Adapting and Testing a Youth Overdose Prevention Toolkit - PROJECT SUMMARY/ABSTRACT Overdose is now a leading cause of death among adolescents and young adults ages 12 to 24 (hereafter “youth”) in the US and Canada as a result of an increasingly toxic illicit drug supply. Evidence-based interventions to prevent overdoses exist but remain poorly adapted to the developmental needs of youth and have not been implemented in most pediatric healthcare settings. To fill these gaps, this study proposes a three-year community-engaged approach to adapting, producing, and pilot testing a written youth overdose prevention “toolkit” for use by clinicians in pediatric healthcare settings (e.g., hospitals, community clinics). The toolkit will be comprised of practical and easy to use guidance for delivering the following evidence-based core elements: naloxone and take-home drug testing strips, harm reduction education, and medications for opioid use disorder (MOUD; i.e., buprenorphine, methadone, or naltrexone). Our project will be conducted in Boston, MA, and Vancouver, BC, two locales that are highly impacted by the overdose crisis and have been instrumental in developing and disseminating world-leading youth substance use interventions. In both cities, there are currently significant efforts underway to improve access to overdose prevention and MOUD for youth in pediatric healthcare settings, allowing us to capitalize on existing infrastructures while also identifying how health systems differences and other important contexts may present unique barriers and facilitators to toolkit implementation. Our project will be guided by the ADAPT-ITT implementation science framework, with a focus on the Adaptation, Production, and Testing Phases. Across each phase, we will collaborate closely with youth with lived experience of substance use and their caregivers through the creation of Community Advisory Boards (CABs) in Vancouver and Boston. During the Adaptation Phase (Aim 1), we will conduct semi-structured qualitative interviews with youth, their family members and other caregivers, and pediatric clinicians to identify adaptations to the toolkit, rendering it practical and easy to use, developmentally appropriate and youth- and caregiver-centered. During the Production Phase (Aim 2), member checking by clinicians and CAB members will be used to elicit expert feedback on and to refine a written toolkit with local adaptations to the Boston and Vancouver settings. During the Testing Phase (Aim 3), a single-arm adaptive pilot study will be conducted with 40 youth (20 in Boston and 20 in Vancouver, followed for 3 months). Plan-Do-Study-Act cycles driven by quantitative survey measures and qualitative interviews with youth in the pilot study, as well as qualitative interviews with caregivers and toolkit providers (clinicians) will be used to further refine the toolkit. The product at the end of the R34 will be an optimized overdose prevention toolkit developed with extensive youth, caregiver, and clinician input, ready for rigorous R01 trial. This work squarely aligns with NIDA’s strategic priorities to improve the implementation of evidence-based strategies in real-world settings, and foster international collaborations to address health disparities among drug-using priority populations.