Introduction: Understanding conditions in which interventions succeed or fail is critical. The PRimary care Opioid Use Disorders treatment (PROUD) trial, a cluster-randomized hybrid study, tested whether implementation of office-based addiction treatment supported by a nurse increased medication of OUD. Six health systems each provided two primary care (PC) clinics that were randomly assigned to implement the intervention or usual care. This secondary, exploratory study used an innovative mixed methods approach to understand contextual factors that consistently distinguished intervention clinics that increased OUD treatment from those that did not.

Methods: The study collected contextual information through field notes, health system debriefs, and nurse interviews. Rapid qualitative analysis using a template based on the Practical, Robust Implementation and Sustainability Model identified themes reflecting the external environment, recipients, and implementation. infrastructure. The study used qualitative themes to create binary factors reflecting barriers and facilitators potentially critical to implementation success and assigned clinics a factor value of 1 if present and 0 if absent. Two clinic-level outcomes were defined: 1) significant increase in patient-years of OUD treatment from baseline to two-year follow-up; and 2) high rate of OUD treatment at two-year follow-up (≥20 per 10,000 patient-years).