This is a Type 1 hybrid effectiveness-implementation study designed to evaluate the impact and feasibility of implementing low-threshold buprenorphine (BUP) treatment at syringe service programs (SSPs) in order to improve access to and retention in medications for opioid use disorder (MOUD) treatment among people with moderate to severe opioid use disorder (OUD). The study seeks to understand whether the low-threshold approach improves participant-level outcomes and how SSPs can successfully implement and sustain this model.
Study Design
The study uses a cluster randomized stepped wedge design, in which eight SSPs will be randomly and sequentially assigned to begin implementing the low-threshold BUP program until all sites have transitioned from the referral condition to the intervention condition. This design allows each site to serve as its own control and ensures equitable access to the intervention over time. The stepped wedge design also facilitates examination of temporal effects, while accounting for differences in local environments and SSP readiness for implementation.
Participants will be recruited across the eight SSPs in different geographic regions of the United States. SSPs will be selected to represent a range of community types (urban, suburban, and rural) and to reflect varying policy environments related to MOUD access.
Study Rationale and Background
Despite robust evidence that buprenorphine reduces overdose deaths and improves recovery outcomes, access to this medication remains limited, especially among people who use drugs and have difficulty navigating the healthcare system. Low-threshold buprenorphine models aim to reduce barriers by emphasizing same-day access, flexibility, and a treatment orientation that meets participants "where they are."
SSPs provide a trusted, nonjudgmental environment and are uniquely positioned to engage individuals who are at highest risk for overdose and least likely to access formal treatment. Integrating buprenorphine prescribing directly within SSPs could substantially expand access to life-saving treatment in community settings.
Study Objectives
Primary Objective:
To evaluate the effectiveness of low-threshold BUP treatment at SSPs compared to treatment as usual (TAU) for increasing 3-month retention in buprenorphine treatment.
Secondary Objectives:
Assess buprenorphine adherence, additional OUD treatment outcomes, and health-related quality of life.
Examine the cost-effectiveness of implementing low-threshold BUP at SSPs from both payer and societal perspectives.
Characterize implementation outcomes-adoption, acceptability, appropriateness, feasibility, reach, fidelity, and sustainability-across diverse SSP settings.
Exploratory Objectives:
Explore participant-level moderators (e.g., polysubstance use, co-occurring mental health conditions, housing status, rurality) that may predict outcomes or differential intervention effects.
Identify contextual determinants (organizational capacity, policy environment, leadership engagement) associated with successful SSP implementation.
Study Procedures
Participants will complete study assessments at baseline, 1 month, 3 months, and 6 months post-enrollment. Measures will include substance use patterns, treatment engagement, overdose events, hospitalizations, and self-reported recovery activities. Laboratory-confirmed urine drug screens will be used to verify buprenorphine adherence.
Pre-implementation (Treatment-as-Usual) Prior to implementing the low-threshold BUP model, SSPs will provide standard care, which includes referral to community MOUD providers for BUP treatment.
Post-implementation (Low-Threshold BUP Program) Once implementation begins, SSPs will offer onsite BUP treatment directly through trained prescribers and peer outreach workers. Clients identified as eligible and interested will receive a medical evaluation from a study clinician (SC), including assessment for contraindications, education on BUP use, and initiation via home induction or observed dosing as appropriate.
Follow-up visits will occur approximately every 4 weeks for 6 months and include focused psychosocial counseling, urine drug screening (when requested by the study clinician), and continued prescription management. Both in-person and telehealth models may be used to enhance accessibility. Participants may use any FDA-approved formulation of buprenorphine, including injectable long-acting formulations, based on shared decision-making between study clinician and participant.
Implementation Facilitation Strategy
To support successful and sustainable adoption of the low-threshold BUP model, the study's Lead Node (LN) will develop and deliver an Implementation Facilitation Package. This package will include:
Structured training for SSP staff and clinicians on low-threshold buprenorphine principles and program logistics.
Coaching on identifying a site champion, hiring or engaging a prescriber, and establishing clear protocols for medication management.
Ongoing facilitation meetings between the LN and SSP implementation teams (champion, prescriber, peer outreach worker) to troubleshoot challenges, monitor fidelity, and adapt workflows.
Tools for tracking and sustaining reach, fidelity, and acceptability over time.
Hypotheses and Analytical Approach
The central hypothesis is that embedding low-threshold buprenorphine treatment within SSPs will improve engagement and retention in MOUD compared to standard referral pathways. Analyses will use mixed-effects regression models accounting for site-level clustering and time effects. Effectiveness analyses will focus on 3-month retention as the primary outcome, with sensitivity analyses at 6 months. Cost-effectiveness analyses will use quality-adjusted life years (QALYs) as the main effectiveness measure.
Implementation analyses will use the Consolidated Framework for Implementation Research (CFIR) and Reach, Effectiveness, Adoption, Implementation, and Maintenance (RE-AIM) frameworks to identify determinants, measure outcomes, and map facilitation processes. Qualitative interviews with staff and participants will complement quantitative metrics, offering a comprehensive understanding of how and why the intervention succeeds or encounters barriers.
Expected Impact
This study addresses a critical public health need by testing a scalable, community-driven model of OUD treatment. If the low-threshold SSP-based buprenorphine program is found to be effective and cost-efficient, the Implementation Facilitation Package developed through this study will serve as a replicable framework for dissemination to SSPs or other community-based settings nationwide. The findings have the potential to directly inform national strategies for expanding access to evidence-based treatment, reducing overdose deaths, and promoting patient-centered care.