Adapting the HOPE Online Support Intervention to Increase MAT Uptake Among OUD Patients - In a randomized controlled trial, with 3, 6-month and 1-year follow-up, this application seeks to assess the effectiveness of using an online peer support community intervention to increase MOUD initiation and sustainment among participants with opioid use disorder (OUD) who are recruited online. On average, 130 people die in the United States each day from opioid overdoses, making the opioid crisis the country’s top public health concern (1,2). Although effective FDA-approved medication for opioid use disorder (MOUD) is available for patients with opioid use disorder (OUD), including buprenorphine and injectable naltrexone, only a small fraction of those who would benefit from these medications use them. There are a number of reasons for low MOUD use, including lack of insurance; knowledge, among both providers and patients; MOUD-related stigma; and social norms (e.g., people would be more willing to use MOUD if their peers were also using MOUD). Innovative methods, especially those that address multiple levels (e.g., the individual, culture, and society/community) are needed to increase MOUD use among individuals with OUD. Online peer-led support interventions might be particularly effective at increasing MOUD uptake because they can leverage peers to widely and rapidly scale changes in social norms (e.g., interest in using MOUD) throughout people’s natural, real-world, virtual environments. For example, the Harnessing Online Peer Education (HOPE) intervention, an online peer support community intervention designed to reduce stigma and increase health behavior change, has been shown to be effective at changing health behaviors among stigmatized populations, such as for HIV. Specific to opioid-related issues, our team recently found the HOPE intervention to be a feasible and acceptable method of reducing risk for prescription opioid misuse among chronic pain patients on opioid therapy. However, no research has studied whether online support interventions, such as HOPE, might be effective in increasing MOUD requests, uptake, and sustainment among OUD patients. It is therefore critical to evaluate these social normative/behavioral technology methods to reduce the increasing rate of opioid overdose. In this study, we seek to explore whether and how the HOPE online support intervention might be adapted to increase MOUD initiation and sustainment among participants with OUD, assess the effectiveness of using the intervention to increase MOUD requests among OUD participants recruited online who are not using MOUD, and using an implementation science approach determine the relationship between online community data and behavior change.