A clinical condition, problem, diagnosis, or other event, situation, issue, or clinical concept that has risen to a level of concern.

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.

Human readable specification of the problem. This is a general notes/comments entry for description of the problem, its diagnosis and prognosis.

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.

An Extension

When the asserter identified the allergy, intolerance, condition, problem, or diagnosis or other event, situation, issue, or clinical concept that may have risen to a level of or remains a concern. For example, when the patient experiences chest pain, the asserted date represents when the clinician began following the chest pain - not when the patient experienced the chest pain. Asserted date supports the recognition that information is not always entered in a system immediately. Assertion and recording are different acts, so asserted date and recorded date are semantically different. However, they may be the same date and close in time. If this difference is significant for your use case, assertion date may be useful.

The assertedDate is in the context of the recording practitioner and might not be the same as the recordedDate.

An Extension

Source of the definition for the extension code - a logical name or a URL.

The definition may point directly to a computable or human-readable definition of the extensibility codes, or it may be a logical URI as declared in some other specification. The definition SHALL be a URI for the Structure Definition defining the extension.

Value of extension - must be one of a constrained set of the data types (see Extensibility for a list).

Related artifacts such as additional documentation, justification, dependencies, bibliographic references, and predecessor and successor artifacts.

Each related artifact is either an attachment, or a reference to another resource, but 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).

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.

Globally unique identifier of this problem which remain constant as the resource is updated and propagates from server to server.

This is a business identifier, not a resource identifier (see discussion). It is best practice for the identifier to only appear on a single resource instance, however business practices may occasionally dictate that multiple resource instances with the same identifier can exist - possibly even with different resource types. For example, multiple Patient and a Person resource instance might share the same social insurance number.

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

The problem status describes the condition of the problem:

1. Active problems are problems of which the patient experiences symptoms or for which evidence exists.

2. If condition is abated, then clinicalStatus must be either inactive, resolved, or remission.

3. Problems with the status 'Inactive' refer to problems that don't affect the patient anymore or that of which there is no evidence of existence anymore.

The data type is CodeableConcept because clinicalStatus has some clinical judgment involved, such that there might need to be more specificity than the required FHIR value set allows. For example, a SNOMED coding might allow for additional specificity. clinicalStatus is required since it is a modifier element. For conditions that are problems list items, the clinicalStatus should not be unknown. For conditions that are not problem list items, the clinicalStatus may be unknown. For example, conditions derived from a claim are point in time, so those conditions may have a clinicalStatus of unknown

The verification status to support the clinical status of the condition.

verificationStatus is not required. For example, when a patient has abdominal pain in the ED, there is not likely going to be a verification status. The data type is CodeableConcept because verificationStatus has some clinical judgment involved, such that there might need to be more specificity than the required FHIR value set allows. For example, a SNOMED coding might allow for additional specificity.

A category assigned to the condition.

The categorization is often highly contextual and may appear poorly differentiated or not very useful in other contexts.

A category assigned to the condition.

A subjective assessment of the severity of the condition as evaluated by the clinician.

Coding of the severity with a terminology is preferred, where possible.

The problem code specifies the problem. Depending on the setting, different code systems can be used. The ProblemCodelist provides an overview of the possible code systems.

The codes SHOULD be taken from For example codes, see Problems - IPS http://hl7.org/fhir/ValueSet/condition-code|5.0.0
(preferred to http://hl7.org/fhir/uv/ips/ValueSet/problems-uv-ips)

Valueset to describe the actual problem experienced by the patient

Additional Bindings	Purpose	Documentation
eHDSI Illness and Disorder	candidate	Additional conformance binding to a problem code when ICD-10 or Orphanet codes are used.

0..1 to account for primarily narrative only resources.

The anatomical location where this condition manifests itself.

Only used if not implicit in code found in Condition.code. If the use case requires attributes from the BodyStructure resource (e.g. to identify and track separately) then use the standard extension http://hl7.org/fhir/StructureDefinition/bodySite. May be a summary code, or a reference to a very precise definition of the location, or both.

Record details about the anatomical location of a specimen or body part. This resource may be used when a coded concept does not provide the necessary detail needed for the use case.

An Extension

Source of the definition for the extension code - a logical name or a URL.

The definition may point directly to a computable or human-readable definition of the extensibility codes, or it may be a logical URI as declared in some other specification. The definition SHALL be a URI for the Structure Definition defining the extension.

Value of extension - must be one of a constrained set of the data types (see Extensibility for a list).

Indicates the patient or group who the condition record is associated with.

Group is typically used for veterinary or public health use cases.

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.

Estimated or actual date or date-time the condition began, in the opinion of the clinician.

Age is generally used when the patient reports an age at which the Condition began to occur. Period is generally used to convey an imprecise onset that occurred within the time period. For example, Period is not intended to convey the transition period before the chronic bronchitis or COPD condition was diagnosed, but Period can be used to convey an imprecise diagnosis date. Range is generally used to convey an imprecise age range (e.g. 4 to 6 years old). Because a Condition.code can represent multiple levels of granularity and can be modified over time, the onset and abatement dates can have ambiguity whether those dates apply to the current Condition.code or an earlier representation of that Condition.code. For example, if the Condition.code was initially documented as severe asthma, then it is ambiguous whether the onset and abatement dates apply to asthma (overall in that subject's lifetime) or when asthma transitioned to become severe.

Onset of the symptom, complaint, functional limitation, complication or date of diagnosis. A ‘vague’ date, such as only the year or the month and the year, is permitted.

Age is generally used when the patient reports an age at which the Condition began to occur. Period is generally used to convey an imprecise onset that occurred within the time period. For example, Period is not intended to convey the transition period before the chronic bronchitis or COPD condition was diagnosed, but Period can be used to convey an imprecise diagnosis date. Range is generally used to convey an imprecise age range (e.g. 4 to 6 years old). Because a Condition.code can represent multiple levels of granularity and can be modified over time, the onset and abatement dates can have ambiguity whether those dates apply to the current Condition.code or an earlier representation of that Condition.code. For example, if the Condition.code was initially documented as severe asthma, then it is ambiguous whether the onset and abatement dates apply to asthma (overall in that subject's lifetime) or when asthma transitioned to become severe.

The date or estimated date that the condition resolved or went into remission. This is called "abatement" because of the many overloaded connotations associated with "remission" or "resolution" - Some conditions, such as chronic conditions, are never really resolved, but they can abate.

There is no explicit distinction between resolution and remission because in many cases the distinction is not clear. Age is generally used when the patient reports an age at which the Condition abated. If there is no abatement element, it is unknown whether the condition has resolved or entered remission; applications and users should generally assume that the condition is still valid. When abatementString exists, it implies the condition is abated. Because a Condition.code can represent multiple levels of granularity and can be modified over time, the onset and abatement dates can have ambiguity whether those dates apply to the current Condition.code or an earlier representation of that Condition.code. For example, if the Condition.code was initially documented as severe asthma, then it is ambiguous whether the onset and abatement dates apply to asthma (overall in that subject's lifetime) or when asthma transitioned to become severe.

The date or estimated date that the condition resolved or went into remission. A ‘vague’ date, such as only the year or the month and the year, is permitted

There is no explicit distinction between resolution and remission because in many cases the distinction is not clear. Age is generally used when the patient reports an age at which the Condition abated. If there is no abatement element, it is unknown whether the condition has resolved or entered remission; applications and users should generally assume that the condition is still valid. When abatementString exists, it implies the condition is abated. Because a Condition.code can represent multiple levels of granularity and can be modified over time, the onset and abatement dates can have ambiguity whether those dates apply to the current Condition.code or an earlier representation of that Condition.code. For example, if the Condition.code was initially documented as severe asthma, then it is ambiguous whether the onset and abatement dates apply to asthma (overall in that subject's lifetime) or when asthma transitioned to become severe.

The recordedDate represents when this particular Condition record was created in the system, which is often a system-generated date.

When onset date is unknown, recordedDate can be used to establish if the condition was present on or before a given date. If the recordedDate is known and provided by a sending system, it is preferred that the receiving system preserve that recordedDate value. If the recordedDate is not provided by the sending system, the receipt timestamp is sometimes used as the recordedDate.

A simple summary of the stage such as "Stage 3" or "Early Onset". The determination of the stage is disease-specific, such as cancer, retinopathy of prematurity, kidney diseases, Alzheimer's, or Parkinson disease.

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 simple summary of the stage such as "Stage 3" or "Early Onset". The determination of the stage is disease-specific, such as cancer, retinopathy of prematurity, kidney diseases, Alzheimer's, or Parkinson disease.

Codes describing condition stages (e.g. Cancer stages).

Reference to the evidence on which the staging assessment is based.

The kind of staging, such as pathological or clinical staging.

Codes describing the kind of condition staging (e.g. clinical or pathological).

Comment by the one who determined or updated the Problem.

Human readable specification of the problem. This is a general notes/comments entry for description of the problem, its diagnosis and prognosis.

Globally unique identifier of this problem which remain constant as the resource is updated and propagates from server to server.

The problem status describes the condition of the problem:

1. Active problems are problems of which the patient experiences symptoms or for which evidence exists.

2. If condition is abated, then clinicalStatus must be either inactive, resolved, or remission.

3. Problems with the status 'Inactive' refer to problems that don't affect the patient anymore or that of which there is no evidence of existence anymore.

The verification status to support the clinical status of the condition.

The problem code specifies the problem. Depending on the setting, different code systems can be used. The ProblemCodelist provides an overview of the possible code systems.

The codes SHOULD be taken from Problems - IPS
(preferred to http://hl7.org/fhir/uv/ips/ValueSet/problems-uv-ips)

Valueset to describe the actual problem experienced by the patient

Additional Bindings	Purpose	Documentation
eHDSI Illness and Disorder	candidate	Additional conformance binding to a problem code when ICD-10 or Orphanet codes are used.

Onset of the symptom, complaint, functional limitation, complication or date of diagnosis. A ‘vague’ date, such as only the year or the month and the year, is permitted.

The date or estimated date that the condition resolved or went into remission. A ‘vague’ date, such as only the year or the month and the year, is permitted

Reference to the evidence on which the staging assessment is based.

Comment by the one who determined or updated the Problem.

A clinical condition, problem, diagnosis, or other event, situation, issue, or clinical concept that has risen to a level of concern.

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.

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

Human readable specification of the problem. This is a general notes/comments entry for description of the problem, its diagnosis and prognosis.

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.

An Extension

When the asserter identified the allergy, intolerance, condition, problem, or diagnosis or other event, situation, issue, or clinical concept that may have risen to a level of or remains a concern. For example, when the patient experiences chest pain, the asserted date represents when the clinician began following the chest pain - not when the patient experienced the chest pain. Asserted date supports the recognition that information is not always entered in a system immediately. Assertion and recording are different acts, so asserted date and recorded date are semantically different. However, they may be the same date and close in time. If this difference is significant for your use case, assertion date may be useful.

The assertedDate is in the context of the recording practitioner and might not be the same as the recordedDate.

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

An Extension

Source of the definition for the extension code - a logical name or a URL.

The definition may point directly to a computable or human-readable definition of the extensibility codes, or it may be a logical URI as declared in some other specification. The definition SHALL be a URI for the Structure Definition defining the extension.

Value of extension - must be one of a constrained set of the data types (see Extensibility for a list).

Related artifacts such as additional documentation, justification, dependencies, bibliographic references, and predecessor and successor artifacts.

Each related artifact is either an attachment, or a reference to another resource, but 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).

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.

Globally unique identifier of this problem which remain constant as the resource is updated and propagates from server to server.

This is a business identifier, not a resource identifier (see discussion). It is best practice for the identifier to only appear on a single resource instance, however business practices may occasionally dictate that multiple resource instances with the same identifier can exist - possibly even with different resource types. For example, multiple Patient and a Person resource instance might share the same social insurance number.

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

The problem status describes the condition of the problem:

1. Active problems are problems of which the patient experiences symptoms or for which evidence exists.

2. If condition is abated, then clinicalStatus must be either inactive, resolved, or remission.

3. Problems with the status 'Inactive' refer to problems that don't affect the patient anymore or that of which there is no evidence of existence anymore.

The data type is CodeableConcept because clinicalStatus has some clinical judgment involved, such that there might need to be more specificity than the required FHIR value set allows. For example, a SNOMED coding might allow for additional specificity. clinicalStatus is required since it is a modifier element. For conditions that are problems list items, the clinicalStatus should not be unknown. For conditions that are not problem list items, the clinicalStatus may be unknown. For example, conditions derived from a claim are point in time, so those conditions may have a clinicalStatus of unknown

The verification status to support the clinical status of the condition.

verificationStatus is not required. For example, when a patient has abdominal pain in the ED, there is not likely going to be a verification status. The data type is CodeableConcept because verificationStatus has some clinical judgment involved, such that there might need to be more specificity than the required FHIR value set allows. For example, a SNOMED coding might allow for additional specificity.

A category assigned to the condition.

The categorization is often highly contextual and may appear poorly differentiated or not very useful in other contexts.

A category assigned to the condition.

A subjective assessment of the severity of the condition as evaluated by the clinician.

Coding of the severity with a terminology is preferred, where possible.

The problem code specifies the problem. Depending on the setting, different code systems can be used. The ProblemCodelist provides an overview of the possible code systems.

The codes SHOULD be taken from Problems - IPS
(preferred to http://hl7.org/fhir/uv/ips/ValueSet/problems-uv-ips)

Valueset to describe the actual problem experienced by the patient

Additional Bindings	Purpose	Documentation
eHDSI Illness and Disorder	candidate	Additional conformance binding to a problem code when ICD-10 or Orphanet codes are used.

0..1 to account for primarily narrative only resources.

The anatomical location where this condition manifests itself.

Only used if not implicit in code found in Condition.code. If the use case requires attributes from the BodyStructure resource (e.g. to identify and track separately) then use the standard extension http://hl7.org/fhir/StructureDefinition/bodySite. May be a summary code, or a reference to a very precise definition of the location, or both.

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.

Record details about the anatomical location of a specimen or body part. This resource may be used when a coded concept does not provide the necessary detail needed for the use case.

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

An Extension

Source of the definition for the extension code - a logical name or a URL.

The definition may point directly to a computable or human-readable definition of the extensibility codes, or it may be a logical URI as declared in some other specification. The definition SHALL be a URI for the Structure Definition defining the extension.

Value of extension - must be one of a constrained set of the data types (see Extensibility for a list).

A reference to a code defined by a terminology system.

Codes may be defined very casually in enumerations, or code lists, up to very formal definitions such as SNOMED CT - see the HL7 v3 Core Principles for more information. Ordering of codings is undefined and SHALL NOT be used to infer meaning. Generally, at most only one of the coding values will be labeled as UserSelected = true.

Allows for alternative encodings within a code system, and translations to other code systems.

A human language representation of the concept as seen/selected/uttered by the user who entered the data and/or which represents the intended meaning of the user.

Very often the text is the same as a displayName of one of the codings.

The codes from the terminologies do not always capture the correct meaning with all the nuances of the human using them, or sometimes there is no appropriate code at all. In these cases, the text is used to capture the full meaning of the source.

Indicates the patient or group who the condition record is associated with.

Group is typically used for veterinary or public health use cases.

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.

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.

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 Encounter during which this Condition was created or to which the creation of this record is tightly associated.

This will typically be the encounter the event occurred within, but some activities may be initiated prior to or after the official completion of an encounter but still be tied to the context of the encounter. This record indicates the encounter this particular record is associated with. In the case of a "new" diagnosis reflecting ongoing/revised information about the condition, this might be distinct from the first encounter in which the underlying condition was first "known".

Estimated or actual date or date-time the condition began, in the opinion of the clinician.

Age is generally used when the patient reports an age at which the Condition began to occur. Period is generally used to convey an imprecise onset that occurred within the time period. For example, Period is not intended to convey the transition period before the chronic bronchitis or COPD condition was diagnosed, but Period can be used to convey an imprecise diagnosis date. Range is generally used to convey an imprecise age range (e.g. 4 to 6 years old). Because a Condition.code can represent multiple levels of granularity and can be modified over time, the onset and abatement dates can have ambiguity whether those dates apply to the current Condition.code or an earlier representation of that Condition.code. For example, if the Condition.code was initially documented as severe asthma, then it is ambiguous whether the onset and abatement dates apply to asthma (overall in that subject's lifetime) or when asthma transitioned to become severe.

Onset of the symptom, complaint, functional limitation, complication or date of diagnosis. A ‘vague’ date, such as only the year or the month and the year, is permitted.

Age is generally used when the patient reports an age at which the Condition began to occur. Period is generally used to convey an imprecise onset that occurred within the time period. For example, Period is not intended to convey the transition period before the chronic bronchitis or COPD condition was diagnosed, but Period can be used to convey an imprecise diagnosis date. Range is generally used to convey an imprecise age range (e.g. 4 to 6 years old). Because a Condition.code can represent multiple levels of granularity and can be modified over time, the onset and abatement dates can have ambiguity whether those dates apply to the current Condition.code or an earlier representation of that Condition.code. For example, if the Condition.code was initially documented as severe asthma, then it is ambiguous whether the onset and abatement dates apply to asthma (overall in that subject's lifetime) or when asthma transitioned to become severe.

The date or estimated date that the condition resolved or went into remission. This is called "abatement" because of the many overloaded connotations associated with "remission" or "resolution" - Some conditions, such as chronic conditions, are never really resolved, but they can abate.

There is no explicit distinction between resolution and remission because in many cases the distinction is not clear. Age is generally used when the patient reports an age at which the Condition abated. If there is no abatement element, it is unknown whether the condition has resolved or entered remission; applications and users should generally assume that the condition is still valid. When abatementString exists, it implies the condition is abated. Because a Condition.code can represent multiple levels of granularity and can be modified over time, the onset and abatement dates can have ambiguity whether those dates apply to the current Condition.code or an earlier representation of that Condition.code. For example, if the Condition.code was initially documented as severe asthma, then it is ambiguous whether the onset and abatement dates apply to asthma (overall in that subject's lifetime) or when asthma transitioned to become severe.

The date or estimated date that the condition resolved or went into remission. A ‘vague’ date, such as only the year or the month and the year, is permitted

There is no explicit distinction between resolution and remission because in many cases the distinction is not clear. Age is generally used when the patient reports an age at which the Condition abated. If there is no abatement element, it is unknown whether the condition has resolved or entered remission; applications and users should generally assume that the condition is still valid. When abatementString exists, it implies the condition is abated. Because a Condition.code can represent multiple levels of granularity and can be modified over time, the onset and abatement dates can have ambiguity whether those dates apply to the current Condition.code or an earlier representation of that Condition.code. For example, if the Condition.code was initially documented as severe asthma, then it is ambiguous whether the onset and abatement dates apply to asthma (overall in that subject's lifetime) or when asthma transitioned to become severe.

The recordedDate represents when this particular Condition record was created in the system, which is often a system-generated date.

When onset date is unknown, recordedDate can be used to establish if the condition was present on or before a given date. If the recordedDate is known and provided by a sending system, it is preferred that the receiving system preserve that recordedDate value. If the recordedDate is not provided by the sending system, the receipt timestamp is sometimes used as the recordedDate.

Indicates who or what participated in the activities related to the condition and how they were involved.

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.

Distinguishes the type of involvement of the actor in the activities related to the condition.

Indicates who or what participated in the activities related to the condition.

A simple summary of the stage such as "Stage 3" or "Early Onset". The determination of the stage is disease-specific, such as cancer, retinopathy of prematurity, kidney diseases, Alzheimer's, or Parkinson disease.

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 simple summary of the stage such as "Stage 3" or "Early Onset". The determination of the stage is disease-specific, such as cancer, retinopathy of prematurity, kidney diseases, Alzheimer's, or Parkinson disease.

Codes describing condition stages (e.g. Cancer stages).

Reference to the evidence on which the staging assessment is based.

The kind of staging, such as pathological or clinical staging.

Codes describing the kind of condition staging (e.g. clinical or pathological).

Supporting evidence / manifestations that are the basis of the Condition's verification status, such as evidence that confirmed or refuted the condition.

If the condition was confirmed, but subsequently refuted, then the evidence can be cumulative including all evidence over time. The evidence may be a simple list of coded symptoms/manifestations, or references to observations or formal assessments, or both. For example, if the Condition.code is pneumonia, then there could be an evidence list where Condition.evidence.concept = fever (CodeableConcept), Condition.evidence.concept = cough (CodeableConcept), and Condition.evidence.reference = bronchitis (reference to Condition).

Comment by the one who determined or updated the Problem.