Background: Chronic pain is a major public health problem and a leading cause of disability among Veterans. As such, addressing chronic pain and opioid safety remain top priorities of the Veterans Health Administration (VHA). While long-term opioid therapy (LTOT) for chronic pain is common, harms of continuing LTOT may outweigh benefits for many patients. When this is the case, guidelines recommend tapering or discontinuing opioids; however, recent evidence also highlights the potential harms associated with tapering or discontinuing opioids. Furthermore, guidelines emphasize the importance of optimizing non-pharmacologic pain treatment (NPT) options, yet clinicians report several barriers to doing so. For these reasons, managing chronic pain among patients prescribed LTOT is often challenging and there is a critical gap in evidence-based strategies to overcome these challenges. To address this gap, the Veterans Pain Care Organizational Improvement Comparative Effectiveness (VOICE) study compared two models of care to improve pain and support opioid tapering. This 10-site pragmatic trial enrolling from 2017-2021 randomized 820 veterans with moderate to severe pain treated with LTOT to two active collaborative care interventions with on average ten study contacts over a 12-month period; VOICE did not have a control group or usual care condition. While both groups improved, the VOICE study found no differences in pain-related outcomes or changes in opioid dose between its two interventions. Thus, a lack of control condition leaves unanswered questions about the impact of these interventions as compared to usual primary-care based VHA pain care. Methods: To address these unanswered questions and help inform VA’s decisions about pain care resource deployment, our overarching aim is to emulate a 3-arm, randomized controlled trial. Emulated trials draw on observational data to emulate the design characteristics of a randomized trial when randomized trial data is not available. In the proposed emulated trial, we will examine the impact of VOICE’s two active interventions against a retrospectively matched “external” usual care control group using a propensity-based matching approach. This control group will be drawn from the Evaluating Prescription Opioid Changes in Veterans (EPOCH) study, a national longitudinal prospective cohort launched in 2016 and funded by VA Health Services Research & Development (HSR&D) to understand effects of changes in opioid prescribing practices on Veterans treated with LTOT for chronic pain. EPOCH’s large, nationally representative sample (N=9253), nearly identical timeframe, inclusion criteria and study populations, and similar patient-reported and electronic health record outcomes to VOICE make it a very compelling source of patients prescribed LTOT receiving usual VHA pain care. Specific Aims: By emulating a three-arm RCT and examining outcomes including pain-related interference, opioid dose, quality of life, and engage...