A new data analysis has found that Medicaid patients in states that expanded the public insurance program are more likely to be prescribed buprenorphine — a treatment drug for opioid addiction that gives patient a better shot at recovery.

The analysis, conducted by the Urban Institute, a Washington, D.C. think tank, analyzed the number of buprenorphine prescriptions that were covered under Medicaid between 2011 and 2018.

It found that states who expanded Medicaid under the Affordable Care Act after 2014 — adding thousands to the public insurance rolls — covered buprenorphine prescriptions at a far higher rate than states that did not expand the program.

Buprenorphine is an opioid-based treatment drug that helps curb cravings, prevent overdoses, and allow opioid users to get through the day without the fear of painful withdrawal. Expanding access to the drug has become a crucial component of many communities’ fight to reduce their overdose death rate.

The drug is not a panacea, the study suggested: Some of the states that expanded Medicaid and increased buprenorphine prescriptions — like West Virginia — still suffer from some of the highest overdose rates in the country.

But Vermont, which dramatically increased buprenorphine prescribing early on in the opioid crisis as part of a more comprehensive addiction treatment expansion, now has the lowest overdose rate in the New England region.

And some states that did not expand Medicaid, like Missouri, South Carolina, and Tennessee, have low rates of buprenorphine prescribing — and overdose rates higher than the national average, the study showed.

“For states that didn’t expand Medicaid, [expanding the program] is the most important thing they can do to increase treatment rates,” said Lisa Clemans-Cope, a principal research associate at the Urban Institute and the lead author of the analysis. “States that have already expanded should think about whether people can access treatment when they need it, and whether treatment is as effective as it can be.”

For example, she said, Pennsylvania’s buprenorphine prescription rate in 2018 was about 224 prescriptions for every 1,000 Medicaid enrollees above the age of 12 — well above the national average, but ranked below 12 other states.

Pennsylvania officials have been working to increase access to the drug for some time. The state health department has worked to eliminate prior authorizations on buprenorphine — a waiting period during which doctors had to obtain approval from an insurance company before prescribing the medication.

In Philadelphia, physicians have led an unofficial campaign to help more of their colleagues obtain the federal certification required to prescribe the drug. Earlier this year, after reporting that some 3,000 treatment slots in the city were still open, city health officials launched a campaign called “Bupe Works” to encourage more people to get started on the drug.

“There are a lot of things that factor into the barriers to getting treatment, and that can have to do with all kinds of regulations and rules about insurance, refill limits, and dosage restrictions — all kinds of things beyond just the medication [being available],” Clemans-Cope said. “The questions that are raised in this paper is that, even in expansion states, it looks like a lot of state Medicaid programs are falling short in meeting treatment needs.”