A task to be performed.

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.

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.

An Extension

DSTU2: Order.when (new:BackboneElement)

Element Order.when has a context of Task based on following the parent source element upwards and mapping to Task. Element Order.when has no mapping targets in FHIR R5. Typically, this is because the element has been added (is a new element).

DSTU2: Order.detail (new:Reference(Resource))

Element Order.detail has a context of Task based on following the parent source element upwards and mapping to Task. Element Order.detail has no mapping targets in FHIR R5. Typically, this is because the element has been added (is a new element).

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).

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.

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.

The current status of the task.

The current status of the task.

These states enable coordination of task status with off-the-shelf workflow solutions that support automation of tasks.

Indicates the "level" of actionability associated with the Task, i.e. i+R[9]Cs this a proposed task, a planned task, an actionable task, etc.

This element is immutable. Proposed tasks, planned tasks, etc. must be distinct instances.

In most cases, Tasks will have an intent of "order".

Distinguishes whether the task is a proposal, plan or full order.

If true indicates that the Task is asking for the specified action to not occur.

The attributes provided with the Task qualify what is not to be done. For example, if a requestedPeriod is provided, the 'do not' request only applies within the specified time. If a requestedPerformer is specified then the 'do not' request only applies to performers of that type. Qualifiers include: code, subject, occurrence, requestedPerformer and performer.

In some cases, the Request.code may pre-coordinate prohibition into the requested action. E.g. 'NPO' (nothing by mouth), 'DNR' (do not recussitate). If this happens, doNotPerform SHALL NOT be set to true. I.e. The resource shall not have double negation. (E.g. 'Do not DNR').

doNotPerform should ONLY be used with Tasks that are tightly bounded in time or process phase. E.g. 'Do not fulfill the midnight dose of medication X tonight due to the early morning scheduled procedure, where the nurse could reasonably check off 'Med X not given at midnight as instructed'. Similarly, a decision support proposal that a patient should not be given a standard intake questionnaire (because the patient is cognitively impaired) would be marked as 'complete' or 'rejected' when the clinician preps the CarePlan or order set after reviewing the decision support results. If there is a need to create a standing order to not do something that can't be satisfied by a single 'non-action', but rather an ongoing refusal to perform the function, MedicationRequest, ServiceRequest or some other form of authorization should be used.

DSTU2: Order.meta additional types (Meta) additional types from child elements (lastUpdated, profile, security, tag, versionId)

Element Order.meta is mapped to FHIR R5 element Task.meta as SourceIsBroaderThanTarget. The mappings for Order.meta do not cover the following types: Meta. The mappings for Order.meta do not cover the following types based on type expansion: lastUpdated, profile, security, tag, versionId.

DSTU2: Order.text additional types (Narrative) additional types from child elements (div, status)

Element Order.text is mapped to FHIR R5 element Task.text as SourceIsBroaderThanTarget. The mappings for Order.text do not cover the following types: Narrative. The mappings for Order.text do not cover the following types based on type expansion: div, status. Contained resources do not have narrative. Resources that are not contained SHOULD have a narrative.

DSTU2: Order.when (new:BackboneElement)

Element Order.when has a context of Task based on following the parent source element upwards and mapping to Task. Element Order.when has no mapping targets in FHIR R5. Typically, this is because the element has been added (is a new element).

DSTU2: Order.detail (new:Reference(Resource))

Element Order.detail has a context of Task based on following the parent source element upwards and mapping to Task. Element Order.detail has no mapping targets in FHIR R5. Typically, this is because the element has been added (is a new element).

DSTU2: Order.identifier additional types (Identifier) additional types from child elements (assigner, period, system, type, use, value)

Element Order.identifier is mapped to FHIR R5 element Task.identifier as SourceIsBroaderThanTarget. The mappings for Order.identifier do not cover the following types: Identifier. The mappings for Order.identifier do not cover the following types based on type expansion: assigner, period, system, type, use, value.

DSTU2: Order.subject

Element Order.subject is mapped to FHIR R5 element Task.focus as SourceIsBroaderThanTarget. The standard extension alternate-reference has been mapped as the representation of FHIR DSTU2 element Order.subject with unmapped reference targets: Device, Group, Patient, Substance. May be left blank if the request reference identifies the patient, or if the request is not associated with a patient.

DSTU2: Order.source additional types from child elements (display, reference)

Element Order.source is mapped to FHIR R5 element Task.requester as RelatedTo. The mappings for Order.source do not cover the following types based on type expansion: display, reference. The standard extension alternate-reference has been mapped as the representation of FHIR DSTU2 element Order.source with unmapped reference targets: Organization, Practitioner.

DSTU2: Order.target

Element Order.target is mapped to FHIR R5 element Task.requester as RelatedTo. The standard extension alternate-reference has been mapped as the representation of FHIR DSTU2 element Order.target with unmapped reference targets: Device, Organization, Practitioner.

A task to be performed.

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.

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

An Extension

DSTU2: Order.meta additional types (Meta) additional types from child elements (lastUpdated, profile, security, tag, versionId)

Element Order.meta is mapped to FHIR R5 element Task.meta as SourceIsBroaderThanTarget. The mappings for Order.meta do not cover the following types: Meta. The mappings for Order.meta do not cover the following types based on type expansion: lastUpdated, profile, security, tag, versionId.

The version specific identifier, as it appears in the version portion of the URL. This value changes when the resource is created, updated, or deleted.

The server assigns this value, and ignores what the client specifies, except in the case that the server is imposing version integrity on updates/deletes.

When the resource last changed - e.g. when the version changed.

This element is generally omitted in instances submitted in a PUT or POST. Instead, it is populated in the response instance and when retrieving information using a GET. The server / resource manager sets this value; what a client provides is irrelevant. This is equivalent to the HTTP Last-Modified and SHOULD have the same value on a read interaction.

A uri that identifies the source system of the resource. This provides a minimal amount of Provenance information that can be used to track or differentiate the source of information in the resource. The source may identify another FHIR server, document, message, database, etc.

The exact use of the source (and the possible implied Provenance.entity.role and agent.role) is left to implementer discretion. Only one nominated source is allowed; for additional provenance details, a full Provenance resource should be used. The source may correspond to Provenance.entity.what[x] or Provenance.agent.who[x], though it may be a more general or abstract reference.

This element can be used to indicate where the current master source of a resource that has a canonical URL if the resource is no longer hosted at the canonical URL.

A list of profiles (references to StructureDefinition resources) that this resource claims to conform to. The URL is a reference to StructureDefinition.url.

It is up to the server and/or other infrastructure of policy to determine whether/how these claims are verified and/or updated over time. The list of profile URLs is a set.

Security labels applied to this resource. These tags connect specific resources to the overall security policy and infrastructure.

The security labels can be updated without changing the stated version of the resource. The list of security labels is a set. Uniqueness is based the system/code, and version and display are ignored.

Unless not suitable, these codes SHALL be taken from AllSecurityLabels
(extensible to http://hl7.org/fhir/ValueSet/security-labels|5.0.0)

Security Labels from the Healthcare Privacy and Security Classification System.

Tags applied to this resource. Tags are intended to be used to identify and relate resources to process and workflow, and applications are not required to consider the tags when interpreting the meaning of a resource.

The tags can be updated without changing the stated version of the resource. The list of tags is a set. Uniqueness is based the system/code, and version and display are ignored.

Codes that represent various types of tags, commonly workflow-related; e.g. "Needs review by Dr. Jones".

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.

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).

IETF language tag for a human language

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.

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

An Extension

DSTU2: Order.text additional types (Narrative) additional types from child elements (div, status)

Element Order.text is mapped to FHIR R5 element Task.text as SourceIsBroaderThanTarget. The mappings for Order.text do not cover the following types: Narrative. The mappings for Order.text do not cover the following types based on type expansion: div, status. Contained resources do not have narrative. Resources that are not contained SHOULD have a narrative.

The status of the narrative - whether it's entirely generated (from just the defined data or the extensions too), or whether a human authored it and it may contain additional data.

The status of a resource narrative.

The actual narrative content, a stripped down version of XHTML.

The contents of the html element are an XHTML fragment containing only the basic html formatting elements described in chapters 7-11 and 15 of the HTML 4.0 standard, <a> elements (either name or href), images and internally contained stylesheets. The XHTML content SHALL NOT contain a head, a body, external stylesheet references, scripts, forms, base/link/xlink, frames, iframes and objects.

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.

An Extension

DSTU2: Order.when (new:BackboneElement)

Element Order.when has a context of Task based on following the parent source element upwards and mapping to Task. Element Order.when has no mapping targets in FHIR R5. Typically, this is because the element has been added (is a new element).

DSTU2: Order.detail (new:Reference(Resource))

Element Order.detail has a context of Task based on following the parent source element upwards and mapping to Task. Element Order.detail has no mapping targets in FHIR R5. Typically, this is because the element has been added (is a new element).

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).

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.

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.

The business identifier for this task.

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

An Extension

DSTU2: Order.identifier additional types (Identifier) additional types from child elements (assigner, period, system, type, use, value)

Element Order.identifier is mapped to FHIR R5 element Task.identifier as SourceIsBroaderThanTarget. The mappings for Order.identifier do not cover the following types: Identifier. The mappings for Order.identifier do not cover the following types based on type expansion: assigner, period, system, type, use, value.

The purpose of this identifier.

Applications can assume that an identifier is permanent unless it explicitly says that it is temporary.

Identifies the purpose for this identifier, if known .

Allows the appropriate identifier for a particular context of use to be selected from among a set of identifiers.

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.

A coded type for an identifier that can be used to determine which identifier to use for a specific purpose.

Allows users to make use of identifiers when the identifier system is not known.

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). 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.

Time period during which identifier is/was valid for use.

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.

The URL pointing to a FHIR-defined protocol, guideline, orderset or other definition that is adhered to in whole or in part by this Task.

Enables a formal definition of how the task is to be performed, enabling automation.

The URL pointing to an externally maintained protocol, guideline, orderset or other definition that is adhered to in whole or in part by this Task.

Enables a formal definition of how the task is to be performed (e.g. using BPMN, BPEL, XPDL or other formal notation to be associated with a task), enabling automation.

BasedOn refers to a higher-level authorization that triggered the creation of the task. It references a "request" resource such as a ServiceRequest, MedicationRequest, CarePlan, etc. which is distinct from the "request" resource the task is seeking to fulfill. This latter resource is referenced by focus. For example, based on a CarePlan (= basedOn), a task is created to fulfill a ServiceRequest ( = focus ) to collect a specimen from a patient.

Task.basedOn is never the same as Task.focus. Task.basedOn will typically not be present for 'please fulfill' Tasks as a distinct authorization is rarely needed to request fulfillment. If the Task is seeking fulfillment of an order, the order to be fulfilled is always communicated using focus, never basedOn. However, authorization may be needed to perform other types of Task actions. As an example of when both would be present, a Task seeking suspension of a prescription might have a Task.basedOn pointing to the ServiceRequest ordering surgery (which is the driver for suspending the MedicationRequest - which would be the Task.focus).

A shared identifier common to multiple independent Task and Request instances that were activated/authorized more or less simultaneously by a single author. The presence of the same identifier on each request ties those requests together and may have business ramifications in terms of reporting of results, billing, etc. E.g. a requisition number shared by a set of lab tests ordered together, or a prescription number shared by all meds ordered at one time.

Billing and/or reporting can be linked to whether multiple requests were created as a single unit.

Task that this particular task is part of.

This should usually be 0..1.

Allows tasks to be broken down into sub-steps (and this division can occur independent of the original task).

The current status of the task.

The current status of the task.

These states enable coordination of task status with off-the-shelf workflow solutions that support automation of tasks.

An explanation as to why this task is held, failed, was refused, etc.

This applies to the current status. Look at the history of the task to see reasons for past statuses.

Codes to identify the reason for current status. These will typically be specific to a particular workflow.

Contains business-specific nuances of the business state.

The domain-specific business-contextual sub-state of the task. For example: "Blood drawn", "IV inserted", "Awaiting physician signature", etc.

There's often a need to track substates of a task - this is often variable by specific workflow implementation.

Indicates the "level" of actionability associated with the Task, i.e. i+R[9]Cs this a proposed task, a planned task, an actionable task, etc.

This element is immutable. Proposed tasks, planned tasks, etc. must be distinct instances.

In most cases, Tasks will have an intent of "order".

Distinguishes whether the task is a proposal, plan or full order.

Indicates how quickly the Task should be addressed with respect to other requests.

The priority of a task (may affect service level applied to the task).

Used to identify the service level expected while performing a task.

If true indicates that the Task is asking for the specified action to not occur.

The attributes provided with the Task qualify what is not to be done. For example, if a requestedPeriod is provided, the 'do not' request only applies within the specified time. If a requestedPerformer is specified then the 'do not' request only applies to performers of that type. Qualifiers include: code, subject, occurrence, requestedPerformer and performer.

In some cases, the Request.code may pre-coordinate prohibition into the requested action. E.g. 'NPO' (nothing by mouth), 'DNR' (do not recussitate). If this happens, doNotPerform SHALL NOT be set to true. I.e. The resource shall not have double negation. (E.g. 'Do not DNR').

doNotPerform should ONLY be used with Tasks that are tightly bounded in time or process phase. E.g. 'Do not fulfill the midnight dose of medication X tonight due to the early morning scheduled procedure, where the nurse could reasonably check off 'Med X not given at midnight as instructed'. Similarly, a decision support proposal that a patient should not be given a standard intake questionnaire (because the patient is cognitively impaired) would be marked as 'complete' or 'rejected' when the clinician preps the CarePlan or order set after reviewing the decision support results. If there is a need to create a standing order to not do something that can't be satisfied by a single 'non-action', but rather an ongoing refusal to perform the function, MedicationRequest, ServiceRequest or some other form of authorization should be used.

A name or code (or both) briefly describing what the task involves.

The title (eg "My Tasks", "Outstanding Tasks for Patient X") should go into the code.

Codes to identify what the task involves. These will typically be specific to a particular workflow.

A free-text description of what is to be performed.

The request being fulfilled or the resource being manipulated (changed, suspended, etc.) by this task.

If multiple resources need to be manipulated, use sub-tasks. (This ensures that status can be tracked independently for each referenced resource.).

Used to identify the thing to be done.

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

An Extension

DSTU2: Order.subject

Element Order.subject is mapped to FHIR R5 element Task.focus as SourceIsBroaderThanTarget. The standard extension alternate-reference has been mapped as the representation of FHIR DSTU2 element Order.subject with unmapped reference targets: Device, Group, Patient, Substance. May be left blank if the request reference identifies the patient, or if the request is not associated with a patient.

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.

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.

Unless not suitable, these codes SHALL be taken from ResourceType
(extensible to http://hl7.org/fhir/ValueSet/resource-types|5.0.0)

Aa resource (or, for logical models, the URI of the logical model).

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 extension.

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.

The entity who benefits from the performance of the service specified in the task (e.g., the patient).

Used to track tasks outstanding for a beneficiary. Do not use to track the task owner or creator (see owner and creator respectively). This can also affect access control.

The healthcare event (e.g. a patient and healthcare provider interaction) during which this task was created.

For some tasks it may be important to know the link between the encounter the task originated within.

Indicates the start and/or end of the period of time when completion of the task is desired to take place.

This is typically used when the Task is not seeking fulfillment of a focus Request, as in that case the period would be specified on the Request and/or in the Task.restriction.period. Instead, it is used for stand-alone tasks.

Identifies the time action was first taken against the task (start) and/or the time final action was taken against the task prior to marking it as completed (end).

The date and time this task was created.

Most often used along with lastUpdated to track duration of task to supporting monitoring and management.

The date and time of last modification to this task.

Used along with history to track task activity and time in a particular task state. This enables monitoring and management.

The creator of the task.

Identifies who created this task. May be used by access control mechanisms (e.g., to ensure that only the creator can cancel a task).

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

An Extension

DSTU2: Order.source additional types from child elements (display, reference)

Element Order.source is mapped to FHIR R5 element Task.requester as RelatedTo. The mappings for Order.source do not cover the following types based on type expansion: display, reference. The standard extension alternate-reference has been mapped as the representation of FHIR DSTU2 element Order.source with unmapped reference targets: Organization, Practitioner.

DSTU2: Order.target

Element Order.target is mapped to FHIR R5 element Task.requester as RelatedTo. The standard extension alternate-reference has been mapped as the representation of FHIR DSTU2 element Order.target with unmapped reference targets: Device, Organization, Practitioner.

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.

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.

Unless not suitable, these codes SHALL be taken from ResourceType
(extensible to http://hl7.org/fhir/ValueSet/resource-types|5.0.0)

Aa resource (or, for logical models, the URI of the logical model).

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 extension.

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.

The kind of participant or specific participant that should perform the task.

The type(s) of task performers allowed.

Use to distinguish tasks on different activity queues.

Party responsible for managing task execution.

Tasks may be created with an owner not yet identified.

Identifies who is expected to perform this task.

The entity who performed the requested task.

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.

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.

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).

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.

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.

A code or description of the performer of the task.

Codes to identify types of task performers.

The actor or entity who performed the task.

Principal physical location where this task is performed.

This should only be specified when the Task to be/being performed happens or is expected to happen primarily within the bounds of a single Location. Other locations (e.g. source, destination, etc.) would either be reflected on the 'basedOn' Request or be conveyed as distinct Task.input values.

Ties the event to where the records are likely kept and provides context around the event occurrence (e.g. if it occurred inside or outside a dedicated healthcare setting).

A description, code, or reference indicating why this task needs to be performed.

This will typically not be present for Tasks with a code of 'please fulfill' as, for those, the reason for action is conveyed on the Request pointed to by Task.focus. Some types of tasks will not need a 'reason'. E.g. a request to discharge a patient can be inferred to be 'because the patient is ready' and this would not need a reason to be stated on the Task.

Indicates why the task is needed. E.g. Suspended because patient admitted to hospital.

Insurance plans, coverage extensions, pre-authorizations and/or pre-determinations that may be relevant to the Task.

Free-text information captured about the task as it progresses.

Links to Provenance records for past versions of this Task that identify key state transitions or updates that are likely to be relevant to a user looking at the current version of the task.

This element does not point to the Provenance associated with the current version of the resource - as it would be created after this version existed. The Provenance for the current version can be retrieved with a _revinclude.

If the Task.focus is a request resource and the task is seeking fulfillment (i.e. is asking for the request to be actioned), this element identifies any limitations on what parts of the referenced request should be actioned.

Task.restriction can only be present if the Task is seeking fulfillment of another Request resource, and the restriction identifies what subset of the authorization conveyed by the request is supposed to be fulfilled by this Task. A possible example could be a standing order (the request) covering a significant time period and/or individuals, while the Task seeks fulfillment for only a subset of that time-period and a single individual.

Sometimes when fulfillment is sought, you don't want full fulfillment.

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.

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.

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).

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.

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.

Indicates the number of times the requested action should occur.

E.g. order that requests monthly lab tests, fulfillment is sought for 1.

The time-period for which fulfillment is sought. This must fall within the overall time period authorized in the referenced request. E.g. ServiceRequest.occurance[x].

This is distinct from Task.executionPeriod. ExecutionPeriod indicates when the task needs to be initiated, while Task.restriction.period specifies the subset of the overall authorization that this period covers. For example, a MedicationRequest with an overall effective period of 1 year might have a Task whose restriction.period is 2 months (i.e. satisfy 2 months of medication therapy), while the execution period might be 'between now and 5 days from now' - i.e. If you say yes to this, then you're agreeing to supply medication for that 2 month period within the next 5 days.

Note that period.high is the due date representing the time by which the task should be completed.

E.g. order that authorizes 1 year's services. Fulfillment is sought for next 3 months.

For requests that are targeted to more than one potential recipient/target, to identify who is fulfillment is sought for.

Additional information that may be needed in the execution of the task.

Resources and data used to perform the task. This data is used in the business logic of task execution, and is stored separately because it varies between workflows.

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.

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.

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).

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.

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.

A code or description indicating how the input is intended to be used as part of the task execution.

If referencing a BPMN workflow or Protocol, the "system" is the URL for the workflow definition and the code is the "name" of the required input.

Codes to identify types of input parameters. These will typically be specific to a particular workflow. E.g. "Comparison source", "Applicable consent", "Concomitent Medications", etc.

Inputs are named to enable task automation to bind data and pass it from one task to the next.

The value of the input parameter as a basic type.

Outputs produced by the Task.

Resources and data produced during the execution the task. This data is generated by the business logic of task execution, and is stored separately because it varies between workflows.

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.

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.

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).

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.

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.

The name of the Output parameter.

Codes to identify types of input parameters. These will typically be specific to a particular workflow. E.g. "Identified issues", "Preliminary results", "Filler order", "Final results", etc.

Outputs are named to enable task automation to bind data and pass it from one task to the next.

The value of the Output parameter as a basic type.

Task outputs can take any form.