Harnessing healthcare standards to construct a continuity of care knowledge graph

Abstract Background Standards are foundational to digital health innovation, supporting systems from electronic health records (EHRs) to personalized knowledge graphs. They ensure consistent structuring, exchange, and use of health data. Yet, the diversity and interconnected nature of standards spanning health informatics, messaging protocols, and web/IT frameworks are often overlooked. This lack of clarity hampers interoperability efforts. Patient data, created across various care settings, often remains siloed, limiting insights and cross-border collaboration. Methods This paper explores how different types of standards drive interoperability in digital health. We examined ISO 13940:2015, HL7 FHIR, SNOMED CT, RDF, ISO/IEC 21838-3:2023, and web APIs, analyzing their role in data harmonization. Based on these insights, we designed the Common Semantic Standardized Data Model (CSSDM), a conceptual framework to map diverse datasets to standardized vocabularies and ontologies, creating semantically enriched, machine-readable data. We applied CSSDM in Irish and Spanish care contexts to build a personalized knowledge graph. Results CSSDM effectively integrated diverse health data sources into a unified knowledge graph. Using standardized semantics and structures, it linked fragmented patient records, offering a cohesive view of medical history, conditions, and care plans. This supported continuity of care and decision support. The model also showed potential for enabling cross-border research and queries by reducing semantic disparities. Conclusions Interoperability depends on the strategic use of standards. The CSSDM framework illustrates how combining varied standards can bridge data silos and build patient-centered knowledge graphs. This approach not only supports integrated care and research but also lays the groundwork for intelligent, scalable digital health ecosystems. Key messages • Combining diverse health data standards enables seamless interoperability, powering patient-centric knowledge graphs and advancing integrated care, research, and scalable digital health ecosystems. • CSSDM enables unified, patient-centric knowledge graphs by integrating diverse data across the care continuum.