Abstract
BACKGROUND: Despite evidence that medications to treat opioid use disorder (OUD) are effective, most people who could benefit from this treatment do not receive it. This rapid review synthesizes evidence on current barriers and facilitators to buprenorphine/naloxone and naltrexone at the patient, provider, and system levels to inform future interventions aimed at expanding treatment. METHODS: We systematically searched numerous bibliographic databases through May 2020 and selected studies published since 2014. Study selection, data abstraction, coding of barriers and facilitators, and quality assessment were first completed by one reviewer and checked by a second. RESULTS: We included 40 studies of buprenorphine (5 also discussed naltrexone). Four types of patient and provider-level barriers to OUD medication use emerged-stigma related to OUD medications, treatment experiences and beliefs (positive or negative), logistical issues (time and costs as well as insurance and regulatory requirements), and knowledge (high or low) of OUD and the role of medications. Stigma was the most common barrier among patients, while logistical issues were the most common barriers among providers. Facilitators for both patients and providers included peer supports. Most administrator-identified or system-level barriers and facilitators fit into the category of logistical issues. We have moderate confidence in buprenorphine findings but low confidence in naltrexone findings due to the small number of studies. DISCUSSION: Stigma, treatment experiences, logistical issues, and knowledge gaps are the main barriers associated with low utilization of OUD medications. These barriers can overlap and mutually reinforce each other, but given that, it is plausible that reducing one barrier may lead to reductions in others. The highest priority for future research is to evaluate interventions to reduce stigma. Other priorities for future research include better identification of barriers and facilitators for specific populations, such as those with OUD related to prescription opioids, and for naltrexone use. PROTOCOL REGISTRATION: PROSPERO; CRD42019133394.