Written by Technical Team | Last updated 15.11.2025 | 9 minute read
MEDITECH Expanse has become a strategic platform for healthcare organisations seeking a modern, web-based EPR/EHR capable of integrating seamlessly with a broad ecosystem of legacy and next-generation digital health solutions. As hospitals modernise their technology stack, the demand for reliable interoperability grows rapidly — not only because systems need to share data, but because clinicians increasingly rely on real-time, accurate information to deliver safe and coordinated care.
At the centre of this interoperability challenge are two major standards: HL7 v2.x and HL7 FHIR. MEDITECH Expanse supports both extensively, enabling everything from traditional MLLP-based message feeds to dynamic API-driven integrations through FHIR and SMART on FHIR frameworks. However, simply turning on HL7 messaging or pointing a FHIR app at Expanse APIs rarely produces sustainable, high-quality results. The real power emerges when organisations invest in optimising the entire workflow — how data moves, is validated, transformed, enriched, monitored and surfaced within clinical workflows.
This article explores how to design, implement and refine HL7 and FHIR workflows specifically for MEDITECH Expanse. It covers architectural patterns, mapping and normalisation strategies, testing and observability, and the governance practices necessary to ensure long-term reliability, scalability and clinical safety.
Most MEDITECH Expanse environments operate within a hybrid interoperability model. HL7 v2 remains deeply embedded in hospital operations, supporting ADT, orders, results and other high-volume transactional workflows. These HL7 v2 interfaces are widely used by PAS, LIS, RIS, pharmacy systems and numerous operational platforms, and they remain the fastest way to exchange structured, event-driven information.
In parallel, FHIR introduces a modern, flexible API layer designed for richer, app-focused data exchange. MEDITECH Expanse exposes a growing suite of FHIR R4 endpoints, including core resources such as Patient, Observation, Encounter, AllergyIntolerance and Medication. When combined with SMART on FHIR, Expanse becomes capable of launching third-party applications directly within clinical workflows using secure, standards-based authorisation.
This dual model — HL7 v2 for messaging and FHIR for APIs — means organisations should avoid viewing interoperability as an either-or decision. Instead, it is about selecting the right standard for the right purpose. HL7 v2 is ideal for high-throughput, predictable event-based exchanges. FHIR is best suited for data retrieval, decision support tools, analytics platforms, patient-facing apps and mobile solutions that need rapid, structured access to live clinical data.
On top of these, MEDITECH’s broader interoperability toolkit includes the Greenfield Workspace for developer testing and the Traverse suite for health information exchange and targeted retrieval workflows. In regional ecosystems or enterprise environments, Traverse and FHIR often complement each other, enabling shared care records, remote monitoring platforms, and cross-organisational clinical collaboration.
Understanding how these components work together is one of the first steps toward building robust integration workflows. It allows integration teams to strategically assign responsibilities: HL7 v2 for guaranteed message delivery, FHIR for query-based data access, and internal APIs or repositories for analytics and reporting.
While many hospitals begin with simple point-to-point integrations — for example, Expanse connecting directly to a lab system — this approach quickly becomes unsustainable as the environment grows. Point-to-point connections multiply complexity, making maintenance difficult and introducing high risk whenever changes are deployed.
A scalable architecture typically employs an integration engine or interoperability platform between Expanse and the rest of the ecosystem. This middleware handles routing, transformation, monitoring and orchestration for HL7 v2, FHIR and other protocols. It consolidates logic that would otherwise be duplicated across many systems and gives technical teams a single place to manage interfaces.
A well-designed integration architecture for Expanse often includes:
By treating Expanse as one major system among many — rather than the centre of the integration universe — organisations can design workflows with greater flexibility. Integration logic becomes system-agnostic, and Expanse plugs into the architecture through well-defined interfaces, making future system replacements or workflow changes far easier.
Performance considerations are also essential. HL7 v2 messages can surge during busy clinical periods such as morning rounds or mass ADT updates. Simultaneously, FHIR-driven apps may generate large numbers of API calls for panels, dashboards or mobile tools. To support this, integration platforms should employ:
Finally, it is critical to distinguish between real-time interoperability and analytical data needs. MEDITECH’s Data Repository (DR) and other analytical platforms provide powerful support for reporting and BI, but they cannot replace HL7 or FHIR for transactional workflows. Keeping these domains separate — even if they share a common data transformation pipeline — ensures that clinical data is both timely and reliable.
Mapping is where the theory of interoperability meets the reality of clinical workflows. High-quality mapping ensures that information retains its meaning as it crosses system boundaries, and for MEDITECH Expanse, this can require careful interpretation of both HL7 v2 and FHIR conventions.
HL7 v2 data from Expanse frequently includes organisation-specific customisations, such as local codes, unique segment usage, or altered repeating field behaviours. Even within standard message types like ADT or ORM, facilities may configure Expanse to emit slightly different sets of segments or trigger messages at different workflow steps. Normalisation — ensuring that all inbound and outbound data is reshaped into a consistent structure — helps maintain clarity across the ecosystem.
FHIR introduces similar challenges. Although Expanse adheres to established FHIR R4 profiles, every implementation interprets certain elements differently. Extensions, terminology bindings, optional fields and search behaviours can vary across applications. When integrating with national or regional standards, or when consuming FHIR from multiple vendors, mapping between profiles becomes an essential task.
The most effective way to reduce complexity is to rely on a canonical data model. Rather than building bespoke mappings for every pair of systems, teams map each system into a shared organisational model, and then from that model to any target system. This reduces redundancy, simplifies maintenance and dramatically improves long-term scalability.
Mapping must also align with real clinical workflows. Expanse triggers particular HL7 events at defined points in the patient journey — for example, at registration, admission, transfer between wards, discharge or encounter updates. If downstream systems misinterpret when or why these events occur, discrepancies will appear in bed management systems, patient tracking tools or external clinical platforms.
FHIR adds new opportunities for workflow optimisation. Rather than pushing data through traditional messaging, FHIR introduces resources such as Task, ServiceRequest and CarePlan that support more interactive and semantic clinical processes. Carefully applied, these can support advanced workflows including:
However, these capabilities should be deployed where they add genuine value and not simply because the standard supports them. Thoughtful alignment with clinical priorities ensures that FHIR adoption enhances usability rather than complicating existing processes.
A final, crucial component of mapping is terminology management. To maintain accurate clinical meaning, organisations must align code sets across systems — including SNOMED CT, LOINC, ICD, OPCS and custom local code lists. Integrating Expanse into a broader terminology strategy ensures that coded data is consistent, enabling better analytics, decision support and clinical safety across the organisation.
No matter how well an interface is designed, it will only operate reliably if it is rigorously tested and continuously monitored. MEDITECH Expanse supports structured testing through tools such as the Greenfield Workspace, allowing developers to exercise FHIR endpoints against a safe, realistic environment. HL7 v2 messages can also be validated within Expanse’s test instances or replayed through interface engines to simulate real-world workflows.
A robust testing strategy combines both technical validation and clinical safety assurance. Technical testing verifies that message formats are valid, FHIR resources conform to expected profiles, identifiers are correctly populated, and endpoints handle both expected and error conditions gracefully. Clinical validation ensures that data lands in the right place and is visible in Expanse and downstream systems in ways that align with clinician expectations.
Effective monitoring infrastructure can dramatically reduce risk and operational downtime. This often includes:
Security and audit trails should also be considered a core component of monitoring. HL7 engines must log connection attempts, configuration changes and message failures. FHIR endpoints should capture authentication events, token usage and resource access patterns. This not only supports incident investigation but also helps maintain compliance with regulatory frameworks and information governance standards.
Troubleshooting workflows benefit enormously from having structured runbooks, standardised policies for error handling and diagnostic tools. For example, replay mechanisms allow problematic HL7 messages to be reprocessed safely, while correlation IDs allow teams to track a patient record across several systems. Over time, integration teams should harvest insights from recurring issues to strengthen validation logic, improve training for system teams, or adjust mapping rules to reduce ambiguity.
As interoperability becomes more complex — with additional systems, mobile apps, analytical platforms and regional data-sharing requirements — strong governance becomes essential. Successful organisations establish clear oversight structures, often governed by cross-functional boards that include clinical, operational, technical and information governance representatives.
These groups help prioritise integration initiatives, approve new interface requirements, standardise architectural patterns and ensure that all systems align with broader organisational strategy. Without such governance, integration efforts can become fragmented, inconsistent or insecure.
Security must be integrated into every stage of HL7 and FHIR workflow design. For HL7 v2, this includes secure transport (typically using TLS), strong authentication for interface engine access, encrypted storage for logs and message archives, and least-privilege principles for user accounts. For FHIR, robust API gateway policies are essential — including rate limiting, IP restrictions, OAuth2 and OpenID Connect flows, and comprehensive secrets management.
Because MEDITECH Expanse supports SMART on FHIR, organisations must also govern application registration and clinical workflow launch permissions carefully. Clear policies ensure that only trusted, vetted applications can run contextually within Expanse or access patient data.
Future-proofing Expanse integrations means building adaptability into the system. Standards will evolve, Expanse modules will update, workflows will shift, and new digital health technologies will emerge. Patterns such as canonical modelling, message brokering, reusable transformation frameworks and strong documentation allow organisations to adapt without major rework.
Just as importantly, future-proofing is cultural. Integration success depends on teams who understand both technology and clinical workflow. Investing in staff who can bridge those worlds — analysts who understand Expanse configuration, architects who understand HL7 and FHIR deeply, and clinicians who can articulate workflow requirements — ensures that the organisation remains ready for ongoing change and innovation.
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