See Understanding the Group Resource for additional information. An example from the QUARTET USA trial will be described here and can be viewed at QUARTET_Eligibility_Criteria.

The inclusion and exclusion criteria in the Quartet USA Trial that need to be represented in FHIR are as follows:

Inclusion Criteria:

• Adults (≥18 years)
• Spanish or English speaker.
• Previous documentation within the past 24 months of hypertension or high blood pressure (SBP 130-179 mmHg or DBP 80-109 mmHg) from general practitioner, pharmacist or health care professional (e.g., medical assistant, physician or nurse).
• Either: 1) Untreated (automated) clinic SBP 140-179 or DBP 90-109 mmHg in the last 12 weeks, OR 2) Monotherapy with clinic SBP 130-159 or DBP 85-99 mmHg in the last 12 weeks.
• Either: 1) Treatment naïve, OR 2) Currently not on treatment (not take in last 4 weeks), OR 3) Currently taking 1 BP lowering drug (ACE, ARB, CCB, thiazide- or thiazide-like diuretic, BB, MRA, alpha blocker) at any dose.
• Research grade blood pressure measurement (baseline mean) SBP>= 115 mmHg and DBP >= 60 mmHg

Exclusion Criteria:

• Known contraindication to candesartan, amlodipine, indapamide or bisoprolol.
• Previous diagnosis of coronary artery disease, stroke, or heart failure.
• Presence of significant proteinuria (based on 3+ proteinuria via spot urinalysis or >300mg/dL of proteinuria based on random urinary albumin-to-creatinine ratio testing of 300 mg/g)
• Evidence of secondary cause of hypertension e.g., renal artery stenosis; significant renal impairment (eGFR <50 ml/min/1.73 m2), raised serum potassium (above lab normal limit of 5.5 mEq/L).
• Women who are pregnant, breast feeding or of childbearing potential and are not using and do not plan to continue using medically acceptable form of contraception throughout the study (pharmacological or barrier methods).
• Concomitant illness, physical impairment or mental condition which in the opinion of the study team / primary care physician could interfere with the conduct of the study including outcome assessments.
• Participation in a concurrent interventional medical investigation or pharmacologic clinical trial. Patients in observational, natural history or epidemiological studies not involving an intervention are eligible.
• Participant's responsible primary care or other responsible physician believes it is not appropriate for participant to switch current monotherapy.
• Inability or unwillingness to provide written informed consent.
• Unable to complete study procedures.

We will start by creating a FHIR Group Resource with a StudyEligibilityCriteria Profile. This instance of Group Resource is being used to define the criteria for group membership, therefore the membership element has a value of “definitional”. For a definitional Group, a type element is required, and the type element has a value of “person”.

There are 6 inclusion criteria and 10 exclusion criteria in this study.

The individual must meet all of these 16 criteria in order to be included in the study. Therefore the combinationMethod element will have a value of “all-of”.

The first criterion, Adults (≥18 years), can be fully represented as structured data and shows how a Group.characteristic element is used. The Group.characteristic element has 3 required elements: code, value[x], and exclude.

The code element uses a CodeableConcept datatype and represents the type of characteristic. In this first criterion, the type of characteristic is “Age” and a SNOMED-CT term is expressed as:

“code”: { "coding" : [ { "system" : "http://snomed.info/sct", "code" : "397669002", "display" : "Age" } ] }

The value[x] element could be expressed with a number of different datatypes: CodeableConcept, Quantity, and Range are commonly used for expression matching values of “Age”. In this example (18 years or older), the Quantity datatype is selected and the corresponding JSON is:

"valueQuantity" : { "value" : 18, "comparator" : ">=", "unit" : "years", "system" : "http://unitsofmeasure.org", "code" : "a" }

This code/value pairing (Age >= 18 years) is an inclusion criterion (not an exclusion criterion), so the exclude element will have a value of “false”.

Optionally, the Group.characteristic element can have a human-readable description, so we included a description element with a value of “Adults (≥18 years)”.

Another inclusion criterion (“Previous documentation within the past 24 months of hypertension or high blood pressure (SBP 130-179 mmHg or DBP 80-109 mmHg) from general practitioner, pharmacist or health care professional (e.g., medical assistant, physician or nurse).”) shows use of unstructured text-based descriptors for expressing the Group.characteristic values instead of explicit codes from structured terminologies. The phrase “within the past 24 months” is recognized as a timing factor and expressed within a timing element:

{ "code" : { "text" : "Defined by CodeableConcept" }, "valueCodeableConcept" : { "text" : "Previous documentation of hypertension or high blood pressure (SBP 130-179 mmHg or DBP 80-109 mmHg) from general practitioner, pharmacist or health care professional (e.g., medical assistant, physician or nurse)." }, "exclude" : false, "description" : "Previous documentation within the past 24 months of hypertension or high blood pressure (SBP 130-179 mmHg or DBP 80-109 mmHg) from general practitioner, pharmacist or health care professional (e.g., medical assistant, physician or nurse).", "timing" : [ { "text" : "within the past 24 months" } ] }

Another inclusion criterion (“Research grade blood pressure measurement (baseline mean) SBP>= 115 mmHg and DBP >= 60 mmHg”) was separated into 2 criteria (SBP and DBP) to facilitate expression in more structured data. The SBP criterion (example shown below) uses a LOINC code for mean SBP as the value of the characteristic.code element and >= 115 mmHg as the characteristic.valueQuantity element value. The “baseline” phrase in the original inclusion criterion is interpreted to mean a timing “At baseline” and that is expressed in structured form as Group.characteristic.timing.offsetDuration.value = 0. Structurally, this is using a Duration datatype for the offset[x] element within the timing element, and the quantity has a value of 0 with no units because units are irrelevant with a value of 0.

{ "code" : { "coding" : [ { "system" : "http://loinc.org", "code" : "96608-5", "display" : "Systolic blood pressure mean" } ] }, "valueQuantity" : { "value" : 115, "comparator" : ">=", "unit" : "millimeters of mercury (mm Hg)", "system" : "http://unitsofmeasure.org", "code" : "mm[Hg]" }, "exclude" : false, "description" : "Research grade blood pressure measurement (baseline mean) SBP>= 115 mmHg", "timing" : [ { "offsetDuration" : { "value" : 0 }, "text" : "At Baseline" } ] }

An exclusion criterion (“No Known contraindication to candesartan, amlodipine, indapamide or bisoprolol.”) is expressed with Group.characteristic.exclude having a value of true. This example also shows use of the codeOptions extension in the valueCodeableConcept element to provide a value set (set of 2 or more codeable concepts) to provide the value[x] part of this characteristic definition.

{ "code" : { "coding" : [ { "system" : "http://loinc.org", "code" : "64100-1", "display" : "Contraindication" } ] }, "valueCodeableConcept" : { "extension" : [ { "url" : "http://hl7.org/fhir/StructureDefinition/codeOptions", "valueCanonical" : "https://fevir.net/resources/ValueSet/383203" } ], "text" : "candesartan, amlodipine, indapamide or bisoprolol" }, "exclude" : true, "description" : "Known contraindication to candesartan, amlodipine, indapamide or bisoprolol." }

• Key Elements Table
• Differential Table
• Snapshot Table
• Statistics/References
• All

Name	Flags	Card.	Type	Description & Constraints    Filter: Bindings Constraints Obligations
Group	C	0..*	CohortDefinition	Group of multiple entities Interfaces Implemented: CanonicalResource Constraints: cnl-2
implicitRules	?!Σ	0..1	uri	A set of rules under which this content was created
contained		0..*	Resource	Contained, inline Resources
Slices for extension				Content/Rules for all slices
extension:author		0..*	ContactDetail	Who authored the artifact URL: http://hl7.org/fhir/StructureDefinition/artifact-author
extension:citeAs		0..1	markdown	Citation for this Resource URL: http://hl7.org/fhir/uv/ebm/StructureDefinition/cite-as
extension:relatesTo		0..*	(Complex)	Related artifact URL: http://hl7.org/fhir/uv/ebm/StructureDefinition/relates-to
extension:RelatesToWithQuotation		0..*	(Complex)	Related artifact with quoted portion URL: http://hl7.org/fhir/uv/ebm/StructureDefinition/relates-to-with-quotation
extension:characteristicExpression		0..1	Expression	Criteria for group membership URL: http://hl7.org/fhir/StructureDefinition/characteristicExpression
extension:publicationStatus		0..1	CodeableConcept	Publication status URL: http://hl7.org/fhir/uv/ebm/StructureDefinition/artifact-publication-status Binding: Cited Artifact Status Type (preferred)
modifierExtension	?!Σ	0..*	Extension	Extensions that cannot be ignored
status	?!Σ	0..1	code	draft | active | retired | unknown Binding: PublicationStatus (required): The lifecycle status of an artifact.
membership	Σ	1..1	code	definitional | conceptual | enumerated Binding: GroupMembershipBasis (required): The basis for membership in a group Required Pattern: definitional
combinationMethod	?!Σ	0..1	code	all-of | any-of | at-least | at-most | except-subset Binding: GroupCharacteristicCombination (required)
Documentation for this format

Terminology Bindings

Path	Status	Usage	ValueSet	Version	Source
Group.status	Base	required	PublicationStatus	📍6.0.0-ballot3	FHIR Std.
Group.membership	Base	required	Group Membership Basis	📍6.0.0-ballot3	FHIR Std.
Group.combinationMethod	Base	required	Group Characteristic Combination	📍6.0.0-ballot3	FHIR Std.

Constraints

Id	Grade	Path(s)	Description	Expression
cnl-2	error	Group	Group.type SHALL be defined if Group.membership is either 'definitional' or 'enumerated'	Group.type.exists() or (Group.membership = 'conceptual')
ele-1	error	**ALL** elements	All FHIR elements must have a @value or children	hasValue() or (children().count() > id.count())
ext-1	error	**ALL** extensions	Must have either extensions or value[x], not both	extension.exists() != value.exists()

This structure is derived from CohortDefinition

Name	Flags	Card.	Type	Description & Constraints    Filter: Bindings Constraints Obligations
Group		0..*	CohortDefinition	Group of multiple entities Interfaces Implemented: CanonicalResource
Documentation for this format

Name	Flags	Card.	Type	Description & Constraints    Filter: Bindings Constraints Obligations
Group	C	0..*	CohortDefinition	Group of multiple entities Interfaces Implemented: CanonicalResource Constraints: cnl-2
id	Σ	0..1	id	Logical id of this artifact
meta	Σ	0..1	Meta	Metadata about the resource
implicitRules	?!Σ	0..1	uri	A set of rules under which this content was created
language		0..1	code	Language of the resource content Binding: AllLanguages (required): IETF language tag for a human language Additional Bindings Purpose CommonLanguages Starter
text		0..1	Narrative	Text summary of the resource, for human interpretation This profile does not constrain the narrative in regard to content, language, or traceability to data elements
contained		0..*	Resource	Contained, inline Resources
Slices for extension		0..*	Extension	Extension Slice: Unordered, Open by value:url
extension:author		0..*	ContactDetail	Who authored the artifact URL: http://hl7.org/fhir/StructureDefinition/artifact-author
extension:citeAs		0..1	markdown	Citation for this Resource URL: http://hl7.org/fhir/uv/ebm/StructureDefinition/cite-as
extension:relatesTo		0..*	(Complex)	Related artifact URL: http://hl7.org/fhir/uv/ebm/StructureDefinition/relates-to
extension:RelatesToWithQuotation		0..*	(Complex)	Related artifact with quoted portion URL: http://hl7.org/fhir/uv/ebm/StructureDefinition/relates-to-with-quotation
extension:characteristicExpression		0..1	Expression	Criteria for group membership URL: http://hl7.org/fhir/StructureDefinition/characteristicExpression
extension:publicationStatus		0..1	CodeableConcept	Publication status URL: http://hl7.org/fhir/uv/ebm/StructureDefinition/artifact-publication-status Binding: Cited Artifact Status Type (preferred)
modifierExtension	?!Σ	0..*	Extension	Extensions that cannot be ignored
url	ΣC	0..1	uri	Canonical identifier for this Group, represented as an absolute URI (globally unique) Constraints: cnl-1
identifier	Σ	0..*	Identifier	Business Identifier for this Group
version	Σ	0..1	string	Business version of the Group
versionAlgorithm[x]	Σ	0..1		How to compare versions Binding: VersionAlgorithm (extensible)
versionAlgorithmString			string
versionAlgorithmCoding			Coding
name	Σ	0..1	string	Label for Group
title	Σ	0..1	string	Name for this Group (human friendly)
status	?!Σ	0..1	code	draft | active | retired | unknown Binding: PublicationStatus (required): The lifecycle status of an artifact.
experimental	Σ	0..1	boolean	For testing only - never for real usage
date	Σ	0..1	dateTime	Date last changed
publisher	Σ	0..1	string	Name of the publisher/steward (organization or individual)
contact	Σ	0..*	ContactDetail	Contact details for the publisher
description		0..1	markdown	Natural language description of the group
useContext	Σ	0..*	UsageContext	The context that the content is intended to support
purpose		0..1	markdown	Why this Group is defined
copyright		0..1	markdown	Use and/or publishing restrictions
copyrightLabel		0..1	string	Copyright holder and year(s)
type	Σ	0..1	code	person | animal | practitioner | device | careteam | healthcareservice | location | organization | relatedperson | specimen | medication | substance | biologicallyDerivedProduct | nutritionProduct Binding: GroupType (required): Types of resources that are part of group.
membership	Σ	1..1	code	definitional | conceptual | enumerated Binding: GroupMembershipBasis (required): The basis for membership in a group Required Pattern: definitional
code	Σ	0..1	CodeableConcept	Use of the Group (and by implication, kind of members) Binding: GroupCode (extensible): A code that describes the kind of group, which usually dictates what kind if entities can be in the group.
managingEntity	Σ	0..1	Reference(Organization | RelatedPerson | Practitioner | PractitionerRole)	Entity that is the custodian of the Group's definition
combinationMethod	?!Σ	0..1	code	all-of | any-of | at-least | at-most | except-subset Binding: GroupCharacteristicCombination (required)
combinationThreshold		0..1	positiveInt	Provides the value of "n" when "at-least" or "at-most" codes are used
characteristic	Σ	0..*	BackboneElement	Include / Exclude group members by Trait
id		0..1	string	Unique id for inter-element referencing
extension		0..*	Extension	Additional content defined by implementations
modifierExtension	?!Σ	0..*	Extension	Extensions that cannot be ignored even if unrecognized
code	Σ	1..1	CodeableConcept	Kind of characteristic Binding: ExampleCharacteristicCodes (example): List of characteristics used to describe group members; e.g. gender, age, owner, location, etc.
value[x]	Σ	1..1		Value held by characteristic
valueCodeableConcept			CodeableConcept
valueBoolean			boolean
valueQuantity			Quantity
valueRange			Range
valueReference			Reference(Any)
valueUri			uri
valueExpression			Expression
exclude	Σ	1..1	boolean	Group includes or excludes
description		0..1	markdown	Natural language description of the characteristic
method		0..*	CodeableConcept	Method for how the characteristic value was determined Binding: DefinitionMethod (example)
determinedBy[x]		0..1		Defines the characteristic
determinedByReference			Reference(Device | DeviceDefinition | DeviceMetric)
determinedByExpression			Expression
offset	?!Σ	0..1	CodeableConcept	Reference point for comparison Binding: CharacteristicOffset (example)
instances[x]	C	0..1		Number of occurrences meeting the characteristic Constraints: grp-1
instancesUnsignedInt			unsignedInt
instancesRange			Range
duration[x]		0..1		Length of time in which the characteristic is met
durationDuration			Duration
durationRange			Range
period		0..1	Period	Period over which characteristic is tested
timing		0..*	RelativeTime	Timing in which the characteristic is determined
Documentation for this format

Terminology Bindings

Path	Status	Usage	ValueSet	Version	Source
Group.language	Base	required	All Languages	📍6.0.0-ballot3	FHIR Std.
Group.versionAlgorithm[x]	Base	extensible	Version Algorithm	📍6.0.0-ballot3	FHIR Std.
Group.status	Base	required	PublicationStatus	📍6.0.0-ballot3	FHIR Std.
Group.type	Base	required	Group Type	📍6.0.0-ballot3	FHIR Std.
Group.membership	Base	required	Group Membership Basis	📍6.0.0-ballot3	FHIR Std.
Group.code	Base	extensible	Group Code	📍6.0.0-ballot3	FHIR Std.
Group.combinationMethod	Base	required	Group Characteristic Combination	📍6.0.0-ballot3	FHIR Std.
Group.characteristic.​code	Base	example	Example Characterist ic Codes	📍6.0.0-ballot3	FHIR Std.
Group.characteristic.​method	Base	example	Definition Method	📍6.0.0-ballot3	FHIR Std.
Group.characteristic.​offset	Base	example	Characteristic Offset	📍6.0.0-ballot3	FHIR Std.
Group.member.involvement	Base	example	Group Involvement	📍6.0.0-ballot3	FHIR Std.

Constraints

Id	Grade	Path(s)	Description	Expression
cnl-1	warning	Group.url	URL should not contain | or # - these characters make processing canonical references problematic	exists() implies matches('^[^|# ]+$')
cnl-2	error	Group	Group.type SHALL be defined if Group.membership is either 'definitional' or 'enumerated'	Group.type.exists() or (Group.membership = 'conceptual')
ele-1	error	**ALL** elements	All FHIR elements must have a @value or children	hasValue() or (children().count() > id.count())
ext-1	error	**ALL** extensions	Must have either extensions or value[x], not both	extension.exists() != value.exists()
grp-1	error	Group.characteristic.instances[x]	Ranges have to be positive	($this is Range) implies ((low.empty() or ((low.code.exists() or low.value.empty()) and (low.system.empty() or low.system = %ucum) and (low.code.empty() or low.code = '1') and (low.value.empty() or low.value.hasValue().not() or low.value.toString().contains('.').not()) and (low.value.empty() or low.value.hasValue().not() or low.value >= 0))) and (high.empty() or ((high.code.exists() or high.value.empty()) and (high.system.empty() or high.system = %ucum) and (high.code.empty() or high.code = '1') and (high.value.empty() or high.value.hasValue().not() or high.value.toString().contains('.').not()) and (high.value.empty() or high.value.hasValue().not() or high.value >= 0))))

Key Elements View

Name	Flags	Card.	Type	Description & Constraints    Filter: Bindings Constraints Obligations
Group	C	0..*	CohortDefinition	Group of multiple entities Interfaces Implemented: CanonicalResource Constraints: cnl-2
implicitRules	?!Σ	0..1	uri	A set of rules under which this content was created
contained		0..*	Resource	Contained, inline Resources
Slices for extension				Content/Rules for all slices
extension:author		0..*	ContactDetail	Who authored the artifact URL: http://hl7.org/fhir/StructureDefinition/artifact-author
extension:citeAs		0..1	markdown	Citation for this Resource URL: http://hl7.org/fhir/uv/ebm/StructureDefinition/cite-as
extension:relatesTo		0..*	(Complex)	Related artifact URL: http://hl7.org/fhir/uv/ebm/StructureDefinition/relates-to
extension:RelatesToWithQuotation		0..*	(Complex)	Related artifact with quoted portion URL: http://hl7.org/fhir/uv/ebm/StructureDefinition/relates-to-with-quotation
extension:characteristicExpression		0..1	Expression	Criteria for group membership URL: http://hl7.org/fhir/StructureDefinition/characteristicExpression
extension:publicationStatus		0..1	CodeableConcept	Publication status URL: http://hl7.org/fhir/uv/ebm/StructureDefinition/artifact-publication-status Binding: Cited Artifact Status Type (preferred)
modifierExtension	?!Σ	0..*	Extension	Extensions that cannot be ignored
status	?!Σ	0..1	code	draft | active | retired | unknown Binding: PublicationStatus (required): The lifecycle status of an artifact.
membership	Σ	1..1	code	definitional | conceptual | enumerated Binding: GroupMembershipBasis (required): The basis for membership in a group Required Pattern: definitional
combinationMethod	?!Σ	0..1	code	all-of | any-of | at-least | at-most | except-subset Binding: GroupCharacteristicCombination (required)
Documentation for this format

Terminology Bindings

Path	Status	Usage	ValueSet	Version	Source
Group.status	Base	required	PublicationStatus	📍6.0.0-ballot3	FHIR Std.
Group.membership	Base	required	Group Membership Basis	📍6.0.0-ballot3	FHIR Std.
Group.combinationMethod	Base	required	Group Characteristic Combination	📍6.0.0-ballot3	FHIR Std.

Constraints

Id	Grade	Path(s)	Description	Expression
cnl-2	error	Group	Group.type SHALL be defined if Group.membership is either 'definitional' or 'enumerated'	Group.type.exists() or (Group.membership = 'conceptual')
ele-1	error	**ALL** elements	All FHIR elements must have a @value or children	hasValue() or (children().count() > id.count())
ext-1	error	**ALL** extensions	Must have either extensions or value[x], not both	extension.exists() != value.exists()

Differential View

This structure is derived from CohortDefinition

Name	Flags	Card.	Type	Description & Constraints    Filter: Bindings Constraints Obligations
Group		0..*	CohortDefinition	Group of multiple entities Interfaces Implemented: CanonicalResource
Documentation for this format

Snapshot View

Name	Flags	Card.	Type	Description & Constraints    Filter: Bindings Constraints Obligations
Group	C	0..*	CohortDefinition	Group of multiple entities Interfaces Implemented: CanonicalResource Constraints: cnl-2
id	Σ	0..1	id	Logical id of this artifact
meta	Σ	0..1	Meta	Metadata about the resource
implicitRules	?!Σ	0..1	uri	A set of rules under which this content was created
language		0..1	code	Language of the resource content Binding: AllLanguages (required): IETF language tag for a human language Additional Bindings Purpose CommonLanguages Starter
text		0..1	Narrative	Text summary of the resource, for human interpretation This profile does not constrain the narrative in regard to content, language, or traceability to data elements
contained		0..*	Resource	Contained, inline Resources
Slices for extension		0..*	Extension	Extension Slice: Unordered, Open by value:url
extension:author		0..*	ContactDetail	Who authored the artifact URL: http://hl7.org/fhir/StructureDefinition/artifact-author
extension:citeAs		0..1	markdown	Citation for this Resource URL: http://hl7.org/fhir/uv/ebm/StructureDefinition/cite-as
extension:relatesTo		0..*	(Complex)	Related artifact URL: http://hl7.org/fhir/uv/ebm/StructureDefinition/relates-to
extension:RelatesToWithQuotation		0..*	(Complex)	Related artifact with quoted portion URL: http://hl7.org/fhir/uv/ebm/StructureDefinition/relates-to-with-quotation
extension:characteristicExpression		0..1	Expression	Criteria for group membership URL: http://hl7.org/fhir/StructureDefinition/characteristicExpression
extension:publicationStatus		0..1	CodeableConcept	Publication status URL: http://hl7.org/fhir/uv/ebm/StructureDefinition/artifact-publication-status Binding: Cited Artifact Status Type (preferred)
modifierExtension	?!Σ	0..*	Extension	Extensions that cannot be ignored
url	ΣC	0..1	uri	Canonical identifier for this Group, represented as an absolute URI (globally unique) Constraints: cnl-1
identifier	Σ	0..*	Identifier	Business Identifier for this Group
version	Σ	0..1	string	Business version of the Group
versionAlgorithm[x]	Σ	0..1		How to compare versions Binding: VersionAlgorithm (extensible)
versionAlgorithmString			string
versionAlgorithmCoding			Coding
name	Σ	0..1	string	Label for Group
title	Σ	0..1	string	Name for this Group (human friendly)
status	?!Σ	0..1	code	draft | active | retired | unknown Binding: PublicationStatus (required): The lifecycle status of an artifact.
experimental	Σ	0..1	boolean	For testing only - never for real usage
date	Σ	0..1	dateTime	Date last changed
publisher	Σ	0..1	string	Name of the publisher/steward (organization or individual)
contact	Σ	0..*	ContactDetail	Contact details for the publisher
description		0..1	markdown	Natural language description of the group
useContext	Σ	0..*	UsageContext	The context that the content is intended to support
purpose		0..1	markdown	Why this Group is defined
copyright		0..1	markdown	Use and/or publishing restrictions
copyrightLabel		0..1	string	Copyright holder and year(s)
type	Σ	0..1	code	person | animal | practitioner | device | careteam | healthcareservice | location | organization | relatedperson | specimen | medication | substance | biologicallyDerivedProduct | nutritionProduct Binding: GroupType (required): Types of resources that are part of group.
membership	Σ	1..1	code	definitional | conceptual | enumerated Binding: GroupMembershipBasis (required): The basis for membership in a group Required Pattern: definitional
code	Σ	0..1	CodeableConcept	Use of the Group (and by implication, kind of members) Binding: GroupCode (extensible): A code that describes the kind of group, which usually dictates what kind if entities can be in the group.
managingEntity	Σ	0..1	Reference(Organization | RelatedPerson | Practitioner | PractitionerRole)	Entity that is the custodian of the Group's definition
combinationMethod	?!Σ	0..1	code	all-of | any-of | at-least | at-most | except-subset Binding: GroupCharacteristicCombination (required)
combinationThreshold		0..1	positiveInt	Provides the value of "n" when "at-least" or "at-most" codes are used
characteristic	Σ	0..*	BackboneElement	Include / Exclude group members by Trait
id		0..1	string	Unique id for inter-element referencing
extension		0..*	Extension	Additional content defined by implementations
modifierExtension	?!Σ	0..*	Extension	Extensions that cannot be ignored even if unrecognized
code	Σ	1..1	CodeableConcept	Kind of characteristic Binding: ExampleCharacteristicCodes (example): List of characteristics used to describe group members; e.g. gender, age, owner, location, etc.
value[x]	Σ	1..1		Value held by characteristic
valueCodeableConcept			CodeableConcept
valueBoolean			boolean
valueQuantity			Quantity
valueRange			Range
valueReference			Reference(Any)
valueUri			uri
valueExpression			Expression
exclude	Σ	1..1	boolean	Group includes or excludes
description		0..1	markdown	Natural language description of the characteristic
method		0..*	CodeableConcept	Method for how the characteristic value was determined Binding: DefinitionMethod (example)
determinedBy[x]		0..1		Defines the characteristic
determinedByReference			Reference(Device | DeviceDefinition | DeviceMetric)
determinedByExpression			Expression
offset	?!Σ	0..1	CodeableConcept	Reference point for comparison Binding: CharacteristicOffset (example)
instances[x]	C	0..1		Number of occurrences meeting the characteristic Constraints: grp-1
instancesUnsignedInt			unsignedInt
instancesRange			Range
duration[x]		0..1		Length of time in which the characteristic is met
durationDuration			Duration
durationRange			Range
period		0..1	Period	Period over which characteristic is tested
timing		0..*	RelativeTime	Timing in which the characteristic is determined
Documentation for this format

Terminology Bindings

Path	Status	Usage	ValueSet	Version	Source
Group.language	Base	required	All Languages	📍6.0.0-ballot3	FHIR Std.
Group.versionAlgorithm[x]	Base	extensible	Version Algorithm	📍6.0.0-ballot3	FHIR Std.
Group.status	Base	required	PublicationStatus	📍6.0.0-ballot3	FHIR Std.
Group.type	Base	required	Group Type	📍6.0.0-ballot3	FHIR Std.
Group.membership	Base	required	Group Membership Basis	📍6.0.0-ballot3	FHIR Std.
Group.code	Base	extensible	Group Code	📍6.0.0-ballot3	FHIR Std.
Group.combinationMethod	Base	required	Group Characteristic Combination	📍6.0.0-ballot3	FHIR Std.
Group.characteristic.​code	Base	example	Example Characterist ic Codes	📍6.0.0-ballot3	FHIR Std.
Group.characteristic.​method	Base	example	Definition Method	📍6.0.0-ballot3	FHIR Std.
Group.characteristic.​offset	Base	example	Characteristic Offset	📍6.0.0-ballot3	FHIR Std.
Group.member.involvement	Base	example	Group Involvement	📍6.0.0-ballot3	FHIR Std.

Constraints

Id	Grade	Path(s)	Description	Expression
cnl-1	warning	Group.url	URL should not contain | or # - these characters make processing canonical references problematic	exists() implies matches('^[^|# ]+$')
cnl-2	error	Group	Group.type SHALL be defined if Group.membership is either 'definitional' or 'enumerated'	Group.type.exists() or (Group.membership = 'conceptual')
ele-1	error	**ALL** elements	All FHIR elements must have a @value or children	hasValue() or (children().count() > id.count())
ext-1	error	**ALL** extensions	Must have either extensions or value[x], not both	extension.exists() != value.exists()
grp-1	error	Group.characteristic.instances[x]	Ranges have to be positive	($this is Range) implies ((low.empty() or ((low.code.exists() or low.value.empty()) and (low.system.empty() or low.system = %ucum) and (low.code.empty() or low.code = '1') and (low.value.empty() or low.value.hasValue().not() or low.value.toString().contains('.').not()) and (low.value.empty() or low.value.hasValue().not() or low.value >= 0))) and (high.empty() or ((high.code.exists() or high.value.empty()) and (high.system.empty() or high.system = %ucum) and (high.code.empty() or high.code = '1') and (high.value.empty() or high.value.hasValue().not() or high.value.toString().contains('.').not()) and (high.value.empty() or high.value.hasValue().not() or high.value >= 0))))

This structure is derived from CohortDefinition

Summary

Maturity: 1