ABSTRACT This application seeks to develop improve and expand a multi-platform clinical decision support system (CDSS) in pulmonary arterial hypertension (PAH) for physicians, PHORA (Pulmonary Hypertension Outcomes Risk Assessment), which can be used in adults and children to: a) guide therapeutic decisions and b) optimize clinical trial design. We will achieve this goal by utilizing clinical trial data from several large databases of completed trials in PAH, ongoing adult and Pediatric PAH registries and Biobanks. The proposed aims co-create the CDSS with a multi-disciplinary group of specialties including: biomedical engineering, advanced PAH, computer science (machine learning/data mining), human computer interaction, and palliative care experts. Our intention is to engage all stakeholders to achieve consensus and thereby assure the acceptance of PHORA into practice. Successful completion of this project will lay the foundation for a prospective, multi-center META-Registry in which PHORA will be evaluated with respect to modeling best practice interventions leading to improved long-term patient outcomes. The ultimate aim is to disseminate this resource so as to improve the efficiency, efficacy, and cost-effectiveness of this treatment for PAH.