Project Summary/Abstract Suicide is a leading cause of death for individuals 10-24. Crisis counseling is a widely utilized intervention that can, in principle, reduce the incidence of suicide. Text-message-based crisis counseling, which can be delivered by smart phone, may be more accessible to teens and young adults than conventional, telephone- based systems. In recognition of this, a consortium of stakeholders in Utah promoted the development of the SafeUT crisis text-messaging app, which has been available to teens and young adults throughout the state since 2017. At present, SafeUT handles over 2300 crisis encounters, or “chats”, per month. We hypothesize that SafeUT has had measurable effects on critical mental health outcomes, such as emergency room visits for suicidal behavior, hospitalizations for suicidal behavior, and suicide death, for youth throughout the state. To evaluate this hypothesis, we will utilize geographically-informed statistical methods to measure the distribution of these outcomes across Utah and how they change over time in association with SafeUT use. To facilitate causal inferences, we will compare differences in outcomes before and after SafeUT implementation in Utah to differences in these outcomes in Colorado over the same period. We also have access to several additional key data sources—all unique to Utah—that represent mental health outcomes for youth within the state. First, through the Utah Population Database, we have access to the Utah Department of Health Healthcare Facility Database and the All Payer Claims Database: the former allows us to obtain information about youth hospitalizations and emergency room visits for all causes including mental health crises while the latter affords us access to information related to youths’ utilization of outpatient mental health and primary care appointments. Data for hospitalizations, emergency room visits, and outpatient visits are available to us for Colorado through the Colorado All Payer Claims Database. Additionally, we have an established relationship with the Utah state Office of the Medical Examiner which has curated a database of geolocated suicide deaths. Using these unique and powerful resources, we will first (Aim 1) evaluate demographic factors associated with SafeUT utilization in census blocks and (at a different level of analysis) school districts throughout the state. Simultaneously, we will (Aim 2) assess the effect of SafeUT implementation on emergency room visits, hospitalizations, and outpatient mental health visits for youth (ages 10-24) in Utah compared to Colorado. Finally, we will (Aim 3) assess the effect of SafeUT implementation on suicide death in Utah compared to Colorado. Ultimately, findings from our studies will facilitate alterations in SafeUT to improve service delivery and inform suicide prevention efforts throughout the country.