Interoperability-Driven Digital Twins in Healthcare: A Conceptual and Technical Analysis of FHIR, openEHR, and OMOP

Digital Twins (DTs) are gaining attention as a promising approach for next-generation healthcare systems. However, their real-world adoption remains limited, mainly due to fragmented data environments and a lack of effective interoperability across clinical systems. Although much of the current research focuses on modeling and advanced analytics, the role of interoperability as a structural enabler has received less attention. This paper examines interoperability as a core requirement for healthcare DTs. It considers how three commonly used standards, HL7 FHIR, openEHR, and the OHDSI OMOP Common Data Model, support different needs across the DT lifecycle, including data exchange, semantic representation, and data reuse for analysis. Each of these standards is effective in specific contexts. OMOP, for instance, is widely used for cohort studies, openEHR supports structured longitudinal records, and FHIR is effective for system integration and data exchange. However, developing more complete DT solutions requires coordinating these complementary capabilities. The paper takes a lifecycle-and role-based view, suggesting that DTs are better understood as the result of coordinated data infrastructures rather than standalone systems. This lifecycle framework provides actionable guidance for scalable DT architectures.