Non-patient File Sharing (NPFS), published by IHE IT Infrastructure Technical Committee. This guide is not an authorized publication; it is the continuous build for version 2.2.1-current built by the FHIR (HL7® FHIR® Standard) CI Build. This version is based on the current content of https://github.com/IHE/ITI.NPFS/ and changes regularly. See the Directory of published versions

2:3.88 Search File [ITI-88]

2:3.88.1 Scope

The transaction is used by the File Consumer to find DocumentReference Resources that are stored and managed by a File Manager. The DocumentReference Resources represent files that are not associated with patient.

2:3.88.2 Actor Roles

Table 2:3.88.2-1: Actor Roles

Actor:	File Consumer
Role:	Searches for a list of DocumentReference Resources based on a set of search parameters
Actor:	File Manager
Role:	Returns a list of DocumentReference Resources that match the search parameters provided

2:3.88.3 Referenced Standards

HL7 FHIR

HL7 FHIR Release 4.0

2:3.88.4 Messages

2:3.88.4.1 Search File Request Message

This message is a parametrized HTTP GET that allows a File Consumer to search for a list of the FHIR DocumentReference Resources managed by the File Manager, based on a set of search parameters.

2:3.88.4.1.1 Trigger Events

A File Consumer sends this message to the File Manager when it needs to discover DocumentReference Resources for non-patient-related files.

2:3.88.4.1.2 Message Semantics

The File Consumer executes an HTTP GET against the File Manager. This request shall comply with requirements specified in the HL7^® FHIR^® standard http://hl7.org/fhir/R4/http.html#search.

The search target URL follows the FHIR HTTP specification, addressing the DocumentReference Resource http://hl7.org/fhir/R4/http.html:

[base]/DocumentReference?[Parameters]

The Parameters element represents a series of encoded name-value pairs representing the filter for the query, as specified in Section 3.88.4.1.2.1, as well as control parameters to modify the behavior of the File Manager such as response format, or pagination.

2:3.88.4.1.2.1 Query Search Parameters

The File Consumer may supply and the File Manager shall support all the query parameters listed below:

• identifier

This parameter, of type token, allows the File Consumer to search on the logical identifier of the resource.

• _id

  This parameter, of type token, allows the File Consumer to search on the logical id assigned to the resource.

• patient

This parameter shall always be used in this transaction to find resources that do not have the patient element valued. To achieve that, this parameter shall be used with the exists modifier (e.g., patient:exists=false).

The File Consumer shall not use the query parameter subject with a reference to a Patient Resource.

• date

This parameter, of type date, specifies the time when the file, to which the DocumentReference refers, was submitted. The File Consumer shall use the date and interval mechanism described in HL7 FHIR (http://hl7.org/fhir/R4/search.html#date) to indicate a specific date, or a date that lies within the range specified by the parameter.

• author.identifier

This parameter, of type token, specifies the identifier of the author that has submitted the file. See ITI TF-2: Appendix Z.2.2 (currently in the Appendix Z on HL7 FHIR Trial Implementation Supplement) for use of the token data type.

• format

This parameter, of type token, specifies the file’s format.

• language

This parameter, of type token, specifies the language of the file.

• location

This parameter, of type uri, specifies the URI where the file can be found.

• status

This parameter, of type token, specifies the status of the file.

• relatesto

This parameter, of type reference, specifies one or more existing DocumentReference Resources that have been replaced by the submitted DocumentReference Resource.

• relation

This parameter, of type token, specifies the type of relation that the file being searched has with the targeted file specified in the relatesTo parameter, see http://hl7.org/fhir/R4/valueset-document-relationship-type.html for the type of relation allowed.

• relationship

This parameter, of type composite, is the combination of the relatesTo and relation search parameter.

2:3.88.4.1.2.2 Populating Expected Response Format

See ITI TF-2: Appendix Z.6 (currently in the Appendix Z on HL7 FHIR Trial Implementation Supplement) for details.

2:3.88.4.1.3 Expected Actions

The File Manager shall process the query to discover DocumentReference Resources that are not associated to any patient and that match the search parameters. The File Manager shall send a Search File Response message containing matching results.

The File Manager may return DocumentReference Resources that are not constrained as specified in Resource Profile: NPFS DocumentReference.

2:3.88.4.2 Search File Response Message

The File Manager returns a HTTP Status code appropriate to the processing as well as a list of the matching DocumentReference Resources.

2:3.88.4.2.1 Trigger Events

The File Manager has completed the processing of the Search File Request message.

2:3.88.4.2.2 Message Semantics

Based on the query results, the File Manager shall either return an error or success.

Guidance on handling Access Denied related to use of 200, 403 and 404 can be found in ITI TF- 2: Appendix Z.7 (currently in the Appendix Z on HL7 FHIR Trial Implementation Supplement).

When the File Manager needs to report an error, it shall use HTTP error response codes and should include a FHIR OperationOutcome with more details on the failure. See FHIR http://hl7.org/fhir/R4/http.html and http://hl7.org/fhir/R4/operationoutcome.html.

If the Search File Request message is processed successfully, whether or not any matching DocumentReference Resources are found, the HTTP status code shall be 200. The Search File Response message shall be a Bundle Resource containing zero or more DocumentReference Resources. If the File Manager is responding with warnings, the Bundle Resource shall also contain an OperationOutcome Resource that contains those warnings.

The response shall adhere to the FHIR Bundle constraints specified in ITI TF-2: Appendix Z.1 (currently in the Appendix Z on HL7 FHIR Trial Implementation Supplement).

2:3.88.4.2.3 Expected Actions

The File Consumer shall process the results according to application-defined rules.

If a File Consumer cannot automatically recover from an error condition, it should, at a minimum, display the error to the user.

2:3.88.4.3 CapabilityStatement Resource

File Managers implementing this transaction shall provide a CapabilityStatement Resource as described in ITI TF-2: Appendix Z.3 indicating the transaction has been implemented.

• Requirements CapabilityStatement for File Consumer
• Requirements CapabilityStatement for File Consumer implementing Retrieve File
• Requirements CapabilityStatement for File Manager

2:3.88.5 Security Considerations

See NPFS Security Considerations.

The files are not Patient specific, but they may have other needs for security controls, such as business knowledge restrictions. Thus the use of Security may be applicable. Actors involved in this transaction should be aware that even if the Resources exchanged do not contain PHI or other private information, exchange of those Resources could compromise patient care or have other legal ramifications. For general security considerations, see ITI TF-2: Appendix Z.8.

2:3.88.5.1 Security Audit Considerations

The File Consumer when grouped with ATNA Secure Node or Secure Application Actor shall be able to record a Search File Consumer Audit Event Log.

The File Manager when grouped with ATNA Secure Node or Secure Application Actor shall be able to record a Search File Manager Audit Event Log.