RESUMEN
BACKGROUND: A recent implementation science stepped-wedge trial of motivational interviewing (MI) in adolescent HIV clinics indicated variable degrees of implementation success. The present mixed-methods study analyzed trajectories of postimplementation MI competence scores and compared postimplementation qualitative interviews among the clinics with the highest levels of provider competency and the lowest levels of competency to further understand mechanisms of successful implementation. SETTING: Ten HIV clinics in the Adolescent Trials Network for HIV/AIDS Interventions. METHODS: This study used a sequential explanatory mixed-methods design. Continuous MI competency data from the parent study were structured with repeated measurements nested within providers nested within 10 sites. A mixed-effects regression model rank ordered the clinics by competence scores. Key stakeholders (N = 77) at the 10 randomized clinics completed a 1-hour qualitative interview at 12-month follow-up (immediately postimplementation). Using the phases of reflexive thematic analysis, interviews from the 3 highest competence clinics and the 3 lowest competence clinics were pragmatically analyzed. RESULTS: Thematic analysis suggested 3 central themes that influenced successful evidence-based practice (EBP) implementation. Organizational culture included the leadership, collective effort, and resources that influenced how the organization at large responded to the implementation intervention. Staff attitudes encapsulated individual providers' mindsets and attitudes about MI and the implementation intervention. EBP integration reflected the perception and use of MI by individuals and the organization as a whole. These themes and their subthemes are interconnected and exerted an influence on each other through the implementation process. CONCLUSIONS: Findings suggest additional implementation strategies to improve implementation of EBPs. Such mixed-methods research is critical to understanding the mechanisms of successful implementation of EBP and improving future implementation strategies.