Assessing the Impact of Emergency Medical Services System Changes to Overdose Response: The ORCID Study - The public health crisis of overdose continues in King County, WA, with over 500 deaths in 2020, 700 in 2021, and rates remaining subsequently high. Emergency Medical Services (EMS) providers are often the first point of contact for individuals experiencing overdose and play a critical role in connecting people who use drugs (PWUD) to care. In partnership with PWUD, EMS leadership, and community stakeholders, our interdisciplinary team collected pilot data and co-designed EMS-delivered interventions aimed at reducing negative perceptions of PWUD and improving access to evidence-based care. These interventions are being implemented as the EMS Overdose Prevention Project (EMS-OPP), which includes EMS provider training in reducing negative perceptions of PWUD and trauma-informed care, a naloxone leave-behind program with fentanyl test strips, and warm hand-offs to follow-up teams for substance use treatment. King County EMS plans to iteratively adopt EMS-OPP, with a goal of 90% team participation by 2026. To evaluate the impact of EMS-OPP, we are conducting a hybrid implementation-effectiveness study using a concurrent triangulation mixed methods design. Our revised study assesses whether EMS-OPP improves overdose-related outcomes for the entire population of overdose survivors. Specifically, we aim to: Evaluate the effect of EMS-OPP on patient-level experiences (e.g., perceptions of EMS care) and health outcomes (e.g., linkage to buprenorphine treatment) through a prospective cohort study of non-fatal overdose survivors (Aim 1); Understand the experiences of overdose survivors with EMS-OPP using in-depth qualitative interviews (Aim 2); and Examine the population-level impact of EMS-OPP on outcomes such as follow-up care using an interrupted time series design with switched replication (Aim 3). This study capitalizes on a unique moment in the opioid crisis, as EMS systems expand their scope and capacity. Findings will inform future EMS interventions and data linkage strategies to support long-term surveillance of overdose outcomes. Dissemination will include community-oriented products (e.g., zines, artistic data posters), policy briefs, conference presentations, and peer-reviewed publications.
