Under this Funding Opportunity Announcement (FOA), the National Heart, Lung, and Blood Institute (NHLBI) invites applications to support a comparison of the ability of two data sources, electronic health records and traditional prospective patient-based clinical and research data, to answer research questions regarding the natural history, longitudinal outcomes, and phenotypes of therapeutic response for pediatric pulmonary vascular disease (PVD).There will be one award for a Bioinformatics Clinical Coordinating Center (BCCC).Because PVD in children is rare and heterogeneous, the applicant will develop, implement, and evaluate the strengths and limitations of two data collection approaches to answer research questions regarding the natural history, longitudinal outcomes, and phenotypes of therapeutic response.The prospective data collection strategies proposed should include utilizing: 1) electronic health records (EHR) and 2) traditional prospective patient-based clinical and research data.Applicants should propose: 1) methods, plans, and expertise required to develop the two data sources; 2) at least three research pediatric PVD questions that the data collection strategies can address; and 3) a method to compare the usefulness of the two data sources to answer the research questions. This work will elucidate the value of EHR in answering real-world clinical management questions with the ultimate goal of improving health outcomes for children treated for PVD, and optimizing clinical trial design.The work will require multidisciplinary and multi-institutional team coordination that includes expertise in bioinformatics and computational science and clinical knowledge and access to pediatric patients with PVD.