PROJECT SUMMARY/ABSTRACT This K23 award is for Dr. Michael Incze, a general internist, addiction medicine physician, and emerging clinician-investigator with expertise in leading interdisciplinary programs to improve the integration of substance use disorder (SUD) treatment into primary care settings. To study the implementation of novel models to support transitions to longitudinal SUD and primary care after a medical hospitalization, this K23 will allow Dr. Incze to acquire key skills in four career development areas: 1) implementation science methods for designing and evaluating SUD care interventions across care settings, 2) designing and conducting clinical trials with vulnerable groups, 3) qualitative evaluation of intervention implementation, and 4) leading an interdisciplinary research team. Dr. Incze has assembled a team of mentors and advisors with expertise in implementation science, clinical trial design, and research with vulnerable populations to guide his training and research program. His Department is fully committed to his success and growth as an early-stage clinician investigator. The overdose public health crisis continues to account for tens of thousands of preventable deaths each year. Despite the urgency of this crisis, less than half of people with SUD receive any treatment. Medical hospitalizations are common among people with SUD and represent crucial opportunities to engage them in SUD treatment. Ensuring seamless linkage to longitudinal SUD and primary care after hospital discharge is a fundamental aspect of hospital-based SUD treatment; however, multiple barriers may interrupt these transitions of care, and there are no rigorously studied models to support patients with SUD during these high- risk events. Primary care may play a central role in addressing this care gap, given its geographic reach, team- based care models, expertise in care coordination, and focus on chronic disease management. However, primary care clinicians need mentorship and support to adopt SUD treatment into practice. Dr. Incze’s objective is to use implementation science methods to design, refine, and conduct a pilot clinical trial of a primary care-based Interdisciplinary Addiction Care Transition (IntACT) team to support care transitions between hospital and primary care settings for patients with SUD. His proposed Specific Aims (SA) are: SA1) Identify key stakeholder perspectives on the optimal role, activities, and implementation of the IntACT intervention; SA2) Design and refine a protocol for the implementation of the IntACT Intervention using the PRISM and RE-AIM frameworks; and SA3) Test the feasibility, acceptability, and preliminary effectiveness of the IntACT intervention through a pilot feasibility clinical trial. The proposed research is significant because it aims to increase linkage to longitudinal primary care and SUD treatment during the high-risk period following medical hospitalization. It is innovative because it leverages stakeholder engagement and implementation science frameworks to develop and evaluate a novel, potentially scalable, primary care-based intervention to support post-hospitalization care transitions and primary care/SUD treatment access for individuals with SUD.

PROJECT NARRATIVE The overdose public health crisis continues to account for tens of thousands of preventable deaths each year, making the design and implementation of novel substance use disorder treatment strategies with the potential for broad reach a public health imperative. Medical hospitalizations are common among people with substance use disorders and represent important opportunities to engage them in treatment; however, hospital-based models of substance use disorder treatment must optimally include robust strategies to support transitions to longitudinal primary care and substance use disorder treatment after discharge. An interdisciplinary, primary care-based team designed to support post-hospitalization care transitions represents a novel and scalable model to ensure linkage to and retention in care for patients with substance use disorders following medical hospitalization.