Emergency Medical Services (EMS) are an essential public resource that operates at the front lines of the healthcare system for Americans during their most vulnerable times. More than 1.8 million children are transported to an Emergency Department (ED) by EMS each year in the US, and approximately 90,000 need immediate intervention and stabilization by EMS providers. However, there are significant deficiencies in the safety and quality of care. We have found that critical pediatric patients have severe adverse safety events in 23% of calls. Children with respiratory failure requiring endotracheal intubation and children with cardiac arrest, arguably two of the highest risk and complex medical conditions, experience severe adverse safety events up to 60% of the time. Rural areas experience even greater challenges to quality pediatric prehospital care. It is vital for our EMS system to have a high level of readiness for pediatric emergencies, though serious gaps remain. One major gap is that there is currently no validated means to evaluate EMS agency readiness for pediatric emergencies. Such a metric would provide vital data on the current status of our system while empowering leaders and policymakers with information needed to guide resource allocation. Recent studies have found that hospital-based EDs with the highest readiness scores have more than threefold lower mortality rates for children with critical illness and trauma than the least ready EDs. Having a pediatric emergency care coordinator has also emerged as one of the key elements of ED readiness. Recently, the first technical report on pediatric readiness in EMS was published, which has created a starting point for scientific investigation that will enhance policymakers' efforts. Our overall goal is to improve the delivery of safe and high-quality prehospital care for children that maximizes outcomes. This study will expand on the previous methods used to measure readiness in hospital-based EDs to rigorously evaluate factors that improve pediatric readiness for EMS agencies and health outcomes for children. We will incorporate a positive deviance framework to ensure we develop a broad understanding of readiness from the perspective of field providers. The specific health outcomes we will evaluate include occurrence of adverse safety events during EMS care, as well as hospital outcomes specific to the diseases we will evaluate. The EMS system is positioned to improve outcomes for medical conditions that require immediate stabilization, such as seizures, trauma, cardiac arrest, and respiratory failure, which are our areas of focus. The specific aims of the study are to 1) derive a score that reflects the readiness of an EMS agency to care for critically ill children using a modified Delphi process among subject matter experts, 2) evaluate and refine the score developed in Aim 1 using empiric real-world data and patient outcomes including adverse safety events from both urban and rural ar...