Medicaid expansion linked to increased prescribing of buprenorphine for opioid use disorder treatment

States where Medicaid coverage was expanded under the Affordable Care Act have had a significant increase in prescribing of buprenorphine—a medication that plays an important role in addressing the opioid epidemic, reports a study in the April issue of Medical Care.

"Our findings suggest that Medicaid expansion has the potential to reduce the financial barriers to buprenorphine utilization and improve access to medication-assisted treatment of opioid use disorder," write Hefei Wen, PhD, of University of Kentucky College of Public Health, Lexington, and colleagues. The study also highlights the need for adequate numbers of physicians approved to prescribe buprenorphine.

Increased Buprenorphine Prescribing in States with Medicaid Expansion

The researchers analyzed trends in Medicaid-covered prescriptions for buprenorphine in states that did and did not expand Medicaid coverage under the Affordable Care Act. Buprenorphine is an "opioid partial agonist" that is effective in reducing opioid use, promoting abstinence, and aiding recovery.

Twenty-six states (and the District of Columbia) implemented Medicaid expansion in 2014. These states showed "upward trends" in Medicaid-covered buprenorphine prescriptions after the expansions. In contrast, buprenorphine prescribing did not significantly increase in states that did not expand Medicaid or expanded it after 2014.

After adjustment for other factors, Medicaid expansion was associated with a 70 percent increase in buprenorphine prescriptions. The increased number of prescriptions was accompanied by a 50 percent increase in Medicaid spending on buprenorphine.

In addition to Medicaid coverage, the number of physicians approved to prescribe buprenorphine was also an important contributing factor in access to buprenorphine. Because buprenorphine is a controlled substance, there are strict federal regulations on the qualifications of the physicians who can prescribe it for patients with opioid use disorder and the number of patients they can treat.

For each ten percent increase in the number of physicians approved to treat up to 100 patients in a given year, there was a 45 percent increase in buprenorphine prescriptions and a 31 percent increase in buprenorphine spending associated with the increase in the number of approved physicians. In areas with fewer approved prescribers, Medicaid expansion had a limited impact on buprenorphine prescribing.

Buprenorphine—the most commonly prescribed medication for opioid use disorder—is an important part of strategies to combat the ongoing opioid epidemic in the United States. Lack of health insurance coverage has been a major barrier to buprenorphine treatment. Medicaid expansion has the potential to increase availability of medication-assisted treatment to low-income groups with disproportionately high rates of opioid use disorder.

The new study provides evidence of a substantial increase in buprenorphine prescribing in states that expanded Medicaid. Further improvement is expected as states implement additional measures to facilitate access to Medicaid coverage and medication-assisted treatment for low-income patients with opioid use disorders

Dr. Wen and colleagues also emphasize the importance of physician prescribing capacity—increasing access to health insurance seems to have a limited impact on buprenorphine use in areas where there are not enough approved prescribers. The authors conclude, "Sufficient physician prescribing capacity is necessary for ensuring that Medicaid expansion achieves its full potential in improving buprenorphine utilization."