Notice
- Important: This guidance is under active development by NHS England and content may be added or updated on a regular basis.
- This Implementation Guide is currently in Draft and SHOULD NOT be used for development or active implementation without express direction from the NHS England Genomics Unit.
Composition document
As a consequence of supporting RESTful update operations on resources within the central broker, some information, such as patient history may change over time. This poses a problem when interrogating past 'documents', or resources such as ServiceRequests or DiagnosticReports, as the information contained within them, or the references to other resources, may change after a test request has been closed.
To maintain the accuracy of historic information, such as the observations a genomic report was based on, it may be necessary to create an immutable snapshot of the resources related to a ServiceRequest or DiagnosticReport after closure of a request.
To support this, the central broker can create Document Bundles using the $document operation on Composition. The Compositions would need to be generated on closure of a ServiceRequest (e.g. a ServiceRequest being marked as 'completed' or 'revoked', or a DiagnosticReport marked as 'final', 'amended', 'corrected' or 'appended') to capture the final IDs for the ServiceRequest and DiagnosticReport.
Upon generation of the Composition, the central broker can call the $document operation on the Composition resource, using the appropriate GraphDefinitions to follow the required resource references and generate a Bundle of type 'document' containing all the resources forming the order or result:
GET [base]/Composition/[id]/$document?persist=true&graph=genomics-test-result
This Bundle could then be stored/accessible via the Bundle endpoint as an immutable snapshot of the order/result at that point in time, regardless of whether any changes were made to those resources after generation:
GET [base]/Bundle/[id]
or searched via:
GET [base]/Bundle?composition.entry:DiagnosticReport=[id]
GET [base]/Bundle?composition.entry:ServiceRequest=[id]
The sequence diagram for the proposed process is given below:
