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Query Response to get DocumentUsing FHIR Messaging

Presented byPrashant Trivedi (HSCIC)

Background

• Alternates such as ADT A19 are unreliable• HL7 V3 query and response is complex• Supports a shift from “push” to “pull” styles

of architecture• Need for robust way of providing a Query

Response mechanism for the NHS in England

FHIR Messaging

• Uses an Atom Feed (aka Bundles) as a wrapper around the payloads

• Uses standard FHIR resources as entries within the Atom Feed

• Uses the ITK distribution envelope and web services as the transport mechanism

Query Response Interaction

FHIR Messages

• Get Document query message• Get Document query response message • Error message (Operation Outcome)

Message Structure

Get Document

Error Message

Get Document Response

FHIR Resources

• Message Header - This FHIR resource contain details about the type of message which is triggered by the system.

• Document Reference - This resource is used to describe the document which is being queried for. This resource will carry a link to the binary object which contains the actual document in binary format.

• Query - The query resource represents the query and response operation as single resource. The instance shall contain query parameters for which the response was generated by query fulfiller system. The same resource is used to carry a response class which has a reference to the Document Reference.

• Operation Outcome - This resource provides an error, warning or information message as result of the query and response interaction between two systems.

• Binary - This resource contains the base 64 encoded document itself.

Constraints

• Atom Feed <category> will be used to carry the ITK interaction names

• An ITK distribution envelope will be used to wrap the FHIR Atom Feed (Bundle)

• The Resource are constrained (profiled) for the query response get document use case (e.g. enterer, author, reason are restricted [0..0] in message header).

Why FHIR for Query Response

• All queries will be dealt in the same way.• The parameters for Query Resource will be published

separately• Individual resources can be validated against a profile

(coming soon)• Easier implementation as FHIR and the Open Source

community provides tools for both implementers and specification development

Thank you