PROJECT SUMMARY Opioids were involved in almost 47,000 deaths in the U.S. in 2018—nearly the number who were killed in the entire Vietnam War. Injection opioid and methamphetamine use are driving up rates of HIV and HCV infection. The opioid crisis has similarly affected Canada and Mexico, leading to a call for a North American approach to addressing the opioid crisis. Simulation models provide a structured environment for decision makers to compare the predicted effects of proposed policy alternatives over an extended time horizon on population- level outcomes such as overdose, HIV, and HCV. The COVID-19 pandemic has provided evidence of the utility of using simulation models for public health decision making. Several public agencies are currently funding opioid simulation modeling efforts in North America, including NIDA, CDC, FDA, the Canadian Institutes of Health Research (CIHR), and Canadian provincial agencies. Our overarching goal is to improve the speed, validity, effective knowledge translation, and

PROJECT NARRATIVE Opioids were involved in almost 47,000 deaths in the U.S. in 2018, injection opioid and methamphetamine use are driving up rates of HIV and HCV infection, and the opioid crisis has also affected Canada and Mexico. We propose to bring together leaders in opioid simulation modeling of fatal overdose, HCV, and HIV in North America together with policy makers in order to address issues of model design, data availability and integrity, and knowledge translation. The proposed workshops will leverage currently funded modeling efforts through the NIH and other agencies, to provide the opportunity for modeling groups to swiftly develop and share best practices, and to further the science to maximize public health and policy impact.