PROJECT SUMMARY/ABSTRACT Prompt, high-quality emergency care saves lives. Despite this, formal trauma and emergency medical systems are rare in most LMICs. In this application, we propose to establish “Rwanda912” as an innovative mHealth platform to improve the existing prehospital system by accurately locating patients and facilitating communication between dispatch, ambulance and emergency triage staff. We will conduct this study in two phases: an R21 phase to establish baseline outcome measures, and develop and test the intervention, and an R33 phase to evaluate the intervention using a type 2 hybrid effectiveness/implementation design. In the R21 phase, we will establish baseline prehospital care time-based outcomes using a pilot software application to collect time data and exploratory clinical outcomes for trauma patients using the existing WHO Trauma Registry in Kigali, Rwanda. Then will develop the innovative Rwanda912 mHealth platform using the accelerated-create-to-sustainment (ACTS) model and assess for accuracy, reliability and stakeholder acceptability through a mixed-methods approach. In the R33 phase, we will implement and optimize the Rwanda912 platform for the clinical setting again using the ACTS model and then evaluate the implementation to determine acceptability, feasibility and fidelity using the Proctor framework. We will determine effectiveness based on an anticipated 10% reduction in total prehospital time with 90% power using a Type 2 hybrid implementation/effectiveness design. We will use an interrupted time series statistical design to evaluate the primary outcome based on one year of ambulance deployments pre and post implementation (n=6600). This project will leverage our established collaboration in this setting, foster mHealth development and research capacity in four Masters student, one PhD student and four software developers in Kigali. This will create a foundation for future funding applications to develop, implement and evaluate additional platform features such as a public interface. Study findings will serve as a model for developing a similar communication platform to support pre-hospital emergency care in other LMIC settings.