from 2012 to 2016, the death rate in the state levelled off and began to decline before the onset of the COVID-19 pandemic, during which Rhode Island, like many other states, has seen a resurgence in opioid-related deaths.

Findings from a new report from the Federal Reserve Bank of Boston focusing on Rhode Island indicate that the state’s Medicaid expansion led to an increase in the use of medication-assisted treatment, or MAT, for opioid use disorder.

“The Medicaid Expansion and the Uptake of Medication-assisted Treatment for Opioid Use Disorder: Evidence from the Rhode Island All-payer Claims Database, 2012–2018,” by Boston Fed senior economist and policy advisor Mary A. Burke and senior policy analyst Riley Sullivan, uses Rhode Island’s all-payer claims database to study the state’s progress in expanding access to MAT for patients with opioid use disorder, known as OUD.

MAT involves administering methadone, buprenorphine, or naltrexone in conjunction with behavioral therapy. Rhode Island’s all-payer claims database, HealthFacts RI, captures in any given month the medical treatments (including drug prescriptions) received by most Rhode Island residents who are covered by health insurance, including Medicaid.

Rhode Island is one of the many states that granted a broader range of residents access to Medicaid in 2014 following passage of the Affordable Care Act, which, like the recently passed American Rescue Plan Act, contained financial incentives for states to expand Medicaid. (Twelve states have not yet adopted the Medicaid expansion.) Low-income childless adults were among the groups who became eligible for Medicaid when Rhode Island expanded its program.

“The Medicaid expansion was especially important in helping more OUD patients in Rhode Island gain access to MAT, as the population targeted by Medicaid is particularly susceptible to OUD and because Rhode Island’s Medicaid program offers generous coverage for MAT and related substance abuse treatment services,” the Boston Fed report’s authors write.

The report finds that the rate at which all health insurance enrollees in Rhode Island received MAT doubled between 2012 and 2018 – the study’s observation period – while the OUD rate also doubled. This suggests that the growth in the MAT rate just kept pace with the need for treatment. However, when the authors analyze the trends for Medicaid enrollees and non-Medicaid enrollees separately, they find that the state appears to have made much greater progress in treating OUD with MAT among Medicaid patients. Between 2012 and 2018, the MAT rate for non-Medicaid enrollees increased roughly 42%, and the OUD rate grew 79%. But among Medicaid enrollees, the MAT rate increased 76%, and the OUD rate rose only 50% during that period.

“An important caveat to these statements is that the observed OUD prevalence rate is an imperfect measure of the need for treatment, as many OUD cases go undiagnosed and the suitability of MAT varies across patients based on disease severity and other factors,” the authors write.

The report also finds that the largest single-year rise in the number of patients receiving MAT occurred in 2014 – when the Affordable Care Act and associated Medicaid expansion went into effect. That year, more than 80% of the first-time enrollees who received MAT were Medicaid enrollees, and they accounted for nearly 40% of the rise in the total number of MAT patients from the previous year.

According to the report, Rhode Island’s Medicaid expansion helped to increase the MAT rate not only because it extended health insurance to a population especially susceptible to OUD, but also because Medicaid enrollees have been much more likely than other health insurance enrollees to receive MAT, even after the higher OUD rate among Medicaid enrollees is taken into account. Throughout the study’s 2012–2018 observation period, the MAT rate was at least 4.6 times greater among Medicaid enrollees than among non-Medicaid enrollees, and it peaked at more than six times greater in 2015.

“Our analysis shows that expanded eligibility for Medicaid insurance has helped large numbers of Rhode Islanders gain access to medication-assisted treatment since 2014,” the authors write. “These results agree with evidence from previous studies that Medicaid represents an important source of access to MAT and that the Medicaid expansion that accompanied the Affordable Care Act helped to bring evidence-based treatments to a greater share of the population affected by OUD.”

Read the full report.

Mary A. Burke is a senior economist and policy advisor in the research department at the Federal Reserve Bank of Boston. Full bio here.

Riley Sullivan is a senior policy analyst in the Boston Fed research department. Full bio here