2nd DSTU Draft For Comment

This page is part of the FHIR Specification (v0.4.0: DSTU 2 Draft). The current version which supercedes this version is 5.0.0. For a full list of available versions, see the Directory of published versions . Page versions: R5 R4B R4 R3 R2

1.12 Appendix: HL7 EHR Functional Model and FHIR

The HL7 EHR System Functional Model provides a reference list of functions that may be present in an Electronic Health Record System. While FHIR is an implementation focused on exchange of information in healthcare, this often happens in the context of an EHR. This table briefly describes one way that FHIR can be used to meet the requirements described in the EHR-FM and is provided to help readers of the FHIR specification understand how FHIR can be used. There are many other equally valid ways to implement the EHR-FM and to make use of FHIR.

EHR FunctionFHIR Implementation Notes
IN.1SecurityFHIR defines parts of the security infrastructure, and delegates others to standard web based security frameworks
IN.1.1Entity AuthenticationFHIR assumes that the users are authenticated. OAuth is the preferred mechanism
IN.1.2Entity AuthorizationFHIR does not currently provide any resources to describe or manage access-control permissions. By default, underlying web frameworks such as SAML would be used. See the security section for a discussion of binding between FHIR and SAML
IN.1.3Entity Access ControlSee above about SAML / OAuth
IN.1.4Patient Access ManagementSee Security Labels
IN.1.5Non-RepudiationThe provenance resource tracks the timestamps, actors, digital signatures associated with resources
IN.1.6Secure Data ExchangeTLS (https:) should be used for all production exchange of data. All conformant FHIR RESTful implementations SHALL be able to use https
IN.1.7Secure Data RoutingFHIR allows for brokers and various forms of messaging that support assured destinations and delivery (also see IN.2.2 below)
IN.1.8Information AttestationSee the provenance resource
IN.1.9Patient Privacy and ConfidentialityFHIR does not include functionality related to this requirement, though implementations would be expected to provide this
IN.2Health Record Information and ManagementThis is a core application of the FHIR capabilities
IN.2.1Data Retention, Availability and DestructionA FHIR RESTful server gives precise and fine-grained control of retention, availability and destruction of resources, all clearly described by the conformance statement
IN.2.2Auditable RecordsFHIR provides the SecurityEvent resource for auditable records.
IN.2.3SynchronizationFHIR supports synchronization using standard web publication/subscription methods via Bundles (i.e. Atom feeds). Atom-based pub/sub may be push or pull based, and can include all resources of a particular type, or selected subsets of the resources. In addition, groups of resources can be exchanged in bundles, keeping a set of related resources in synchronization
IN.2.4Extraction of Health Record InformationFHIR does not provide report formats, but does provide extensive search and retrieval functions to assist with building such reports
IN.2.5Store and Manage Health Record InformationA FHIR RESTful server can store and manage health information persistently - see below for further information.
IN.2.5.1/2Manage Structured and Unstructured Health Record InformationThe dual contents of FHIR resources - structured data and XHTML narrative - provide seamless support for dealing with a mix of structured and unstructured information
IN.3Registry and Directory ServicesThe FHIR Administration resources provide a registry based access to patients, providers, etc.
IN.4Standard Terminologies and Terminology ServicesFHIR encourages the use of standard terminologies wherever possible, and provides full support for their use through a variety of terminology related data types. FHIR does not define a terminology infrastructure or service, but does define the Profile and ValueSet resources to describe how terminology is used in a FHIR context
IN.5Standards-based InteroperabilityFHIR is a definition of a standard on which to base interoperability
IN.5.1Interchange StandardsThis is the core focus of FHIR. See below for discussion of interaction modes
IN.5.2Interchange Standards Versioning and Maintenance FHIR version maintenance is described here
IN.5.3Standards-based Application IntegrationFHIR enables simple integration through use of an easy to understand, use and debug web-based infrastructure. The same framework used within an EHR for persistence can also offer a simple way to implement exchange
IN.5.4Interchange AgreementsThe FHIR Conformance Statement and Resource Profile resources provide a registry based infrastructure for individual trading partner agreements, as well as for community based ones
IN.6Business Rules ManagementFHIR does not address this requirement at this point in time
IN.7Workflow ManagementFHIR does not address this requirement at this point in time, though the resources and services exist to support this functionality

The EHR functional model describes several modes for interaction between systems. Each of these can be implemented in several different ways using FHIR

Interaction ModesFHIR Options
Unsolicited Notifications
e.g. a patient has arrived for a clinic appointment
  • create/update new resource via http
  • push resources using atom
  • Send FHIR Message (if appropriate event is defined)
Query/Response
e.g., Is Adam Everyman known to the system? Yes, MRN is 12345678.
  • search with parameters
  • A query message (though not defined yet)
Service Request and Response
e.g., Laboratory Order for Fasting Blood Sugar and a response containing the results of the test. 		Could be supported either through Messaging or SOA solutions. Request/Response support is not yet defined
Information Interchange between organizations (e.g. in a RHIO, or in a National Health System)
  • pub/sub using atom (push or pull)
  • RESTful interface
  • FHIR messaging
Structured / Unstructured clinical document, e.g., dictated surgical note See the Documents

The combination of a properly secured and managed FHIR server, along with enforced use of the SecurityEvent and Provenance resources ensures that the core record management functions defined in the EHR-FM are met:

  • Lifespan/Lifecycle tracking, including capturing source, origination and authorship information, along with tracking of views and exchanges
  • Attestation for accuracy and completeness, along with digital signature
  • A full version history with content retention
  • Retention and persistence

Additional functionality, not defined at this point in time in FHIR, is required to ensure non-repudiation, access control, and consent tracking.