Advanced and secure architectural EHR approaches.

OBJECTIVES

Electronic Health Records (EHRs) provided as a lifelong patient record advance towards core applications of distributed and co-operating health information systems and health networks. For meeting the challenge of scalable, flexible, portable, secure EHR systems, the underlying EHR architecture must be based on the component paradigm and model driven, separating platform-independent and platform-specific models.

METHODS

Allowing manageable models, real systems must be decomposed and simplified. The resulting modelling approach has to follow the ISO Reference Model - Open Distributing Processing (RM-ODP). The ISO RM-ODP describes any system component from different perspectives. Platform-independent perspectives contain the enterprise view (business process, policies, scenarios, use cases), the information view (classes and associations) and the computational view (composition and decomposition), whereas platform-specific perspectives concern the engineering view (physical distribution and realisation) and the technology view (implementation details from protocols up to education and training) on system components. Those views have to be established for components reflecting aspects of all domains involved in healthcare environments including administrative, legal, medical, technical, etc. Thus, security-related component models reflecting all view mentioned have to be established for enabling both application and communication security services as integral part of the system's architecture. Beside decomposition and simplification of system regarding the different viewpoint on their components, different levels of systems' granularity can be defined hiding internals or focusing on properties of basic components to form a more complex structure. The resulting models describe both structure and behaviour of component-based systems.

RESULTS

The described approach has been deployed in different projects defining EHR systems and their underlying architectural principles. In that context, the Australian GEHR project, the openEHR initiative, the revision of CEN ENV 13606 "Electronic Health Record communication", all based on Archetypes, but also the HL7 version 3 activities are discussed in some detail. The latter include the HL7 RIM, the HL7 Development Framework, the HL7's clinical document architecture (CDA) as well as the set of models from use cases, activity diagrams, sequence diagrams up to Domain Information Models (DMIMs) and their building blocks Common Message Element Types (CMET) Constraining Models to their underlying concepts.

CONCLUSION

The future-proof EHR architecture as open, user-centric, user-friendly, flexible, scalable, portable core application in health information systems and health networks has to follow advanced architectural paradigms.