Abstract
<title>Abstract</title> <p> <bold>Background</bold> Many patients with opioid use disorder (OUD) could benefit from long-acting injectable buprenorphine (LAIB), but it is not broadly available. This study examined the implementation of LAIB in three clinics (one primary care and two “low-threshold” clinics at syringe services programs (SSP)). Objectives were to identify implementation determinants (i.e., barriers and facilitators) at the organization, staff, and patient levels to inform development of tailored implementation strategies for each setting. <bold>Methods</bold> Researchers conducted semi-structured, qualitative interviews with staff (N = 23) and people with OUD who had lived experience with buprenorphine (N = 15) during early LAIB implementation at one primary care and two low-threshold clinics in New York City. Meeting notes from multidisciplinary clinical implementation working groups with staff (N = 27) served as an additional data source. Qualitative data collection and subsequent rapid qualitative analysis focused on implementation determinants by CFIR domain: the Innovation (LAIB), Individuals (staff and people with OUD), Inner Setting (organizational factors), and Outer Setting (external to where implementation is taking place), and recommendations for developing implementation strategies. <bold>Results</bold> In the Individuals domain, although staff were generally enthusiastic about implementing LAIB, they lacked comfort in counseling about LAIB, which necessitated tailored training and ongoing support. People with OUD expressed a need for detailed information about LAIB (e.g., side effects, withdrawal experiences, duration of effect) and suggested a peer messenger as an information source. Strong leadership support, clinical champions, and prior experience with sublingual buprenorphine helped overcome challenges in the Inner Setting. In the Outer Setting, the requirements to obtain LAIB from specialty pharmacies and federal regulations regarding controlled substance storage posed challenges for clinics. <bold>Conclusions</bold> In examining early implementation of LAIB in primary care and low-threshold clinics, multi-level barriers were identified as targets for implementation strategy development, including staff training needs, pharmacy access, and regulatory requirements. Favorable staff attitudes, strong leadership support, and local clinical champions helped overcome implementation barriers. These results can guide clinics in choosing implementation strategies and strengthen readiness for successful integration of LAIB. </p>