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Sender and Receiver Requirements Overview

Overview of sender and receiver requirements for ITK3 payloads.

These sections describe the sender and receiver requirements for ITK3 FHIR payloads.

For the purpose of this specification:

  • An ITK3 FHIR Document payload is defined as below:

FHIR Resources can be used to build documents that represent a Composition: a set of coherent information that is a statement of healthcare information, particularly including clinical observations and services. A document is an immutable set of Resources with a fixed presentation that is authored and/or attested by humans, organizations and devices.

All documents have the same structure: A Bundle of Resources of type “document” that has a Composition Resource as the first Resource in the bundle, followed by a series of other Resources, referenced from the Composition Resource that provide supporting evidence for the document. The Bundle gathers all the content of the document into a single XML document which may be managed as required. The Resources include both human readable and computer processable portions.

There are two key identifiers on the document:

  • The Document identifier (mandatory). This is found in and is unique for this instance of the document, and is never re-used.
  • The Composition identifier (mandatory). This is found in Composition.identifier, and is the same for all documents that are derived from this Composition.

The document has two dates in it:

  • The Document date (mandatory). This is found in Bundle.meta.lastUpdated and identifies when the document bundle was assembled from the underlying Resources.
  • The Composition date (mandatory). This is found in, which is when the author wrote the document.

Once assembled into a bundle, the document is immutable - its content can never be changed, and the document id can never be reused. Any additional documents derived from the same Composition SHALL have a different document id.

Tags: fhir

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