R4 Ballot #2 (Mixed Normative/Trial use)

This page is part of the FHIR Specification (v3.5.0: R4 Ballot #2). The current version which supercedes this version is 5.0.0. For a full list of available versions, see the Directory of published versions . Page versions: R5 R4B R4 R3

8.22 Resource Linkage - Content

Patient Care

Work Group

Maturity Level: 0

Trial Use

Compartments: Practitioner

Identifies two or more records (resource instances) that are referring to the same real-world "occurrence".

8.22.1 Scope and Usage

This resource allows the assertion of linkages between multiple resource instances (generally of the same type) that are referring to the same underlying business objects. For example, multiple Condition records that refer to the same underlying problem/issue for a Patient; multiple AllergyIntolerance records that refer to the same reaction susceptibility; multiple Patient, Practitioner and/or RelatedPerson records that refer to the same human being or animal.

FHIR supports a process for sharing electronic records. It is common for multiple records to exist that deal with the same real-world phenomenon. This can result from information being captured by different systems, information being captured within a single system by different users (either deliberately to represent distinct perspectives or accidentally when a new record is created rather than updating an existing record). These multiple records may be referred to as "duplicate" records, but in practice they aren't often actually "duplicate" in that the data represented (and the history of the records) will be at least somewhat distinct.

In some cases, the solution upon identifying duplicates is to deprecate one of the records (e.g. by changing the status to "entered in error") and move all relevant information to the surviving record. In other cases, the resource may support the ability to establish a linkage directly between the resources. However, in some cases, both records may need to survive or there's a desire to have both resources continue to be maintained, perhaps because the resources live on different servers or have different 'owners'. The Linkage resource is intended to satisfy this use-case.

8.22.2 Boundaries and Relationships

The Person resource should be used to link a person independent of a specific health-related context. Linkage can be used for all other use cases.

Structure

Name	Flags	Card.	Type	Description & Constraints
Linkage	Σ I TU		DomainResource	Links records for 'same' item + Rule: Must have at least two items Elements defined in Ancestors: id, meta, implicitRules, language, text, contained, extension, modifierExtension
active	Σ	0..1	boolean	Whether this linkage assertion is active or not
author	Σ	0..1	Reference(Practitioner \| Organization)	Who is responsible for linkages
item	Σ I	1..*	BackboneElement	Item to be linked
type	Σ	1..1	code	source \| alternate \| historical LinkageType (Required)
resource	Σ	1..1	Reference(Any)	Resource being linked
Documentation for this format

UML Diagram (Legend)

XML Template

<Linkage xmlns="http://hl7.org/fhir"> 
 <!-- from Resource: id, meta, implicitRules, and language -->
 <!-- from DomainResource: text, contained, extension, and modifierExtension -->
 <active value="[boolean]"/><!-- 0..1 Whether this linkage assertion is active or not -->
 <author><!-- 0..1 Reference(Practitioner|Organization) Who is responsible for linkages --></author>
 <item>  <!--  1..* Item to be linked -->
  <type value="[code]"/><!-- 1..1 source | alternate | historical -->
  <resource><!-- 1..1 Reference(Any) Resource being linked --></resource>
 </item>
</Linkage>

JSON Template

{
  "resourceType" : "Linkage",
  // from Resource: id, meta, implicitRules, and language
  // from DomainResource: text, contained, extension, and modifierExtension
  "active" : <boolean>, // Whether this linkage assertion is active or not
  "author" : { Reference(Practitioner|Organization) }, // Who is responsible for linkages
  "item" : [{ // C? R!  Item to be linked
    "type" : "<code>", // R!  source | alternate | historical
    "resource" : { Reference(Any) } // R!  Resource being linked
  }]
}

Turtle Template

@prefix fhir: <http://hl7.org/fhir/> .


[ a fhir:Linkage;
  fhir:nodeRole fhir:treeRoot; # if this is the parser root

  # from Resource: .id, .meta, .implicitRules, and .language
  # from DomainResource: .text, .contained, .extension, and .modifierExtension
  fhir:Linkage.active [ boolean ]; # 0..1 Whether this linkage assertion is active or not
  fhir:Linkage.author [ Reference(Practitioner|Organization) ]; # 0..1 Who is responsible for linkages
  fhir:Linkage.item [ # 1..* Item to be linked
    fhir:Linkage.item.type [ code ]; # 1..1 source | alternate | historical
    fhir:Linkage.item.resource [ Reference(Any) ]; # 1..1 Resource being linked
  ], ...;
]

Changes since R3

Linkage

Linkage.active

Default Value "true" removed

Linkage.item.resource

Type changed from Reference to Reference(Resource)

See the Full Difference for further information

This analysis is available as XML or JSON.

See R3 <--> R4 Conversion Maps (status = 1 test that all execute ok. 1 fail round-trip testing and 1 r3 resources are invalid (0 errors).)

Structure

Name	Flags	Card.	Type	Description & Constraints
Linkage	Σ I TU		DomainResource	Links records for 'same' item + Rule: Must have at least two items Elements defined in Ancestors: id, meta, implicitRules, language, text, contained, extension, modifierExtension
active	Σ	0..1	boolean	Whether this linkage assertion is active or not
author	Σ	0..1	Reference(Practitioner \| Organization)	Who is responsible for linkages
item	Σ I	1..*	BackboneElement	Item to be linked
type	Σ	1..1	code	source \| alternate \| historical LinkageType (Required)
resource	Σ	1..1	Reference(Any)	Resource being linked
Documentation for this format

UML Diagram (Legend)

XML Template

<Linkage xmlns="http://hl7.org/fhir"> 
 <!-- from Resource: id, meta, implicitRules, and language -->
 <!-- from DomainResource: text, contained, extension, and modifierExtension -->
 <active value="[boolean]"/><!-- 0..1 Whether this linkage assertion is active or not -->
 <author><!-- 0..1 Reference(Practitioner|Organization) Who is responsible for linkages --></author>
 <item>  <!--  1..* Item to be linked -->
  <type value="[code]"/><!-- 1..1 source | alternate | historical -->
  <resource><!-- 1..1 Reference(Any) Resource being linked --></resource>
 </item>
</Linkage>

JSON Template

{
  "resourceType" : "Linkage",
  // from Resource: id, meta, implicitRules, and language
  // from DomainResource: text, contained, extension, and modifierExtension
  "active" : <boolean>, // Whether this linkage assertion is active or not
  "author" : { Reference(Practitioner|Organization) }, // Who is responsible for linkages
  "item" : [{ // C? R!  Item to be linked
    "type" : "<code>", // R!  source | alternate | historical
    "resource" : { Reference(Any) } // R!  Resource being linked
  }]
}

Turtle Template

@prefix fhir: <http://hl7.org/fhir/> .


[ a fhir:Linkage;
  fhir:nodeRole fhir:treeRoot; # if this is the parser root

  # from Resource: .id, .meta, .implicitRules, and .language
  # from DomainResource: .text, .contained, .extension, and .modifierExtension
  fhir:Linkage.active [ boolean ]; # 0..1 Whether this linkage assertion is active or not
  fhir:Linkage.author [ Reference(Practitioner|Organization) ]; # 0..1 Who is responsible for linkages
  fhir:Linkage.item [ # 1..* Item to be linked
    fhir:Linkage.item.type [ code ]; # 1..1 source | alternate | historical
    fhir:Linkage.item.resource [ Reference(Any) ]; # 1..1 Resource being linked
  ], ...;
]

Changes since Release 3

Linkage

Linkage.active

Default Value "true" removed

Linkage.item.resource

Type changed from Reference to Reference(Resource)

See the Full Difference for further information

This analysis is available as XML or JSON.

See R3 <--> R4 Conversion Maps (status = 1 test that all execute ok. 1 fail round-trip testing and 1 r3 resources are invalid (0 errors).)

See the Profiles & Extensions and the alternate definitions: Master Definition XML + JSON, XML Schema/Schematron + JSON Schema, ShEx (for Turtle) + see the extensions & the dependency analysis

8.22.3.1 Terminology Bindings

Path	Definition	Type	Reference
Linkage.item.type	Used to distinguish different roles a resource can play within a set of linked resources.	Required	LinkageType

Path

Definition

Type

Reference

Linkage.item.type

Used to distinguish different roles a resource can play within a set of linked resources.

Required

LinkageType

8.22.3.2 Constraints

id

Level

Location

Description

Expression

lnk-1

Rule

(base)

Must have at least two items

item.count()>1

8.22.4 Search Parameters

Search parameters for this resource. The common parameters also apply. See Searching for more information about searching in REST, messaging, and services.

Name	Type	Description	Expression	In Common
author	reference	Author of the Linkage	Linkage.author (Practitioner, Organization)
item	reference	Matches on any item in the Linkage	Linkage.item.resource (Any)
source	reference	Matches on any item in the Linkage with a type of 'source'	Linkage.item.resource (Any)