FHIR

FHIR (Fast Healthcare Interoperability Resources) is a standard for exchanging healthcare information, developed by HL7 International. It defines data formats and elements, called resources, and a programmable API for accessing them.

Core concepts: Resources such as Patient, Observation, Medication form modular building blocks that can be assembled into interoperable datasets. Data can be serialized in JSON or XML and accessed via a RESTful interface using standard operations (read, search, create, update, delete). Profiles and implementation guides tailor resources to specific contexts.

Architecture and standards: FHIR favors modern web technologies; it supports REST, OAuth 2.0, OpenID Connect, and can transport data using JSON, XML, or RDF. Its emphasis on modularity and lightweight implementation aids mobile and cloud-based use.

History and development: Initiated around 2011 to provide a flexible alternative to legacy HL7 messaging. Released as DSTU versions and later matured into R3 (and R4), with ongoing work toward R5. Governance is through HL7 International.

Adoption and use: Widely adopted by electronic health record vendors, health information exchanges, and health apps; used in U.S. interoperability initiatives and by programs such as SMART on FHIR, which enables app-based interactions with EHRs.

Security and conformance: Implementations commonly use OAuth 2.0 and OpenID Connect for authorization; TLS for transport security; conformance is supported by test suites and implementation guides, as well as profile registries.

Limitations and criticism: The flexibility of profiling can lead to interoperability gaps if profiles diverge; managing version changes and mappings can be complex for some organizations.