Health NZ | Te Whatu Ora FHIR Screening Implementation Guide, published by Health New Zealand | Te Whatu Ora. This guide is not an authorized publication; it is the continuous build for version 0.9.2 built by the FHIR (HL7® FHIR® Standard) CI Build. This version is based on the current content of https://github.com/tewhatuora/fhir-screening/ and changes regularly. See the Directory of published versions

Overview of screening summary searching

API consumers obtain screening summaries using the standard FHIR search API.

A search is done by a GET on the /DocumentReference REST resource, using FHIR's _include operation to incorporate the patient demographic data as a Patient FHIR instance.

For a description of the parameters API consumers can specify in a screening summary search see the API capability statement

In successful search scenario, the API returns a FHIR Bundle, with potentially two kinds of entry:

1. a mode:#match entry which is a profiled DocumentReference instance (containing the summary document rendition), and
2. a mode:#include entry which is a profiled Patient instance (containing subject demographic data).

If a screening summary document cannot be rendered for a given subject NHI (this happens when the specified subject has no screening history in the National Screening Register) the API will return an OperationOutcome as a mode:#outcome entry in a FHIR Bundle.

The following diagram shows these FHIR instances the API returns for a DocumentReference search.

The object diagram below illustrates the structure of FHIR DocumentReference instances returned by enquiries to this FHIR API.

---

Example search query

  GET {API_URL}/DocumentReference?
    subject:identifier={NHI number}
    & category=http://snomed.info/sct|1230046007
    & _include=DocumentReference:subject
    [& contenttype=application/pdf]

API consumers should use the following parameters to constrain every search for screening summaries.

request parameter	description
subject:identifier	Specifies the subject NHI number to search for.
category	Filters screening summaries by the type of national screening programme. Refer to [this ValueSet] (ValueSet-nz-screening-programmetype-code.html) for codes which are valid codes to use.
_include	Includes the subject patient demographic as a Patient instance (NzProfile from NZ Base IG) in the response.
contenttype (optional)	Specify the preferred content type of the rendered screening summary report. **By default the API returns the screening summary rendered as HTML (text/html). The API consumer may specify application/pdf to get a PDF rendition instead.

Search API response

The API returns a FHIR type:#searchset Bundle resource instance containing the results of the search.

For each entry in the response Bundle, up to three search mode types may appear as described below.

entry mode	Circumstances when returned	notes
match	In normal searches this entry provides the matching subject's screening summary document as a ScreeningSummaryDocument (DocumentReference) resource instance	Bundle.total counts match mode entries only.
include	In normal searches with the _include operation this entry provides the matching subject's data as an included NzPatient (Patient) resource instance	An include entry will only ever appear in association with a match entry, and not on its own
outcome	When the API needs to return extra information message(s) in a FHIR OperationOutcome resource instance	An outcome entry can be pressent whether or not there are any match entries.

Note: API consumers MUST check all entries in each result Bundles for searches they request.

No matching subject NHI

If the API finds no screening records for a specified NHI subject identifier, the API returns 200 OK HTTP code and a Bundle with no #match entries ("total":0).

This API SHALL NOT validate NHI identifiers given as a search parameters. Use the New Zealand NHI FHIR API for NHI matching and validation purposes.

Error scenarios

In the event of an authorization or technical error, this API returns an HTTP status code, and when a RESTful interaction has failed, error or warning messages in an OperationOutcome in the response payload (as per FHIR specification).

For details see Search Response Statuses in the API capability statement.