PROJECT SUMMARY/ABSTRACT Influenza infection causes high morbidity and mortality each year in the United States. Influenza vaccination of children is one of the most effective strategies for reducing the burden of disease among individuals and communities, yet coverage levels remain suboptimal. Hospitals are a promising setting for reaching a large number of high-risk children. Recent studies, however, indicate that many influenza vaccine-eligible children fail to receive this needed vaccine during hospitalization. Local data suggest that multimodal approaches leveraging health information technology may increase influenza vaccine uptake among hospitalized children. This project will build upon this existing evidence to establish a standardized pediatric inpatient influenza vaccination program that can be readily disseminated and successfully implemented across diverse health systems. In Aim 1 of this proposal, the study team will engage parents, nurses, providers and other key stakeholders from Seattle Children’s Hospital, Children’s Hospital Colorado, and Lurie Children’s Hospital of Chicago to create a best practice implementation guide for the inpatient influenza vaccination program. Core components will include creating a multidisciplinary leadership team, maintaining end-user engagement, utilizing novel electronic health record and data analytic tools, and enhancing evidence-based education and communication of parents, nurses, and providers. The program will be piloted at the 3 lead sites and refined as needed based upon evaluation metrics. In Aim 2, the study team will conduct a cluster randomized trial using a Sequential Multiple Assignment Randomized Trial adaptive design at 12 health systems nationally to test the effectiveness of the influenza vaccination program in improving influenza vaccination rates of hospitalized children. In the first intervention season, sites will be randomized to implement the standardized influenza vaccination program using the aforementioned implementation guide or usual care. In the second intervention season, the usual care sites and lower-performing intervention sites will be re-randomized to the standardized or intensified version of the program. The latter will include a learning collaborative, with monthly meetings of site leaders as well as one-on-one meetings with the study team to facilitate successful implementation. In the third intervention season, all sites will continue their influenza vaccination program to assess sustainability. In Aim 3, the study team will use mixed methods and the Reach, Effectiveness, Adoption, Implementation, and Maintenance (RE-AIM) framework to evaluate the program, including identification of key barriers, facilitators, and considerations for future dissemination. This information will be used to optimize and expand the program. This evidence-based program, which leverages novel clinical decision support tools in one of the most utilized electronic health record sys...