Interoperability and Health Information Exchange
Exchange models
Interoperability levels: syntactic (format), semantic (shared meaning), and organizational (workflow and policy). Know the exchange patterns: push (directed send), pull/query (e.g., a query for records), and publish/subscribe. Familiarize yourself with HL7 v2 messaging, HL7 FHIR resources and RESTful APIs, CDA documents, and the role of IHE profiles and national networks.
Concepts to master
- HL7 v2 segments and fields vs. FHIR resources, references, and bundles.
- Terminology binding in FHIR (required, extensible, preferred) and what each means for validation.
- Patient identity and matching: MPI, probabilistic vs. deterministic matching, and the risk of overlays and duplicates.
- Consent and information blocking; TEFCA-style exchange governance concepts.
- Interface engines, mapping, and the difference between an interface and an integration.
- ADT feeds and their role in triggering downstream workflows.
Traps
Questions may ask which standard to use for a real-time query and expect FHIR, while batch document exchange points to CDA. Another trap: assuming patient matching is exact; identity resolution is probabilistic and error-prone. Also watch for conflating semantic interoperability with simply moving messages-receiving a message does not mean the receiver understands the codes.
Rule of thumb
Ask what is being exchanged: a message (event), a document (persisted snapshot), or a resource (queryable data). The answer usually determines the standard.
Worked example
A hospital sends an ADT notification to a community provider: HL7 v2 ADT (or a FHIR notification) carries the event, but semantic interoperability requires that diagnoses and medications be coded with shared terminologies, not free text.