Clinical Practice Guidelines (CPG) on EBMonFHIR
1.0.1 - ci-build

Clinical Practice Guidelines (CPG) on EBMonFHIR, published by Universitätsmedizin Greifswald. This guide is not an authorized publication; it is the continuous build for version 1.0.1 built by the FHIR (HL7® FHIR® Standard) CI Build. This version is based on the current content of https://github.com/CEOsys/cpg-on-ebm-on-fhir/ and changes regularly. See the Directory of published versions

Resource Profile: StudyCohort - Detailed Descriptions

Draft as of 2022-05-10

Definitions for the study-cohort resource profile.

Guidance on how to interpret the contents of this table can be found here

0. Group

Guidance on how to interpret the contents of this table can be found here

0. Group
Definition

Represents a defined collection of entities that may be discussed or acted upon collectively but which are not expected to act collectively, and are not formally or legally recognized; i.e. a collection of entities that isn't an Organization.

ShortGroup of multiple entities
Comments

If both Group.characteristic and Group.member are present, then the members are the individuals who were found who met the characteristic. It's possible that there might be other candidate members who meet the characteristic and aren't (yet) in the list. All members SHALL have the listed characteristics.

Control0..*
Is Modifierfalse
Must Supportfalse
Summaryfalse
Invariantsdom-2: If the resource is contained in another resource, it SHALL NOT contain nested Resources (contained.contained.empty())
dom-3: If the resource is contained in another resource, it SHALL be referred to from elsewhere in the resource or SHALL refer to the containing resource (contained.where((('#'+id in (%resource.descendants().reference | %resource.descendants().ofType(canonical) | %resource.descendants().ofType(uri) | %resource.descendants().ofType(url))) or descendants().where(reference = '#').exists() or descendants().where(ofType(canonical) = '#').exists() or descendants().where(ofType(canonical) = '#').exists()).not()).trace('unmatched', id).empty())
dom-4: If a resource is contained in another resource, it SHALL NOT have a meta.versionId or a meta.lastUpdated (contained.meta.versionId.empty() and contained.meta.lastUpdated.empty())
dom-5: If a resource is contained in another resource, it SHALL NOT have a security label (contained.meta.security.empty())
dom-6: A resource should have narrative for robust management (text.`div`.exists())
2. Group.implicitRules
Definition

A reference to a set of rules that were followed when the resource was constructed, and which must be understood when processing the content. Often, this is a reference to an implementation guide that defines the special rules along with other profiles etc.

ShortA set of rules under which this content was created
Comments

Asserting this rule set restricts the content to be only understood by a limited set of trading partners. This inherently limits the usefulness of the data in the long term. However, the existing health eco-system is highly fractured, and not yet ready to define, collect, and exchange data in a generally computable sense. Wherever possible, implementers and/or specification writers should avoid using this element. Often, when used, the URL is a reference to an implementation guide that defines these special rules as part of its narrative along with other profiles, value sets, etc.

Control0..1
Typeuri
Is Modifiertrue because This element is labeled as a modifier because the implicit rules may provide additional knowledge about the resource that modifies its meaning or interpretation
Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
Must Supportfalse
Summarytrue
Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
4. Group.contained
Definition

These resources do not have an independent existence apart from the resource that contains them - they cannot be identified independently, nor can they have their own independent transaction scope. This is allowed to be a Parameters resource if and only if it is referenced by a resource that provides context/meaning.

ShortContained, inline Resources
Comments

This should never be done when the content can be identified properly, as once identification is lost, it is extremely difficult (and context dependent) to restore it again. Contained resources may have profiles and tags in their meta elements, but SHALL NOT have security labels.

Control0..*
This element is affected by the following invariants: dom-2, dom-4, dom-3, dom-5
TypeResource
Is Modifierfalse
Must Supportfalse
Summaryfalse
Alternate Namesinline resources, anonymous resources, contained resources
6. Group.modifierExtension
Definition

May be used to represent additional information that is not part of the basic definition of the resource and that modifies the understanding of the element that contains it and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. To make the use of extensions safe and managable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer is allowed to define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. Applications processing a resource are required to check for modifier extensions.

Modifier extensions SHALL NOT change the meaning of any elements on Resource or DomainResource (including cannot change the meaning of modifierExtension itself).

ShortExtensions that cannot be ignored
Comments

There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

Control0..*
TypeExtension
Is Modifiertrue because Modifier extensions are expected to modify the meaning or interpretation of the resource that contains them
Must Supportfalse
Summarytrue
Requirements

Modifier extensions allow for extensions that cannot be safely ignored to be clearly distinguished from the vast majority of extensions which can be safely ignored. This promotes interoperability by eliminating the need for implementers to prohibit the presence of extensions. For further information, see the definition of modifier extensions.

Alternate Namesextensions, user content
Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
8. Group.active
Definition

Indicates whether the record for the group is available for use or is merely being retained for historical purposes.

ShortWhether this group's record is in active use
Control0..1
Typeboolean
Is Modifiertrue because This element is labelled as a modifier because it is a status element that can indicate that a record should not be treated as valid
Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
Must Supportfalse
Summarytrue
Requirements

Need to be able to mark a group record as not to be used because it was created in error or is otherwise no longer available (e.g. a herd that no longer exists).

Meaning if MissingThis resource is generally assumed to be active if no value is provided for the active element
Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
10. Group.type
Definition

Identifies the broad classification of the kind of resources the group includes.

Shortperson | animal | practitioner | device | careteam | healthcareservice | location | organization | relatedperson | specimen
Comments

Group members SHALL be of the appropriate resource type (Patient for person or animal; or Practitioner, PractitionerRole, Device, CareTeam, HealthcareService, Location, Organization, RelatedPerson, or Specimen for the other types.), or a Group of the resources of the appropriate type.

Control1..1
BindingThe codes SHALL be taken from GroupTypehttp://hl7.org/fhir/ValueSet/group-type|5.0.0
(required to http://hl7.org/fhir/ValueSet/group-type|5.0.0)

Types of resources that are part of group.

Typecode
Is Modifierfalse
Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
Must Supportfalse
Summarytrue
Requirements

Identifies what type of resources the group is made up of.

Pattern Valueperson
Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
12. Group.membership
Definition

Basis for membership in the Group:

  • 'definitional': The Group.characteristics specified are both necessary and sufficient to determine membership. All entities that meet the criteria are considered to be members of the group, whether referenced by the group or not. If members are present, they are individuals that happen to be known as meeting the Group.characteristics. The list cannot be presumed to be complete.
  • 'enumerated': The Group.characteristics are necessary but not sufficient to determine membership. Membership is determined by being listed as one of the Group.member.
Shortdefinitional | enumerated
Control1..1
BindingThe codes SHALL be taken from GroupMembershipBasishttp://hl7.org/fhir/ValueSet/group-membership-basis|5.0.0
(required to http://hl7.org/fhir/ValueSet/group-membership-basis|5.0.0)

The basis for membership in a group

Typecode
Is Modifierfalse
Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
Must Supportfalse
Summarytrue
Requirements

There are use-cases for groups that define specific collections of individuals, and other groups that define "types" of intended individuals. The requirements for both kinds of groups are similar, so we use a single resource, distinguished by this element.

Pattern Valuedefinitional
Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
14. Group.quantity
Definition

A count of the number of resource instances that are part of the group.

ShortNumber of members
Comments

Note that the quantity may be less than the number of members if some of the members are not active.

Control10..1
TypeunsignedInt
Is Modifierfalse
Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
Must Supporttrue
Summarytrue
Requirements

Group size is a common defining characteristic.

Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
16. Group.characteristic
Definition

Identifies traits whose presence r absence is shared by members of the group.

ShortInclude / Exclude group members by Trait
Comments

All the identified characteristics must be true for an entity to a member of the group.

Control0..0*
TypeBackboneElement
Is Modifierfalse
Must Supportfalse
Summarytrue
Requirements

Needs to be a generic mechanism for identifying what individuals can be part of a group.

Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))

Guidance on how to interpret the contents of this table can be found here

0. Group
Definition

Represents a defined collection of entities that may be discussed or acted upon collectively but which are not expected to act collectively, and are not formally or legally recognized; i.e. a collection of entities that isn't an Organization.

ShortGroup of multiple entities
Comments

If both Group.characteristic and Group.member are present, then the members are the individuals who were found who met the characteristic. It's possible that there might be other candidate members who meet the characteristic and aren't (yet) in the list. All members SHALL have the listed characteristics.

Control0..*
Is Modifierfalse
Must Supportfalse
Summaryfalse
Invariantsdom-2: If the resource is contained in another resource, it SHALL NOT contain nested Resources (contained.contained.empty())
dom-3: If the resource is contained in another resource, it SHALL be referred to from elsewhere in the resource or SHALL refer to the containing resource (contained.where((('#'+id in (%resource.descendants().reference | %resource.descendants().ofType(canonical) | %resource.descendants().ofType(uri) | %resource.descendants().ofType(url))) or descendants().where(reference = '#').exists() or descendants().where(ofType(canonical) = '#').exists() or descendants().where(ofType(canonical) = '#').exists()).not()).trace('unmatched', id).empty())
dom-4: If a resource is contained in another resource, it SHALL NOT have a meta.versionId or a meta.lastUpdated (contained.meta.versionId.empty() and contained.meta.lastUpdated.empty())
dom-5: If a resource is contained in another resource, it SHALL NOT have a security label (contained.meta.security.empty())
dom-6: A resource should have narrative for robust management (text.`div`.exists())
2. Group.id
Definition

The logical id of the resource, as used in the URL for the resource. Once assigned, this value never changes.

ShortLogical id of this artifact
Comments

Within the context of the FHIR RESTful interactions, the resource has an id except for cases like the create and conditional update. Otherwise, the use of the resouce id depends on the given use case.

Control0..1
Typeid
Is Modifierfalse
Must Supportfalse
Summarytrue
4. Group.meta
Definition

The metadata about the resource. This is content that is maintained by the infrastructure. Changes to the content might not always be associated with version changes to the resource.

ShortMetadata about the resource
Control0..1
TypeMeta
Is Modifierfalse
Must Supportfalse
Summarytrue
Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
6. Group.implicitRules
Definition

A reference to a set of rules that were followed when the resource was constructed, and which must be understood when processing the content. Often, this is a reference to an implementation guide that defines the special rules along with other profiles etc.

ShortA set of rules under which this content was created
Comments

Asserting this rule set restricts the content to be only understood by a limited set of trading partners. This inherently limits the usefulness of the data in the long term. However, the existing health eco-system is highly fractured, and not yet ready to define, collect, and exchange data in a generally computable sense. Wherever possible, implementers and/or specification writers should avoid using this element. Often, when used, the URL is a reference to an implementation guide that defines these special rules as part of its narrative along with other profiles, value sets, etc.

Control0..1
Typeuri
Is Modifiertrue because This element is labeled as a modifier because the implicit rules may provide additional knowledge about the resource that modifies its meaning or interpretation
Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
Must Supportfalse
Summarytrue
Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
8. Group.language
Definition

The base language in which the resource is written.

ShortLanguage of the resource content
Comments

Language is provided to support indexing and accessibility (typically, services such as text to speech use the language tag). The html language tag in the narrative applies to the narrative. The language tag on the resource may be used to specify the language of other presentations generated from the data in the resource. Not all the content has to be in the base language. The Resource.language should not be assumed to apply to the narrative automatically. If a language is specified, it should it also be specified on the div element in the html (see rules in HTML5 for information about the relationship between xml:lang and the html lang attribute).

Control0..1
BindingThe codes SHALL be taken from AllLanguages
(required to http://hl7.org/fhir/ValueSet/all-languages|5.0.0)

IETF language tag for a human language

Typecode
Is Modifierfalse
Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
Must Supportfalse
Summaryfalse
Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
10. Group.text
Definition

A human-readable narrative that contains a summary of the resource and can be used to represent the content of the resource to a human. The narrative need not encode all the structured data, but is required to contain sufficient detail to make it "clinically safe" for a human to just read the narrative. Resource definitions may define what content should be represented in the narrative to ensure clinical safety.

ShortText summary of the resource, for human interpretation
Comments

Contained resources do not have a narrative. Resources that are not contained SHOULD have a narrative. In some cases, a resource may only have text with little or no additional discrete data (as long as all minOccurs=1 elements are satisfied). This may be necessary for data from legacy systems where information is captured as a "text blob" or where text is additionally entered raw or narrated and encoded information is added later.

Control0..1
This element is affected by the following invariants: dom-6
TypeNarrative
Is Modifierfalse
Must Supportfalse
Summaryfalse
Alternate Namesnarrative, html, xhtml, display
Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
12. Group.contained
Definition

These resources do not have an independent existence apart from the resource that contains them - they cannot be identified independently, nor can they have their own independent transaction scope. This is allowed to be a Parameters resource if and only if it is referenced by a resource that provides context/meaning.

ShortContained, inline Resources
Comments

This should never be done when the content can be identified properly, as once identification is lost, it is extremely difficult (and context dependent) to restore it again. Contained resources may have profiles and tags in their meta elements, but SHALL NOT have security labels.

Control0..*
This element is affected by the following invariants: dom-2, dom-4, dom-3, dom-5
TypeResource
Is Modifierfalse
Must Supportfalse
Summaryfalse
Alternate Namesinline resources, anonymous resources, contained resources
14. Group.extension
Definition

May be used to represent additional information that is not part of the basic definition of the resource. To make the use of extensions safe and managable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension.

ShortAdditional content defined by implementations
Comments

There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

Control0..*
TypeExtension
Is Modifierfalse
Must Supportfalse
Summaryfalse
Alternate Namesextensions, user content
Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
16. Group.modifierExtension
Definition

May be used to represent additional information that is not part of the basic definition of the resource and that modifies the understanding of the element that contains it and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. To make the use of extensions safe and managable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer is allowed to define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. Applications processing a resource are required to check for modifier extensions.

Modifier extensions SHALL NOT change the meaning of any elements on Resource or DomainResource (including cannot change the meaning of modifierExtension itself).

ShortExtensions that cannot be ignored
Comments

There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

Control0..*
TypeExtension
Is Modifiertrue because Modifier extensions are expected to modify the meaning or interpretation of the resource that contains them
Must Supportfalse
Summarytrue
Requirements

Modifier extensions allow for extensions that cannot be safely ignored to be clearly distinguished from the vast majority of extensions which can be safely ignored. This promotes interoperability by eliminating the need for implementers to prohibit the presence of extensions. For further information, see the definition of modifier extensions.

Alternate Namesextensions, user content
Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
18. Group.identifier
Definition

Business identifiers assigned to this participant by one of the applications involved. These identifiers remain constant as the resource is updated and propagates from server to server.

ShortBusiness Identifier for this Group
Comments

Note: This is a business identifier, not a resource identifier (see discussion). It is best practice for the identifier to only appear on a single resource instance, however business practices may occasionally dictate that multiple resource instances with the same identifier can exist - possibly even with different resource types.

NoteThis is a business identifier, not a resource identifier (see discussion)
Control0..*
TypeIdentifier
Is Modifierfalse
Must Supportfalse
Summarytrue
Requirements

Allows identification of the group as it is known by various participating systems and in a way that remains consistent across servers.

Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
20. Group.active
Definition

Indicates whether the record for the group is available for use or is merely being retained for historical purposes.

ShortWhether this group's record is in active use
Control0..1
Typeboolean
Is Modifiertrue because This element is labelled as a modifier because it is a status element that can indicate that a record should not be treated as valid
Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
Must Supportfalse
Summarytrue
Requirements

Need to be able to mark a group record as not to be used because it was created in error or is otherwise no longer available (e.g. a herd that no longer exists).

Meaning if MissingThis resource is generally assumed to be active if no value is provided for the active element
Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
22. Group.type
Definition

Identifies the broad classification of the kind of resources the group includes.

Shortperson | animal | practitioner | device | careteam | healthcareservice | location | organization | relatedperson | specimen
Comments

Group members SHALL be of the appropriate resource type (Patient for person or animal; or Practitioner, PractitionerRole, Device, CareTeam, HealthcareService, Location, Organization, RelatedPerson, or Specimen for the other types.), or a Group of the resources of the appropriate type.

Control1..1
BindingThe codes SHALL be taken from GroupType
(required to http://hl7.org/fhir/ValueSet/group-type|5.0.0)

Types of resources that are part of group.

Typecode
Is Modifierfalse
Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
Must Supportfalse
Summarytrue
Requirements

Identifies what type of resources the group is made up of.

Pattern Valueperson
Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
24. Group.membership
Definition

Basis for membership in the Group:

  • 'definitional': The Group.characteristics specified are both necessary and sufficient to determine membership. All entities that meet the criteria are considered to be members of the group, whether referenced by the group or not. If members are present, they are individuals that happen to be known as meeting the Group.characteristics. The list cannot be presumed to be complete.
  • 'enumerated': The Group.characteristics are necessary but not sufficient to determine membership. Membership is determined by being listed as one of the Group.member.
Shortdefinitional | enumerated
Control1..1
BindingThe codes SHALL be taken from GroupMembershipBasis
(required to http://hl7.org/fhir/ValueSet/group-membership-basis|5.0.0)

The basis for membership in a group

Typecode
Is Modifierfalse
Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
Must Supportfalse
Summarytrue
Requirements

There are use-cases for groups that define specific collections of individuals, and other groups that define "types" of intended individuals. The requirements for both kinds of groups are similar, so we use a single resource, distinguished by this element.

Pattern Valuedefinitional
Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
26. Group.code
Definition

Provides a specific type of resource the group includes; e.g. "cow", "syringe", etc.

ShortKind of Group members
Comments

This would generally be omitted for Person resources.

Control0..1
Binding

Kind of particular resource; e.g. cow, syringe, lake, etc.

TypeCodeableConcept
Is Modifierfalse
Must Supportfalse
Summarytrue
Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
28. Group.name
Definition

A label assigned to the group for human identification and communication.

ShortLabel for Group
Control0..1
Typestring
Is Modifierfalse
Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
Must Supportfalse
Summarytrue
Requirements

Used to identify the group in human communication.

Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
30. Group.description
Definition

Explanation of what the group represents and how it is intended to be used.

ShortNatural language description of the group
Control0..1
Typemarkdown
Is Modifierfalse
Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
Must Supportfalse
Summaryfalse
Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
32. Group.quantity
Definition

A count of the number of resource instances that are part of the group.

ShortNumber of members
Comments

Note that the quantity may be less than the number of members if some of the members are not active.

Control1..1
TypeunsignedInt
Is Modifierfalse
Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
Must Supporttrue
Summarytrue
Requirements

Group size is a common defining characteristic.

Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
34. Group.managingEntity
Definition

Entity responsible for defining and maintaining Group characteristics and/or registered members.

ShortEntity that is the custodian of the Group's definition
Comments

This does not strictly align with ownership of a herd or flock, but may suffice to represent that relationship in simple cases. More complex cases will require an extension.

Control0..1
TypeReference(Organization, RelatedPerson, Practitioner, PractitionerRole)
Is Modifierfalse
Must Supportfalse
Summarytrue
Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
36. Group.characteristic
Definition

Identifies traits whose presence r absence is shared by members of the group.

ShortInclude / Exclude group members by Trait
Comments

All the identified characteristics must be true for an entity to a member of the group.

Control0..0
TypeBackboneElement
Is Modifierfalse
Must Supportfalse
Summarytrue
Requirements

Needs to be a generic mechanism for identifying what individuals can be part of a group.

Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
45. Group.member
Definition

Identifies the resource instances that are members of the group.

ShortWho or what is in group
Control0..*
TypeBackboneElement
Is Modifierfalse
Must Supportfalse
Summaryfalse
Requirements

Often the only thing of interest about a group is "who's in it".

Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
47. Group.member.id
Definition

Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.

ShortUnique id for inter-element referencing
Control0..1
This element is affected by the following invariants: ele-1
Typestring
Is Modifierfalse
XML FormatIn the XML format, this property is represented as an attribute.
Summaryfalse
49. Group.member.extension
Definition

May be used to represent additional information that is not part of the basic definition of the element. To make the use of extensions safe and managable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension.

ShortAdditional content defined by implementations
Comments

There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

Control0..*
TypeExtension
Is Modifierfalse
Summaryfalse
Alternate Namesextensions, user content
Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
51. Group.member.modifierExtension
Definition

May be used to represent additional information that is not part of the basic definition of the element and that modifies the understanding of the element in which it is contained and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. To make the use of extensions safe and managable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. Applications processing a resource are required to check for modifier extensions.

Modifier extensions SHALL NOT change the meaning of any elements on Resource or DomainResource (including cannot change the meaning of modifierExtension itself).

ShortExtensions that cannot be ignored even if unrecognized
Comments

There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

Control0..*
TypeExtension
Is Modifiertrue because Modifier extensions are expected to modify the meaning or interpretation of the element that contains them
Summarytrue
Requirements

Modifier extensions allow for extensions that cannot be safely ignored to be clearly distinguished from the vast majority of extensions which can be safely ignored. This promotes interoperability by eliminating the need for implementers to prohibit the presence of extensions. For further information, see the definition of modifier extensions.

Alternate Namesextensions, user content, modifiers
Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
53. Group.member.entity
Definition

A reference to the entity that is a member of the group. Must be consistent with Group.type. If the entity is another group, then the type must be the same.

ShortReference to the group member
Control1..1
TypeReference(CareTeam, Device, Group, HealthcareService, Location, Organization, Patient, Practitioner, PractitionerRole, RelatedPerson, Specimen)
Is Modifierfalse
Must Supportfalse
Summaryfalse
Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
55. Group.member.period
Definition

The period that the member was in the group, if known.

ShortPeriod member belonged to the group
Control0..1
TypePeriod
Is Modifierfalse
Must Supportfalse
Summaryfalse
Requirements

Need to track who was in a group at a particular time.

Meaning if MissingThe member is in the group at this time
Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
57. Group.member.inactive
Definition

A flag to indicate that the member is no longer in the group, but previously may have been a member.

ShortIf member is no longer in group
Control0..1
Typeboolean
Is Modifierfalse
Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
Must Supportfalse
Summaryfalse
Requirements

Sometimes you don't know when someone stopped being in a group, but not when.

Meaning if MissingMembers are considered active unless explicitly specified otherwise
Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))