Generated Narrative: StructureDefinition IHE.BasicAudit.MHD5.Query Name Flags Card. Type Description & Constraints AuditEvent 0..* AuditEvent Record of an event #xD; Slices for category 1..* CodeableConcept Type/identifier of event Slice: Unordered, Open by value:$this #xD; category:anySearch 1..1 CodeableConcept Type/identifier of event Binding: all Searches (required) #xD; code 1..1 CodeableConcept Specific type of event Required Pattern: At least the following #xD; coding 1..* Coding Code defined by a terminology system Fixed Value: (Complex) #xD; system 1..1 uri Identity of the terminology system Fixed Value: http://terminology.hl7.org/CodeSystem/audit-event-type #xD; code 1..1 code Symbol in syntax defined by the system Fixed Value: rest #xD; action 0..1 code Type of action performed during the event Required Pattern: E #xD; outcome #xD; code 1..1 Coding Whether the event succeeded or failed Required Pattern: At least the following #xD; system 1..1 uri Identity of the terminology system Fixed Value: http://terminology.hl7.org/CodeSystem/audit-event-outcome #xD; code 1..1 code Symbol in syntax defined by the system Fixed Value: 0 #xD; Slices for agent 2..* BackboneElement Actor involved in the event Slice: Unordered, Open by value:type #xD; agent:client 1..1 BackboneElement Actor involved in the event #xD; type 1..1 CodeableConcept How agent participated Required Pattern: At least the following #xD; coding 1..* Coding Code defined by a terminology system Fixed Value: (Complex) #xD; system 1..1 uri Identity of the terminology system Fixed Value: http://dicom.nema.org/resources/ontology/DCM #xD; code 1..1 code Symbol in syntax defined by the system Fixed Value: 110153 #xD; network[x] 1..1 Reference(Endpoint), uri, string This agent network location for the activity #xD; agent:server 1..1 BackboneElement Actor involved in the event #xD; type 1..1 CodeableConcept How agent participated Required Pattern: At least the following #xD; coding 1..* Coding Code defined by a terminology system Fixed Value: (Complex) #xD; system 1..1 uri Identity of the terminology system Fixed Value: http://dicom.nema.org/resources/ontology/DCM #xD; code 1..1 code Symbol in syntax defined by the system Fixed Value: 110152 #xD; network[x] 1..1 Reference(Endpoint), uri, string This agent network location for the activity #xD; agent:user 0..1 BackboneElement Actor involved in the event #xD; type 1..1 CodeableConcept How agent participated Required Pattern: At least the following #xD; coding 1..* Coding Code defined by a terminology system Fixed Value: (Complex) #xD; system 1..1 uri Identity of the terminology system Fixed Value: http://terminology.hl7.org/CodeSystem/v3-ParticipationType #xD; code 1..1 code Symbol in syntax defined by the system Fixed Value: IRCP #xD; role S 0..* CodeableConcept Agent role in the event #xD; requestor 0..1 boolean Whether user is initiator Required Pattern: true #xD; policy S 0..* uri Policy that authorized the agent participation in the event #xD; network[x] 0..0 This agent network location for the activity #xD; source S 1..1 BackboneElement Audit Event Reporter #xD; Slices for entity 1..* BackboneElement Data or objects used Slice: Unordered, Open by value:role #xD; entity:transaction 0..1 BackboneElement Data or objects used #xD; what #xD; identifier #xD; value 1..1 string the value of X-Request-Id #xD; role 1..1 CodeableConcept What role the entity played Required Pattern: At least the following #xD; coding 1..* Coding Code defined by a terminology system Fixed Value: (Complex) #xD; system 1..1 uri Identity of the terminology system Fixed Value: https://profiles.ihe.net/ITI/MHD/CodeSystem/BasicAuditEntityType #xD; code 1..1 code Symbol in syntax defined by the system Fixed Value: XrequestId #xD; entity:query 1..1 BackboneElement Data or objects used #xD; what 0..0 Specific instance of resource #xD; role 1..1 CodeableConcept What role the entity played Required Pattern: At least the following #xD; coding 1..* Coding Code defined by a terminology system Fixed Value: (Complex) #xD; system 1..1 uri Identity of the terminology system Fixed Value: http://terminology.hl7.org/CodeSystem/object-role #xD; code 1..1 code Symbol in syntax defined by the system Fixed Value: 24 #xD; securityLabel 0..* CodeableConcept may contain the security labels on the Bundle search set returned #xD; query 1..1 base64Binary Query parameters #xD; Documentation for this format
IHE IT Infrastructure Technical Committee
A basic AuditEvent profile for when a RESTful Query / Search action happens successfully. - Given a RESTful Query is requested - And the request does not have a Patient subject indicated - The requestor logging the event would potentially not know they have requested Patient specific data - The data objects may not be patient specific kind of objects - when the request is Patient specific then [PatientQuery](StructureDefinition-IHE.BasicAudit.MHD5.PatientQuery.html) is used - And the request is authorized - Authorization failures should follow [FHIR core Access Denied](http://hl7.org/fhir/security.html#AccessDenied) - When successful - Note a failure AuditEvent may follow this pattern, but would not be a successful outcome and should have an OperationOutcome - Note success may result in zero or more results. The number of results and the content of the results are not recorded. - And the results are not Patient specific - when the results are Patient specific then [PatientQuery](StructureDefinition-IHE.BasicAudit.MHD5.PatientQuery.html) are used - Then the AuditEvent recorded will conform - The raw search request is base64 encoded and placed in the .entity[query].query element. The base64 encoding of the raw search request enables preserving exactly what was requested, including possibly malicious patterns. This enables detection of malicious or malformed requests. - The cleaned search may be recorded (not base64) in the .entity[query].description. The cleaned search request would have removed parameters that were not understood/supported. The cleaned search request in the .description element enables more efficient processing. Note: the pattern defined in DICOM and IHE have the client is identified as the Source Role ID, and the server is identified as the Destination Role ID. This represents the query parameters are flowing from the client to the server. This may not be so obvious, as the data actually flows the opposite direction. This pattern is established and thus followed here.
A record of an event relevant for purposes such as operations, privacy, security, maintenance, and performance analysis.
If the resource is contained in another resource, it SHALL NOT contain nested Resources
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()
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()
If a resource is contained in another resource, it SHALL NOT have a security label
When a resource has no narrative, only systems that fully understand the data can display the resource to a human safely. Including a human readable representation in the resource makes for a much more robust eco-system and cheaper handling of resources by intermediary systems. Some ecosystems restrict distribution of resources to only those systems that do fully understand the resources, and as a consequence implementers may believe that the narrative is superfluous. However experience shows that such eco-systems often open up to new participants over time.
A resource should have narrative for robust management
Entity, Role, or Act,ControlAct[moodCode=EVN]
The logical id of the resource, as used in the URL for the resource. Once assigned, this value never changes.
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.
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.
All FHIR elements must have a @value or children
hasValue() or (children().count() > id.count())
A set of rules under which this content was created
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.
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.
This element is labeled as a modifier because the implicit rules may provide additional knowledge about the resource that modifies its meaning or interpretation
The base language in which the resource is written.
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).
Text summary of the resource, for human interpretation
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.
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.
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.
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.
Additional content defined by implementations
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.
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.
Must have either extensions or value[x], not both
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).
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](http://hl7.org/fhir/R5/extensibility.html#modifierExtension).
Modifier extensions are expected to modify the meaning or interpretation of the resource that contains them
Codes that classify the general type of event that happened.
.code (type, subtype and action are pre-coordinated or sent as translations)
Describes what happened. The most specific code for the event.
This field enables queries of messages by implementation-defined event categories.
Type of action performed during the event
Indicator for type of action performed during the event that generated the audit.
This broadly indicates what kind of action was done on the AuditEvent.entity by the AuditEvent.agent.
emergency | alert | critical | error | warning | notice | informational | debug
Indicates and enables segmentation of various severity including debugging from critical.
ATNA will map this to the SYSLOG PRI element.
This is in the SysLog header, PRI. http://tools.ietf.org/html/rfc5424#appendix-A.3
The time or period during which the activity occurred.
The time or period can be a little arbitrary; where possible, the time should correspond to human assessment of the activity time.
In a distributed system, some sort of common time base (e.g. an NTP [RFC1305] server) is a good implementation tactic.
This ties an event to a specific date and time. Security audits typically require a consistent time base (e.g. UTC), to eliminate time-zone issues arising from geographical distribution.
Indicates whether the event succeeded or failed. A free text descripiton can be given in outcome.text.
In some cases a "success" may be partial, for example, an incomplete or interrupted transfer of a radiological study. For the purpose of establishing accountability, these distinctions are not relevant.
when a code is given there must be one code from the given codeSystem, and may be other equivilant codes from other codeSystems (for example http response codes such as 2xx, 4xx, or 5xx).
Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.
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.
Extensions that cannot be ignored even if unrecognized
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).
Modifier extensions are expected to modify the meaning or interpretation of the element that contains them
Indicates whether the event succeeded or failed.
when a code is given there must be one code from the given codeSystem.
EventOutcomeIndicator EventOutcomeIndicator
Additional details about the error. This may be a text description of the error or a system code that identifies the error.
A human readable description of the error issue SHOULD be placed in details.text.
A code that provides details as the exact issue.
The authorization (e.g., PurposeOfUse) that was used during the event being recorded.
Use AuditEvent.agent.authorization when you know that it is specific to the agent, otherwise use AuditEvent.authorization. For example, during a machine-to-machine transfer it might not be obvious to the audit system who caused the event, but it does know why.
Record of any relevant security context, not restricted to purposeOfUse valueSet. May include security compartments, refrain, obligation, or other security tags.
The authorized purposeOfUse for the activity.
* .reasonCode [ControlActReason when Act.class = CACT Control Act] *.outboundRelationship[typeCode=RSON].target
Workflow authorization within which this event occurred
Allows tracing of authorizatino for the events and tracking whether proposals/recommendations were acted upon.
The patient is the subject of the data used/created/updated/deleted during the activity
The patient element is available to enable deterministic tracking of activities that involve the patient as the subject of the data used in an activity.
When the .patient is populated it shall be accurate to the subject of the used data. The .patient shall not be populated when the used data used/created/updated/deleted (.entity) by the activity does not involve a subject. Note that when the patient is an agent, they will be recorded as an agent. When the Patient resource is Created, Updated, or Deleted it will be recorded as an entity.
Encounter within which this event occurred or which the event is tightly associated
This will typically be the encounter the event occurred, but some events may be initiated prior to or after the official completion of an encounter but still be tied to the context of the encounter (e.g. pre-admission lab tests).
An actor taking an active role in the event or activity that is logged.
Several agents may be associated (i.e. have some responsibility for an activity) with an event or activity. For example, an activity may be initiated by one user for other users or involve more than one user. However, only one user may be the initiator/requestor for the activity. When a network are used in an event being recorded, there should be distinct agent elements for the known actors using the network. The agent with a network detail would be the responsible agent for use of that network.
An agent can be a person, an organization, software, device, or other actors that may be ascribed responsibility.
The Functional Role of the user when performing the event.
For example: assembler, author, prescriber, signer, investigator, etc.
Functional roles reflect functional aspects of relationships between entities. Functional roles are bound to the realization/performance of acts, where actions might be concatenated to an activity or even to a process. This element will hold the functional role that the agent played in the activity that is the focus of this Provenance. Where an agent played multiple functional roles, they will be listed as multiple .agent elements representing each functional participation. See ISO 21298:2018 - Health Informatics - Functional and structural roles, and ISO 22600-2:2014 - Health Informatics - Privilege Management and Access Control - Part 2: formal models.
The Participation type of the agent to the event.
The structural roles of the agent indicating the agent's competency. The security role enabling the agent with respect to the activity.
For example: Chief-of-Radiology, Nurse, Physician, Medical-Student, etc.
Structural roles reflect the structural aspects of relationships between entities. Structural roles describe prerequisites, feasibilities, or competences for acts. Functional roles reflect functional aspects of relationships between entities. Functional roles are bound to the realization/performance of acts, where actions might be concatenated to an activity or even to a process. See ISO 21298:2018 - Health Informatics - Functional and structural roles, and ISO 22600-2:2014 - Health Informatics - Privilege Management and Access Control - Part 2: formal models..
What security role enabled the agent to participate in the event.
Reference to who this agent is that was involved in the event.
Where a User ID is available it will go into who.identifier. Where a name of the user (human readable) it will go into who.display.
This field ties an audit event to a specific resource or identifier.
Indicator that the user is or is not the requestor, or initiator, for the event being audited.
There can only be one initiator. If the initiator is not clear, then do not choose any one agent as the initiator.
This value is used to distinguish between requestor-users and recipient-users. For example, one person may initiate a report-output to be sent to another user.
If participation.typeCode was author, then true
The agent location when the event occurred
Where the agent location is known, the agent location when the event occurred.
* Role.Class =SDLOC *Role.Code = ServiceDeliveryLocationRoleType *Entity.Code = PlaceEntityType = df.Types of places for Entity.Class = PLC *EntityClass = PLC = df.A physical place or site with its containing structure. May be natural or man-made. The geographic position of a place might or might not be constant.
Policy that authorized the agent participation in the event
Where the policy(ies) are known that authorized the agent participation in the event. Typically, a single activity may have multiple applicable policies, such as patient consent, guarantor funding, etc. The policy would also indicate the security token used.
For example: Where an OAuth token authorizes, the unique identifier from the OAuth token is placed into the policy element Where a policy engine (e.g. XACML) holds policy logic, the unique policy identifier is placed into the policy element.
This value is used retrospectively to determine the authorization policies.
This agent network location for the activity
When the event utilizes a network there should be an agent describing the local system, and an agent describing remote system, with the network interface details.
When remote network endpoint is known, another agent representing the remote agent would indicate the remote network endpoint used. Convention is to indicate data flowing from Source to Destination. The convention for Search, given data flows both ways (query parameters vs results), is to have the Source as the initiator of the Search Transaction, and the Destination the responder to the Search transaction.
When a network protocol is used the endpoint is associated with the agent most directly using the endpoint. This is usually the software agent that has implemented the application level protocol. Preference is to define network in terms of a Reference(Endpoint), or URI; use string only when address or hostname is all that is known. When encoding using string it is best to encode using the formal canonical host name, but if you can't, then you can encode numeric in Literal address form using square brackets '[]' as a v4 string (in dotted notation), or v6 string (in colon notation).
NetworkAccessPointID and NetworkAccessPointTypeCode
Use AuditEvent.agent.authorization when you know that is specific to the agent, otherwise use AuditEvent.authorization. For example, during a machine-to-machine transfer it might not be obvious to the audit system who caused the event, but it does know why.
*.reasonCode [ActHealthInformationPurposeOfUseReason codes/v:PurposeOfUse (2.16.840.1.113883.1.11.20448) * .outboundRelationship[typeCode=RSON or SUBJ].target
Events are reported by the actor that detected them. This may be one of the participating actors, but may also be different. The actor may be a human such as a medical-records clerk disclosing data manually, that clerk would be the source for the record of disclosure.
.participation[typeCode=INF].role[classCode=ASSIGN].player[classCode=DEV, determinerCode=INSTANCE]
Logical source location within the enterprise
Logical source location within the healthcare enterprise network. For example, a hospital or other provider location within a multi-entity provider group.
This value differentiates among the sites in a multi-site enterprise health information system.
The identity of source detecting the event
Identifier of the source where the event was detected.
This field ties the event to a specific source system. It may be used to group events for analysis according to where the event was detected.
The type of source where event originated
Code specifying the type of source where event originated.
This field indicates which type of source is identified by the Audit Source ID. It is an optional value that may be used to group events for analysis according to the type of source where the event occurred.
Code specifying the type of system that detected and recorded the event. Use of these codes is not required but is encouraged to maintain translation with DICOM AuditMessage schema.
Specific instances of data or objects that have been accessed.
Required unless the values for event identification, agent identification, and audit source identification are sufficient to document the entire auditable event. Because events may have more than one entity, this group can be a repeating set of values.
The event may have other entities involved.
.outboundRelationship[typeCode=SUBJ].target or .participation[typeCode=SBJ].role
Identifies a specific instance of the entity. The reference should be version specific. This is allowed to be a Parameters resource.
Use .what.display when all you have is a string (e.g. ParticipantObjectName).
ParticipantObjectTypeCode, ParticipantObjectName, ParticipantObjectID and ParticipantObjectIDTypeCode
Provenance.target, Provenance.entity.what
Code representing the role the entity played in the event being audited.
For some detailed audit analysis it may be necessary to indicate a more granular type of entity, based on the application role it serves.
role.code (not sure what this would mean for an Act)
Security labels for the identified entity.
This field identifies the security labels for a specific instance of an object, such as a patient, to detect/track privacy and security issues.
Example Security Labels from the Healthcare Privacy and Security Classification System.
The query parameters for a query-type entities.
The meaning and secondary-encoding of the content of base64 encoded blob is specific to the AuditEvent.type, AuditEvent.subtype, and AuditEvent.entity.role. The base64 is a general-use and safe container for event specific data blobs regardless of the encoding used by the transaction being recorded. An AuditEvent consuming application must understand the event it is consuming and the formats used by the event. For example, if auditing an Oracle network database access, the Oracle formats must be understood as they will be simply encoded in the base64binary blob. The DICOM AuditMessage schema does not support both .name and .query being populated.
For query events, it may be necessary to capture the actual query input to the query process in order to identify the specific event. Because of differences among query implementations and data encoding for them, this is a base 64 encoded data blob. It may be subsequently decoded or interpreted by downstream audit analysis processing.
Tagged value pairs for conveying additional information about the entity.
Implementation-defined data about specific details of the object accessed or used.
.inboundRelationship[typeCode=SUBJ].target[classCode=OBS, moodCode=EVN]
The type of extra detail provided in the value.
Additional detail about an entity used in an event.
Should not duplicate the entity value unless absolutely necessary.
The entity is attributed to an agent to express the agent's responsibility for that entity in the activity. This is most used to indicate when persistence media (the entity) are used by an agent. For example when importing data from a device, the device would be described in an entity, and the user importing data from that media would be indicated as the entity.agent.
A usecase where one AuditEvent.entity.agent is used where the Entity that was used in the creation/updating of a target resource, is not in the context of the same custodianship as the target resource, and thus the meaning of AuditEvent.entity.agent is to say that the entity referenced is managed elsewhere and that this Agent provided access to it. This would be similar to where the Entity being referenced is managed outside FHIR, such as through HL7 V2, v3, or XDS. This might be where the Entity being referenced is managed in another FHIR resource server. Thus it explains the provenance of that Entity's use in the context of this AuditEvent activity.
Extensions are always sliced by (at least) url
Literal reference, Relative, internal or absolute URL
A reference to a location at which the other resource is found. The reference may be a relative reference, in which case it is relative to the service base URL, or an absolute URL that resolves to the location where the resource is found. The reference may be version specific or not. If the reference is not to a FHIR RESTful server, then it should be assumed to be version specific. Internal fragment references (start with '#') refer to contained resources.
Using absolute URLs provides a stable scalable approach suitable for a cloud/web context, while using relative/logical references provides a flexible approach suitable for use when trading across closed eco-system boundaries. Absolute URLs do not need to point to a FHIR RESTful server, though this is the preferred approach. If the URL conforms to the structure "[type]/[id]" then it should be assumed that the reference is to a FHIR RESTful server.
Type the reference refers to (e.g. "Patient") - must be a resource in resources
The expected type of the target of the reference. If both Reference.type and Reference.reference are populated and Reference.reference is a FHIR URL, both SHALL be consistent. The type is the Canonical URL of Resource Definition that is the type this reference refers to. References are URLs that are relative to http://hl7.org/fhir/StructureDefinition/ e.g. "Patient" is a reference to http://hl7.org/fhir/StructureDefinition/Patient. Absolute URLs are only allowed for logical models (and can only be used in references in logical models, not resources).
This element is used to indicate the type of the target of the reference. This may be used which ever of the other elements are populated (or not). In some cases, the type of the target may be determined by inspection of the reference (e.g. a known RESTful URL) or by resolving the target of the reference.
Aa resource (or, for logical models, the URI of the logical model).
Logical reference, when literal reference is not known
An identifier for the target resource. This is used when there is no way to reference the other resource directly, either because the entity it represents is not available through a FHIR server, or because there is no way for the author of the resource to convert a known identifier to an actual location. There is no requirement that a Reference.identifier point to something that is actually exposed as a FHIR instance, but it SHALL point to a business concept that would be expected to be exposed as a FHIR instance, and that instance would need to be of a FHIR resource type allowed by the reference.
When an identifier is provided in place of a reference, any system processing the reference will only be able to resolve the identifier to a reference if it understands the business context in which the identifier is used. Sometimes this is global (e.g. a national identifier) but often it is not. For this reason, none of the useful mechanisms described for working with references (e.g. chaining, includes) are possible, nor should servers be expected to be able resolve the reference. Servers may accept an identifier based reference untouched, resolve it, and/or reject it - see CapabilityStatement.rest.resource.referencePolicy. When both an identifier and a literal reference are provided, the literal reference is preferred. Applications processing the resource are allowed - but not required - to check that the identifier matches the literal reference Applications converting a logical reference to a literal reference may choose to leave the logical reference present, or remove it. Reference is intended to point to a structure that can potentially be expressed as a FHIR resource, though there is no need for it to exist as an actual FHIR resource instance - except in as much as an application wishes to actual find the target of the reference. The content referred to be the identifier must meet the logical constraints implied by any limitations on what resource types are permitted for the reference. For example, it would not be legitimate to send the identifier for a drug prescription if the type were Reference(Observation|DiagnosticReport). One of the use-cases for Reference.identifier is the situation where no FHIR representation exists (where the type is Reference (Any). This element only allows for a single identifier. In the case where additional identifers are required, use the [http://hl7.org/fhir/StructureDefinition/additionalIdentifier](http://hl7.org/fhir/extensions/StructureDefinition-additionalIdentifier.html) extension.
usual | official | temp | secondary | old (If known)
Applications can assume that an identifier is permanent unless it explicitly says that it is temporary.
Allows the appropriate identifier for a particular context of use to be selected from among a set of identifiers.
This is labeled as "Is Modifier" because applications should not mistake a temporary id for a permanent one.
Identifies the purpose for this identifier, if known .
A coded type for the identifier that can be used to determine which identifier to use for a specific purpose.
This element deals only with general categories of identifiers. It SHOULD not be used for codes that correspond 1..1 with the Identifier.system. Some identifiers may fall into multiple categories due to common usage. Where the system is known, a type is unnecessary because the type is always part of the system definition. However systems often need to handle identifiers where the system is not known. There is not a 1:1 relationship between type and system, since many different systems have the same type.
Allows users to make use of identifiers when the identifier system is not known.
A coded type for an identifier that can be used to determine which identifier to use for a specific purpose.
Establishes the namespace for the value - that is, an absolute URL that describes a set values that are unique.
Identifier.system is always case sensitive.
There are many sets of identifiers. To perform matching of two identifiers, we need to know what set we're dealing with. The system identifies a particular set of unique identifiers.
The portion of the identifier typically relevant to the user and which is unique within the context of the system.
If the value is a full URI, then the system SHALL be urn:ietf:rfc:3986. The value's primary purpose is computational mapping. As a result, it may be normalized for comparison purposes (e.g. removing non-significant whitespace, dashes, etc.) A value formatted for human display can be conveyed using the [http://hl7.org/fhir/StructureDefinition/rendered-value](http://hl7.org/fhir/extensions/StructureDefinition-rendered-value.html)). Identifier.value is to be treated as case sensitive unless knowledge of the Identifier.system allows the processer to be confident that non-case-sensitive processing is safe.
II.extension or II.root if system indicates OID or GUID (Or Role.id.extension or root)
Time period when id is/was valid for use
Time period during which identifier is/was valid for use.
Role.effectiveTime or implied by context
Organization that issued id (may be just text)
Organization that issued/manages the identifier.
The Identifier.assigner may omit the .reference element and only contain a .display element reflecting the name or other textual information about the assigning organization.
II.assigningAuthorityName but note that this is an improper use by the definition of the field. Also Role.scoper
Plain text narrative that identifies the resource in addition to the resource reference.
This is generally not the same as the Resource.text of the referenced resource. The purpose is to identify what's being referenced, not to fully describe it.
may contain the security labels on the Bundle search set returned