PROJECT SUMMARY Children with medical complexity (CMC) are uniquely vulnerable to medication errors and adverse drug events because of their extreme polypharmacy, underlying medical fragility, and reliance on complicated medication schedules and routes. CMC have 5 times higher odds of an adverse drug event leading to an Emergency Department (ED) visit than other children. Over 1 of 50 CMC ED visits are due to adverse drug events, and 38% of CMC ED visits for adverse drug events result in hospital admission. Having accurate knowledge to accurately give high-risk medications is an absolute requirement for safe medication management. Prior work observed that medication administration accuracy, i.e., knowing indication, formulation, dose, frequency, and route of administration, was successfully described by fewer than half of CMC caregivers. Low medication administration accuracy leads to adverse drug events, including potentially preventable hospitalizations, emergency department visits, and morbidity. Currently, no tools exist to support families of CMC to ensure high medication administration accuracy across their network of “secondary” caregivers involved in CMC daily care (e.g., family, in-home care professionals, school caregivers, etc.). To address these critical unmet needs, we will create a mobile health (mhealth) platform, Medication Safety @HOME (MedS@HOME) to improve CMC medication safety by supporting standardized medication management across the caregiving network. We anticipate that MedS@HOME will increase medication administration accuracy and reduce medication-related adverse events, and ultimately improve chronic care management through the creation and promotion of standardized medication management practices across the caregiving network. To achieve this goal, we propose to conduct the following aims: 1) Design the MedS@HOME intervention through participatory co- design with stakeholders in a parallel design process with three design teams: one with primary CMC caregivers, one with secondary caregivers, and one with experts in medication safety and CMC clinical care; 2) Evaluate the effectiveness of MedS@HOME on medication administration accuracy of high-risk medications (e.g., antiepileptic drugs, opioids) in a randomized controlled trial, testing the hypothesis that medication administration accuracy is improved for primary and secondary caregivers with use of MedS@HOME. Completion of the aims will result in a scalable mhealth intervention that improves medication safety for CMC across the caregiving network. MedS@HOME, when perfected, can improve medication safety and chronic care management across the wide range of populations that depend on caregiving networks.