PROJECT SUMMART/ABSTRACT One-in-five children and adolescents in the United States (US) live in rural areas where they experience approximately two times the risk of suicide compared with their urban-residing peers. Despite having increased rates of mental and behavioral health conditions, less than half of rural-residing youth with these conditions receive necessary treatment, due in part to shortages of pediatric services and clinicians. Firearms are the most lethal means of suicide, and high rates of firearm ownership in rural regions contribute further to rural- urban disparities in youth suicide risk. Given barriers to community-based mental healthcare, youth with suicidal ideation and/or attempt increasingly present to emergency departments (EDs) for care. While several national organizations endorse safety planning (a brief intervention that involves identification of coping strategies, social supports, and lethal means restriction) in EDs as an evidence-based suicide prevention intervention, implementation in rural settings requires consideration of the cultural context as well as hospital and community resources. The overall goal of this project is to develop and implement a technology-aided approach to safety planning that will specifically address two social determinants of health – home safety and access to community mental healthcare – to decrease suicide risk in youth 12-17 years of age who present to rural EDs. To achieve this goal, investigators will: (i) conduct focus groups and interviews with rural-residing youth, their caregivers, clinicians, and community members to ascertain their priorities and perspectives about how to optimize safety planning, including lethal means counseling and community resource connections, in rural EDs; (ii) apply principles of human centered co-design to develop and test a youth- and caregiver-facing tablet-based digital intervention to guide safety planning, using mixed methods to investigate its feasibility, acceptability, and appropriateness, and to evaluate participant-reported self-efficacy to improve suicide-related coping and home safety (target mechanisms); and (iii) conduct a type 1 hybrid implementation-effectiveness study using a hospital-randomized stepped wedge design in four rural EDs to determine the effectiveness of this intervention compared to usual care for youth with suicidality, evaluating the extent to which outcomes are mediated by caregiver and youth self-efficacy, and assessing the reach, adoption, implementation and maintenance of the intervention using a mixed methods approach. Primary outcomes, measured one and three months following the ED visit, will include youth-reported suicide risk, evaluated using a validated instrument, and caregiver-reported access to firearms and medications within the home. These aims are directly aligned with the goals of this funding announcement to “develop, adapt, or implement intervention strategies addressing social determinants of healt...