Did the Affordable Care Act Affect Access to Medications for Opioid Use Disorder among the Already Insured? Evidence from the Rhode Island All-payer Claims Database.
Medicaid has been cited as an important source of access to medications for opioid use disorder (MOUD), as the populations targeted by Medicaid tend to show a high prevalence of opioid use disorder (OUD) and many state Medicaid plans offer generous coverage for buprenorphine or methadone or both of these OUD medications. Previous research suggests that state Medicaid expansions implemented starting in 2014 under the Patient Protection and Affordable Care Act (ACA) helped large numbers of OUD patients gain access to MOUD that was previously lacking. However, a potential drawback of Medicaid expansion involves the impact on individuals who are already enrolled in Medicaid when these policies are implemented. The concern is that these patients’ access to care could be impeded, as new enrollees would place added demands on a limited supply of providers of MOUD.
Using the all-payer claims database for Rhode Island (HealthFactsRI) spanning the period January 2012 through December 2015, this paper tests directly for whether incumbent (pre-2014) Medicaid enrollees in Rhode Island experienced any systematic changes in their use of buprenorphine after January 2014, the month in which the state implemented the ACA and its associated Medicaid expansion. The paper also examines changes in the number of buprenorphine prescribers in Rhode Island and in their patient loads, comparing the numbers from before and after January 2014 to gain additional insights into the ACA’s potential implications for incumbent patients.