Interweave Implementation Guide
0.1.0 - ci-build

Interweave Implementation Guide - Local Development build (v0.1.0) built by the FHIR (HL7® FHIR® Standard) Build Tools. See the R4 profiles here.

Resource Profile: InterweaveObservationWeight - Detailed Descriptions

Active as of 2024-07-17

Definitions for the Interweave-Observation-Weight resource profile.

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

1. Observation
2. Observation.extension:reason
SliceNamereason
Control0..0*
3. Observation.extension:valuePrecision
SliceNamevaluePrecision
Control0..01
4. Observation.status
Fixed Valuefinal
5. Observation.category
Control1..1*
6. Observation.category.coding:snomedCT
SliceNamesnomedCT
Control0..01
7. Observation.category:observationCategory
SliceNameobservationCategory
8. Observation.category:observationCategory.coding
9. Observation.category:observationCategory.coding.code
Fixed Valuevital-signs
10. Observation.category:observationCategory.coding.display
Fixed ValueVital Signs
11. Observation.code
BindingThe codes SHOULD be taken from Vital SignsThe codes SHOULD be taken from Care Connect Observation Type
12. Observation.code.coding
Control10..*
13. Observation.code.coding:snomedCT
SliceNamesnomedCT
14. Observation.code.coding:snomedCT.code
Fixed Value27113001
15. Observation.code.coding:snomedCT.display
Fixed ValueBody weight
16. Observation.code.coding:loinc
SliceNameloinc
Control1..1
17. Observation.code.coding:loinc.system
Control0..?
Fixed Valuehttp://loinc.org
18. Observation.code.coding:loinc.code
Control0..?
Fixed Value29463-7
19. Observation.code.coding:loinc.display
Control0..?
Fixed ValueBody weight
20. Observation.effective[x]
TypeChoice of: , Period
[x] NoteSee Choice of Data Types for further information about how to use [x]
21. Observation.value[x]
Control10..1
TypeChoice of: , dateTime, boolean, string, SampledData, Period, Ratio, time, Range, CodeableConcept
[x] NoteSee Choice of Data Types for further information about how to use [x]
22. Observation.dataAbsentReason
Control0..01
23. Observation.interpretation
Control0..01
24. Observation.bodySite
Control0..01
25. Observation.specimen
Control0..01
26. Observation.referenceRange
Control0..0*
27. Observation.component
Control0..0*

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

1. Observation
Definition

Measurements and simple assertions made about a patient, device or other subject.

Control0..*
Alternate NamesVital Signs, Measurement, Results, Tests
Comments

Used for simple observations such as device measurements, laboratory atomic results, vital signs, height, weight, smoking status, comments, etc. Other resources are used to provide context for observations such as lab reports, etc.

InvariantsDefined on this element
dom-1: If the resource is contained in another resource, it SHALL NOT contain any narrative (: contained.text.empty())
dom-2: If the resource is contained in another resource, it SHALL NOT contain nested Resources (: contained.contained.empty())
dom-3: If the resource is contained in another resource, it SHALL be referred to from elsewhere in the resource (: contained.where(('#'+id in %resource.descendants().reference).not()).empty())
dom-4: If a resource is contained in another resource, it SHALL NOT have a meta.versionId or a meta.lastUpdated (: contained.meta.versionId.empty() and contained.meta.lastUpdated.empty())
obs-6: dataAbsentReason SHALL only be present if Observation.value[x] is not present (: dataAbsentReason.empty() or value.empty())
obs-7: If code is the same as a component code then the value element associated with the code SHALL NOT be present (: value.empty() or component.code.where( (coding.code = %resource.code.coding.code) and (coding.system = %resource.code.coding.system)).empty())
2. Observation.id
Definition

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

Control0..1
Typeid
Must Supporttrue
Summarytrue
Comments

The only time that a resource does not have an id is when it is being submitted to the server using a create operation.

3. Observation.meta
Definition

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

Control0..1
TypeMeta
Summarytrue
4. Observation.meta.versionId
Definition

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

Control0..1
Typeid
Must Supporttrue
Summarytrue
Comments

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.

5. Observation.meta.lastUpdated
Definition

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

Control0..1
Typeinstant
Must Supporttrue
Summarytrue
Comments

This value is always populated except when the resource is first being created. The server / resource manager sets this value; what a client provides is irrelevant.

6. Observation.meta.profile
Definition

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

Control0..*
Typeuri
Must Supporttrue
Summarytrue
Comments

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.

7. Observation.meta.tag
Definition

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.

Control0..*
BindingFor example codes, see Common Tags

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

TypeCoding
Summarytrue
Comments

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.

SlicingThis element introduces a set of slices on Observation.meta.tag. The slices are unordered and Open, and can be differentiated using the following discriminators:
  • value @ system
8. Observation.meta.tag:Source
SliceNameSource
Definition

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.

Control0..1*
BindingFor example codes, see Common Tags

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

TypeCoding
Must Supporttrue
Summarytrue
Comments

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.

9. Observation.meta.tag:Source.system
Definition

The identification of the code system that defines the meaning of the symbol in the code.

Control10..1
Typeuri
Summarytrue
Requirements

Need to be unambiguous about the source of the definition of the symbol.

Comments

The URI may be an OID (urn:oid:...) or a UUID (urn:uuid:...). OIDs and UUIDs SHALL be references to the HL7 OID registry. Otherwise, the URI should come from HL7's list of FHIR defined special URIs or it should de-reference to some definition that establish the system clearly and unambiguously.

Fixed Valuehttps://yhcr.nhs.uk/Source
10. Observation.meta.tag:Source.code
Definition

A symbol in syntax defined by the system. The symbol may be a predefined code or an expression in a syntax defined by the coding system (e.g. post-coordination).

Control10..1
Typecode
Must Supporttrue
Summarytrue
Requirements

Need to refer to a particular code in the system.

11. Observation.meta.tag:Source.display
Definition

A representation of the meaning of the code in the system, following the rules of the system.

Control10..1
Typestring
Must Supporttrue
Summarytrue
Requirements

Need to be able to carry a human-readable meaning of the code for readers that do not know the system.

12. Observation.meta.tag:Provenance
SliceNameProvenance
Definition

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.

Control0..1*
BindingFor example codes, see Common Tags

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

TypeCoding
Must Supporttrue
Summarytrue
Comments

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.

13. Observation.meta.tag:Provenance.system
Definition

The identification of the code system that defines the meaning of the symbol in the code.

Control10..1
Typeuri
Summarytrue
Requirements

Need to be unambiguous about the source of the definition of the symbol.

Comments

The URI may be an OID (urn:oid:...) or a UUID (urn:uuid:...). OIDs and UUIDs SHALL be references to the HL7 OID registry. Otherwise, the URI should come from HL7's list of FHIR defined special URIs or it should de-reference to some definition that establish the system clearly and unambiguously.

Fixed Valuehttps://yhcr.nhs.uk/Provenance
14. Observation.meta.tag:Provenance.code
Definition

A symbol in syntax defined by the system. The symbol may be a predefined code or an expression in a syntax defined by the coding system (e.g. post-coordination).

Control10..1
Typecode
Must Supporttrue
Summarytrue
Requirements

Need to refer to a particular code in the system.

15. Observation.meta.tag:Provenance.display
Definition

A representation of the meaning of the code in the system, following the rules of the system.

Control10..1
Typestring
Must Supporttrue
Summarytrue
Requirements

Need to be able to carry a human-readable meaning of the code for readers that do not know the system.

16. Observation.implicitRules
Definition

A reference to a set of rules that were followed when the resource was constructed, and which must be understood when processing the content.

Control0..1
Typeuri
Is Modifiertrue
Summarytrue
Comments

Asserting this rule set restricts the content to be only understood by a limited set of trading partners. This inherently limits the usefulness of the data in the long term. However, the existing health eco-system is highly fractured, and not yet ready to define, collect, and exchange data in a generally computable sense. Wherever possible, implementers and/or specification writers should avoid using this element.

This element is labelled as a modifier because the implicit rules may provide additional knowledge about the resource that modifies it's meaning or interpretation.

17. Observation.extension:reason
SliceNamereason
Definition

Reason resource added/performed/given.

Control0..0 This element is affected by the following invariants: ele-1
TypeExtension(Extension-CareConnect-ReasonCondition-1) (Extension Type: Choice of: CodeableConcept, Reference(CareConnect-Condition-1))
InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() | (children().count() > id.count()))
ext-1: Must have either extensions or value[x], not both (: extension.exists() != value.exists())
18. Observation.extension:valuePrecision
SliceNamevaluePrecision
Definition

Explicit precision of the number. This is the number of significant decimal places after the decimal point, irrespective of how many are actually present in the explicitly represented decimal.

Control0..0
TypeExtension(ExtensionInterweaveValuePrecision) (Extension Type: integer)
Comments

The presence of this extension does not change conformance expectations with regard to rendering and calculations that use the number - these are still based on the raw decimal value. Applications that perform calculations SHALL ensure that this extension is removed or updated to the correct precision value if the number is changed. Applications should consider using the exponential form (e.g. 2.10e3) on the raw decimal to manage significant figures, but should be mindful of human display when doing so.

19. Observation.modifierExtension
Definition

May be used to represent additional information that is not part of the basic definition of the resource, and that modifies the understanding of the element that contains it. Usually modifier elements provide negation or qualification. In order to make the use of extensions safe and manageable, 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.

Control0..*
TypeExtension
Is Modifiertrue
Alternate Namesextensions, user content
Comments

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

20. Observation.identifier
Definition

A unique identifier assigned to this observation.

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

Allows observations to be distinguished and referenced.

21. Observation.identifier.use
Definition

The purpose of this identifier.

Control0..1
BindingThe codes SHALL be taken from IdentifierUse

Identifies the purpose for this identifier, if known .

Typecode
Is Modifiertrue
Summarytrue
Requirements

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

Comments

This is labeled as "Is Modifier" because applications should not mistake a temporary id for a permanent one. Applications can assume that an identifier is permanent unless it explicitly says that it is temporary.

22. Observation.identifier.system
Definition

Establishes the namespace for the value - that is, a URL that describes a set values that are unique.

Control10..1
Typeuri
Summarytrue
Requirements

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.

Example
General:http://www.acme.com/identifiers/patient
23. Observation.identifier.value
Definition

The portion of the identifier typically relevant to the user and which is unique within the context of the system.

Control10..1
Typestring
Summarytrue
Comments

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 Rendered Value extension.

Example
General:123456
24. Observation.status
Definition

The status of the result value.

Control1..1
BindingThe codes SHALL be taken from ObservationStatus
Typecode
Is Modifiertrue
Must Supporttrue
Summarytrue
Requirements

Need to track the status of individual results. Some results are finalized before the whole report is finalized.

Comments

This element is labeled as a modifier because the status contains codes that mark the resource as not currently valid.

Fixed Valuefinal
25. Observation.category
Definition

A code that classifies the general type of observation being made.

Control10..1*
BindingThe codes SHOULD be taken from Observation Category Codes

Codes for high level observation categories.

TypeCodeableConcept
Must Supporttrue
Requirements

Used for filtering what observations are retrieved and displayed.

Comments

In addition to the required category valueset, this element allows various categorization schemes based on the owner’s definition of the category and effectively multiple categories can be used at once. The level of granularity is defined by the category concepts in the value set.

SlicingThis element introduces a set of slices on Observation.category. The slices are unordered and Open, and can be differentiated using the following discriminators:
  • value @ coding.system
26. Observation.category.coding
Definition

A reference to a code defined by a terminology system.

Control0..*
TypeCoding
Summarytrue
Requirements

Allows for translations and alternate encodings within a code system. Also supports communication of the same instance to systems requiring different encodings.

Comments

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.

SlicingThis element introduces a set of slices on Observation.category.coding. The slices are unordered and Open, and can be differentiated using the following discriminators:
  • value @ system
27. Observation.category.coding:snomedCT
SliceNamesnomedCT
Definition

A reference to a code defined by a terminology system.

Control0..0*
TypeCoding
Summarytrue
Requirements

Allows for translations and alternate encodings within a code system. Also supports communication of the same instance to systems requiring different encodings.

Comments

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.

28. Observation.category:observationCategory
SliceNameobservationCategory
Definition

A code that classifies the general type of observation being made.

Control10..1*
BindingThe codes SHALL be taken from Observation Category CodesThe codes SHOULD be taken from Observation Category Codes

Codes for high level observation categories.

TypeCodeableConcept
Requirements

Used for filtering what observations are retrieved and displayed.

Comments

In addition to the required category valueset, this element allows various categorization schemes based on the owner’s definition of the category and effectively multiple categories can be used at once. The level of granularity is defined by the category concepts in the value set.

29. Observation.category:observationCategory.coding
Definition

A reference to a code defined by a terminology system.

Control0..*
TypeCoding
Summarytrue
Requirements

Allows for translations and alternate encodings within a code system. Also supports communication of the same instance to systems requiring different encodings.

Comments

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.

SlicingThis element introduces a set of slices on Observation.category.coding. The slices are unordered and Open, and can be differentiated using the following discriminators:
  • value @ system
30. Observation.category:observationCategory.coding.system
Definition

The identification of the code system that defines the meaning of the symbol in the code.

Control10..1
Typeuri
Summarytrue
Requirements

Need to be unambiguous about the source of the definition of the symbol.

Comments

The URI may be an OID (urn:oid:...) or a UUID (urn:uuid:...). OIDs and UUIDs SHALL be references to the HL7 OID registry. Otherwise, the URI should come from HL7's list of FHIR defined special URIs or it should de-reference to some definition that establish the system clearly and unambiguously.

Fixed Valuehttp://hl7.org/fhir/observation-category
31. Observation.category:observationCategory.coding.version
Definition

The version of the code system which was used when choosing this code. Note that a well-maintained code system does not need the version reported, because the meaning of codes is consistent across versions. However this cannot consistently be assured. and when the meaning is not guaranteed to be consistent, the version SHOULD be exchanged.

NoteThis is a business versionId, not a resource version id (see discussion)
Control0..01
Typestring
Summarytrue
Comments

Where the terminology does not clearly define what string should be used to identify code system versions, the recommendation is to use the date (expressed in FHIR date format) on which that version was officially published as the version date.

32. Observation.category:observationCategory.coding.code
Definition

A symbol in syntax defined by the system. The symbol may be a predefined code or an expression in a syntax defined by the coding system (e.g. post-coordination).

Control10..1
Typecode
Summarytrue
Requirements

Need to refer to a particular code in the system.

Fixed Valuevital-signs
33. Observation.category:observationCategory.coding.display
Definition

A representation of the meaning of the code in the system, following the rules of the system.

Control10..1
Typestring
Summarytrue
Requirements

Need to be able to carry a human-readable meaning of the code for readers that do not know the system.

Fixed ValueVital Signs
34. Observation.category:observationCategory.coding:snomedCT
SliceNamesnomedCT
Definition

A reference to a code defined by a terminology system.

Control0..0*
TypeCoding
Summarytrue
Requirements

Allows for translations and alternate encodings within a code system. Also supports communication of the same instance to systems requiring different encodings.

Comments

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.

35. Observation.code
Definition

Describes what was observed. Sometimes this is called the observation "name".

Control1..1
BindingThe codes SHOULD be taken from Vital SignsFor example codes, see LOINC Codes
TypeCodeableConcept
Must Supporttrue
Summarytrue
Requirements

Knowing what kind of observation is being made is essential to understanding the observation.

Alternate NamesName
36. Observation.code.coding
Definition

A reference to a code defined by a terminology system.

Control10..*
TypeCoding
Summarytrue
Requirements

Allows for translations and alternate encodings within a code system. Also supports communication of the same instance to systems requiring different encodings.

Comments

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.

SlicingThis element introduces a set of slices on Observation.code.coding. The slices are unordered and Open, and can be differentiated using the following discriminators:
  • value @ system
37. Observation.code.coding:snomedCT
SliceNamesnomedCT
Definition

A reference to a code defined by a terminology system.

Control0..1*
BindingThe codes SHOULD be taken from Care Connect Observation TypeFor codes, see (unbound)
TypeCoding
Must Supporttrue
Summarytrue
Requirements

Allows for translations and alternate encodings within a code system. Also supports communication of the same instance to systems requiring different encodings.

Comments

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.

38. Observation.code.coding:snomedCT.extension:snomedCTDescriptionID
SliceNamesnomedCTDescriptionID
Definition

The SNOMED CT Description ID for the display.

May be used to represent additional information that is not part of the basic definition of the element. In order to make the use of extensions safe and manageable, 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.

TypeExtension(Extension-coding-sctdescid) (Complex Extension)
39. Observation.code.coding:snomedCT.system
Definition

The identification of the code system that defines the meaning of the symbol in the code.

Control10..1
Typeuri
Summarytrue
Requirements

Need to be unambiguous about the source of the definition of the symbol.

Comments

The URI may be an OID (urn:oid:...) or a UUID (urn:uuid:...). OIDs and UUIDs SHALL be references to the HL7 OID registry. Otherwise, the URI should come from HL7's list of FHIR defined special URIs or it should de-reference to some definition that establish the system clearly and unambiguously.

Fixed Valuehttp://snomed.info/sct
40. Observation.code.coding:snomedCT.version
Definition

The version of the code system which was used when choosing this code. Note that a well-maintained code system does not need the version reported, because the meaning of codes is consistent across versions. However this cannot consistently be assured. and when the meaning is not guaranteed to be consistent, the version SHOULD be exchanged.

NoteThis is a business versionId, not a resource version id (see discussion)
Control0..01
Typestring
Summarytrue
Comments

Where the terminology does not clearly define what string should be used to identify code system versions, the recommendation is to use the date (expressed in FHIR date format) on which that version was officially published as the version date.

41. Observation.code.coding:snomedCT.code
Definition

A symbol in syntax defined by the system. The symbol may be a predefined code or an expression in a syntax defined by the coding system (e.g. post-coordination).

Control10..1
Typecode
Summarytrue
Requirements

Need to refer to a particular code in the system.

Fixed Value27113001
42. Observation.code.coding:snomedCT.display
Definition

A representation of the meaning of the code in the system, following the rules of the system.

Control10..1
Typestring
Summarytrue
Requirements

Need to be able to carry a human-readable meaning of the code for readers that do not know the system.

Fixed ValueBody weight
43. Observation.code.coding:loinc
SliceNameloinc
Definition

A reference to a code defined by a terminology system.

Control10..1*
TypeCoding
Summarytrue
Requirements

Allows for translations and alternate encodings within a code system. Also supports communication of the same instance to systems requiring different encodings.

Comments

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.

44. Observation.code.coding:loinc.system
Definition

The identification of the code system that defines the meaning of the symbol in the code.

Control0..1
Typeuri
Summarytrue
Requirements

Need to be unambiguous about the source of the definition of the symbol.

Comments

The URI may be an OID (urn:oid:...) or a UUID (urn:uuid:...). OIDs and UUIDs SHALL be references to the HL7 OID registry. Otherwise, the URI should come from HL7's list of FHIR defined special URIs or it should de-reference to some definition that establish the system clearly and unambiguously.

Fixed Valuehttp://loinc.org
45. Observation.code.coding:loinc.code
Definition

A symbol in syntax defined by the system. The symbol may be a predefined code or an expression in a syntax defined by the coding system (e.g. post-coordination).

Control0..1
Typecode
Summarytrue
Requirements

Need to refer to a particular code in the system.

Fixed Value29463-7
46. Observation.code.coding:loinc.display
Definition

A representation of the meaning of the code in the system, following the rules of the system.

Control0..1
Typestring
Summarytrue
Requirements

Need to be able to carry a human-readable meaning of the code for readers that do not know the system.

Fixed ValueBody weight
47. Observation.subject
Definition

The patient, or group of patients, location, or device whose characteristics (direct or indirect) are described by the observation and into whose record the observation is placed. Comments: Indirect characteristics may be those of a specimen, fetus, donor, other observer (for example a relative or EMT), or any observation made about the subject.

Control10..1
TypeReference(CareConnectPatient1|Patient|Group|Device|Location)
Must Supporttrue
Summarytrue
Requirements

Observations have no value if you don't know who or what they're about.

Comments

One would expect this element to be a cardinality of 1..1. The only circumstance in which the subject can be missing is when the observation is made by a device that does not know the patient. In this case, the observation SHALL be matched to a patient through some context/channel matching technique, and at this point, the observation should be updated.

If the target of the observation is different than the subject, the general extension observation-focal-subject. may be used. However, the distinction between the patient's own value for an observation versus that of the fetus, or the donor or blood product unit, etc., are often specified in the observation code.

48. Observation.subject.reference
Definition

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.

Control10..1 This element is affected by the following invariants: ref-1
Typestring
Summarytrue
Comments

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.

49. Observation.subject.display
Definition

Plain text narrative that identifies the resource in addition to the resource reference.

Control10..1
Typestring
Summarytrue
Comments

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.

50. Observation.effective[x]
Definition

The time or time-period the observed value is asserted as being true. For biological subjects - e.g. human patients - this is usually called the "physiologically relevant time". This is usually either the time of the procedure or of specimen collection, but very often the source of the date/time is not known, only the date/time itself.

Control10..1
TypeChoice of: dateTime, Period
[x] NoteSee Choice of Data Types for further information about how to use [x]
Must Supporttrue
Summarytrue
Requirements

Knowing when an observation was deemed true is important to its relevance as well as determining trends.

Alternate NamesOccurrence
Comments

At least a date should be present unless this observation is a historical report.

51. Observation.issued
Definition

The date and time this observation was made available to providers, typically after the results have been reviewed and verified.

Control0..01
Typeinstant
Summarytrue
Comments

Updated when the result is updated.

52. Observation.performer
Definition

Who was responsible for asserting the observed value as "true".

Control0..*
TypeReference(CareConnect-Practitioner-1|Practitioner|Organization|Patient|RelatedPerson)
Must Supporttrue
Summarytrue
Requirements

May give a degree of confidence in the observation and also indicates where follow-up questions should be directed.

53. Observation.performer.reference
Definition

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.

Control10..1 This element is affected by the following invariants: ref-1
Typestring
Summarytrue
Comments

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.

54. Observation.performer.display
Definition

Plain text narrative that identifies the resource in addition to the resource reference.

Control10..1
Typestring
Summarytrue
Comments

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.

55. Observation.value[x]
Definition

The information determined as a result of making the observation, if the information has a simple value.

Control10..1 This element is affected by the following invariants: obs-7
TypeChoice of: Quantity, dateTime, boolean, string, SampledData, Period, Ratio, Attachment, time, Range, CodeableConcept
[x] NoteSee Choice of Data Types for further information about how to use [x]
Must Supporttrue
Summarytrue
Requirements

An observation exists to have a value, though it may not if it is in error, or if it represents a group of observations.

Comments

Normally, an observation will have either a single value or a set of related observations. A few observations (e.g. Apgar score) may have both a value and related observations (for an Apgar score, the observations from which the measure is derived). If a value is present, the datatype for this element should be determined by Observation.code. This element has a variable name depending on the type as follows: valueQuantity, valueCodeableConcept, valueString, valueBoolean, valueRange, valueRatio, valueSampledData, valueAttachment, valueTime, valueDateTime, or valuePeriod. (The name format is "'value' + the type name" with a capital on the first letter of the type).

If the data element is usually coded or if the type associated with the Observation.value defines a coded value, use CodeableConcept instead of string datatype even if the value is uncoded text. A value set is bound to the ValueCodeableConcept element. For further discussion and examples see the notes section below.

56. Observation.dataAbsentReason
Definition

Provides a reason why the expected value in the element Observation.value[x] is missing.

Control0..01 This element is affected by the following invariants: obs-6
BindingThe codes SHALL be taken from Observation Value Absent ReasonThe codes SHALL be taken from Observation Value Absent Reason; other codes may be used where these codes are not suitable
TypeCodeableConcept
Must Supporttrue
Requirements

For many results it is necessary to handle exceptional values in measurements.

Comments

Null or exceptional values can be represented two ways in FHIR Observations. One way is to simply include them in the value set and represent the exceptions in the value. For example, measurement values for a serology test could be "detected", "not detected", "inconclusive", or "specimen unsatisfactory". The alternate way is to use the value element for actual observations and use the explicit dataAbsentReason element to record exceptional values. For example, the dataAbsentReason code "error" could be used when the measurement was not completed. Note that an observation may only be reported if there are values to report. For example differential cell counts values may be reported only when > 0. Because of these options, use-case agreements are required to interpret general observations for null or exceptional values.

57. Observation.interpretation
Definition

The assessment made based on the result of the observation. Intended as a simple compact code often placed adjacent to the result value in reports and flow sheets to signal the meaning/normalcy status of the result. Otherwise known as abnormal flag.

Control0..01
BindingThe codes SHALL be taken from Observation Interpretation CodesThe codes SHALL be taken from Observation Interpretation Codes; other codes may be used where these codes are not suitable
TypeCodeableConcept
Must Supporttrue
Requirements

For some results, particularly numeric results, an interpretation is necessary to fully understand the significance of a result.

Alternate NamesAbnormal Flag
58. Observation.comment
Definition

May include statements about significant, unexpected or unreliable values, or information about the source of the value where this may be relevant to the interpretation of the result.

Control0..1
Typestring
Must Supporttrue
Requirements

Need to be able to provide free text additional information.

59. Observation.bodySite
Definition

Indicates the site on the subject's body where the observation was made (i.e. the target site).

Control0..01
BindingThe codes SHALL be taken from SNOMED CT Body StructuresFor example codes, see SNOMED CT Body Structures
TypeCodeableConcept
Must Supporttrue
Comments

Only used if not implicit in code found in Observation.code. In many systems, this may be represented as a related observation instead of an inline component. If the use case requires BodySite to be handled as a separate resource (e.g. to identify and track separately) then use the standard extension body-site-instance.

60. Observation.specimen
Definition

The specimen that was used when this observation was made.

Control0..01
TypeReference(CareConnect-Specimen-1|Specimen)
Comments

Should only be used if not implicit in code found in Observation.code. Observations are not made on specimens themselves; they are made on a subject, but in many cases by the means of a specimen. Note that although specimens are often involved, they are not always tracked and reported explicitly. Also note that observation resources may be used in contexts that track the specimen explicitly (e.g. Diagnostic Report).

61. Observation.referenceRange
Definition

Guidance on how to interpret the value by comparison to a normal or recommended range.

Control0..0*
TypeBackboneElement
Must Supporttrue
Requirements

Knowing what values are considered "normal" can help evaluate the significance of a particular result. Need to be able to provide multiple reference ranges for different contexts.

Comments

Most observations only have one generic reference range. Systems MAY choose to restrict to only supplying the relevant reference range based on knowledge about the patient (e.g., specific to the patient's age, gender, weight and other factors), but this may not be possible or appropriate. Whenever more than one reference range is supplied, the differences between them SHOULD be provided in the reference range and/or age properties.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() | (children().count() > id.count()))
obs-3: Must have at least a low or a high or text (: low.exists() or high.exists() or text.exists())
62. Observation.related
Definition

A reference to another resource (usually another Observation) whose relationship is defined by the relationship type code.

Control0..*
TypeBackboneElement
Must Supporttrue
Summarytrue
Requirements

Normally, an observation will have either a value or a set of related observations. A few observations (e.g. Apgar score) may have both a value and a set of related observations or sometimes a QuestionnaireResponse from which the measure is derived.

Comments

For a discussion on the ways Observations can assembled in groups together see Notes below.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() | (children().count() > id.count()))
63. Observation.related.modifierExtension
Definition

May be used to represent additional information that is not part of the basic definition of the element, and that modifies the understanding of the element that contains it. Usually modifier elements provide negation or qualification. In order to make the use of extensions safe and manageable, 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.

Control0..*
TypeExtension
Is Modifiertrue
Summarytrue
Alternate Namesextensions, user content, modifiers
Comments

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

64. Observation.related.type
Definition

A code specifying the kind of relationship that exists with the target resource.

Control10..1
BindingThe codes SHALL be taken from ObservationRelationshipType

Codes specifying how two observations are related.

Typecode
Must Supporttrue
Requirements

A relationship type SHOULD be provided.

Comments

The "derived-from" type is the only logical choice when referencing the QuestionnaireAnswer resource.

Fixed Valuederived-from
65. Observation.related.target
Definition

A reference to the observation or QuestionnaireResponse resource that is related to this observation.

Control1..1
TypeReference(CareConnect-Observation-1|Observation|QuestionnaireResponse|Sequence)
Must Supporttrue
66. Observation.component
Definition

Some observations have multiple component observations. These component observations are expressed as separate code value pairs that share the same attributes. Examples include systolic and diastolic component observations for blood pressure measurement and multiple component observations for genetics observations.

Control0..0*
TypeBackboneElement
Must Supporttrue
Summarytrue
Requirements

Component observations share the same attributes in the Observation resource as the primary observation and are always treated a part of a single observation (they are not separable). However, the reference range for the primary observation value is not inherited by the component values and is required when appropriate for each component observation.

Comments

For a discussion on the ways Observations can be assembled in groups together see Notes below.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() | (children().count() > id.count()))

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

1. Observation
Definition

Measurements and simple assertions made about a patient, device or other subject.

Control0..*
Alternate NamesVital Signs, Measurement, Results, Tests
Comments

Used for simple observations such as device measurements, laboratory atomic results, vital signs, height, weight, smoking status, comments, etc. Other resources are used to provide context for observations such as lab reports, etc.

2. Observation.id
Definition

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

Control0..1
Typeid
Must Supporttrue
Summarytrue
Comments

The only time that a resource does not have an id is when it is being submitted to the server using a create operation.

3. Observation.meta
Definition

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

Control0..1
TypeMeta
Summarytrue
4. Observation.meta.id
Definition

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

Control0..1
Typestring
XML RepresentationIn the XML format, this property is represented as an attribute.
5. Observation.meta.extension
Definition

May be used to represent additional information that is not part of the basic definition of the element. In order to make the use of extensions safe and manageable, 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.

Control0..*
TypeExtension
Alternate Namesextensions, user content
Comments

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

SlicingThis element introduces a set of slices on Observation.meta.extension. The slices are unordered and Open, and can be differentiated using the following discriminators:
  • value @ url
6. Observation.meta.versionId
Definition

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

Control0..1
Typeid
Must Supporttrue
Summarytrue
Comments

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.

7. Observation.meta.lastUpdated
Definition

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

Control0..1
Typeinstant
Must Supporttrue
Summarytrue
Comments

This value is always populated except when the resource is first being created. The server / resource manager sets this value; what a client provides is irrelevant.

8. Observation.meta.profile
Definition

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

Control0..*
Typeuri
Must Supporttrue
Summarytrue
Comments

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.

9. Observation.meta.security
Definition

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

Control0..*
BindingThe codes SHALL be taken from All Security Labels; other codes may be used where these codes are not suitable Security Labels from the Healthcare Privacy and Security Classification System
TypeCoding
Summarytrue
Comments

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.

10. Observation.meta.tag
Definition

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.

Control0..*
BindingFor example codes, see Common Tags Codes that represent various types of tags, commonly workflow-related; e.g. "Needs review by Dr. Jones
TypeCoding
Summarytrue
Comments

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.

SlicingThis element introduces a set of slices on Observation.meta.tag. The slices are unordered and Open, and can be differentiated using the following discriminators:
  • value @ system
11. Observation.meta.tag:Source
SliceNameSource
Definition

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.

Control0..1
BindingFor example codes, see Common Tags Codes that represent various types of tags, commonly workflow-related; e.g. "Needs review by Dr. Jones
TypeCoding
Must Supporttrue
Summarytrue
Comments

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.

12. Observation.meta.tag:Source.id
Definition

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

Control0..1
Typestring
XML RepresentationIn the XML format, this property is represented as an attribute.
13. Observation.meta.tag:Source.extension
Definition

May be used to represent additional information that is not part of the basic definition of the element. In order to make the use of extensions safe and manageable, 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.

Control0..*
TypeExtension
Alternate Namesextensions, user content
Comments

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

SlicingThis element introduces a set of slices on Observation.meta.tag.extension. The slices are unordered and Open, and can be differentiated using the following discriminators:
  • value @ url
14. Observation.meta.tag:Source.system
Definition

The identification of the code system that defines the meaning of the symbol in the code.

Control1..1
Typeuri
Summarytrue
Requirements

Need to be unambiguous about the source of the definition of the symbol.

Comments

The URI may be an OID (urn:oid:...) or a UUID (urn:uuid:...). OIDs and UUIDs SHALL be references to the HL7 OID registry. Otherwise, the URI should come from HL7's list of FHIR defined special URIs or it should de-reference to some definition that establish the system clearly and unambiguously.

Fixed Valuehttps://yhcr.nhs.uk/Source
15. Observation.meta.tag:Source.version
Definition

The version of the code system which was used when choosing this code. Note that a well-maintained code system does not need the version reported, because the meaning of codes is consistent across versions. However this cannot consistently be assured. and when the meaning is not guaranteed to be consistent, the version SHOULD be exchanged.

NoteThis is a business versionId, not a resource version id (see discussion)
Control0..1
Typestring
Summarytrue
Comments

Where the terminology does not clearly define what string should be used to identify code system versions, the recommendation is to use the date (expressed in FHIR date format) on which that version was officially published as the version date.

16. Observation.meta.tag:Source.code
Definition

A symbol in syntax defined by the system. The symbol may be a predefined code or an expression in a syntax defined by the coding system (e.g. post-coordination).

Control1..1
Typecode
Must Supporttrue
Summarytrue
Requirements

Need to refer to a particular code in the system.

17. Observation.meta.tag:Source.display
Definition

A representation of the meaning of the code in the system, following the rules of the system.

Control1..1
Typestring
Must Supporttrue
Summarytrue
Requirements

Need to be able to carry a human-readable meaning of the code for readers that do not know the system.

18. Observation.meta.tag:Source.userSelected
Definition

Indicates that this coding was chosen by a user directly - i.e. off a pick list of available items (codes or displays).

Control0..1
Typeboolean
Summarytrue
Requirements

This has been identified as a clinical safety criterium - that this exact system/code pair was chosen explicitly, rather than inferred by the system based on some rules or language processing.

Comments

Amongst a set of alternatives, a directly chosen code is the most appropriate starting point for new translations. There is some ambiguity about what exactly 'directly chosen' implies, and trading partner agreement may be needed to clarify the use of this element and its consequences more completely.

19. Observation.meta.tag:Provenance
SliceNameProvenance
Definition

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.

Control0..1
BindingFor example codes, see Common Tags Codes that represent various types of tags, commonly workflow-related; e.g. "Needs review by Dr. Jones
TypeCoding
Must Supporttrue
Summarytrue
Comments

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.

20. Observation.meta.tag:Provenance.id
Definition

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

Control0..1
Typestring
XML RepresentationIn the XML format, this property is represented as an attribute.
21. Observation.meta.tag:Provenance.extension
Definition

May be used to represent additional information that is not part of the basic definition of the element. In order to make the use of extensions safe and manageable, 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.

Control0..*
TypeExtension
Alternate Namesextensions, user content
Comments

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

SlicingThis element introduces a set of slices on Observation.meta.tag.extension. The slices are unordered and Open, and can be differentiated using the following discriminators:
  • value @ url
22. Observation.meta.tag:Provenance.system
Definition

The identification of the code system that defines the meaning of the symbol in the code.

Control1..1
Typeuri
Summarytrue
Requirements

Need to be unambiguous about the source of the definition of the symbol.

Comments

The URI may be an OID (urn:oid:...) or a UUID (urn:uuid:...). OIDs and UUIDs SHALL be references to the HL7 OID registry. Otherwise, the URI should come from HL7's list of FHIR defined special URIs or it should de-reference to some definition that establish the system clearly and unambiguously.

Fixed Valuehttps://yhcr.nhs.uk/Provenance
23. Observation.meta.tag:Provenance.version
Definition

The version of the code system which was used when choosing this code. Note that a well-maintained code system does not need the version reported, because the meaning of codes is consistent across versions. However this cannot consistently be assured. and when the meaning is not guaranteed to be consistent, the version SHOULD be exchanged.

NoteThis is a business versionId, not a resource version id (see discussion)
Control0..1
Typestring
Summarytrue
Comments

Where the terminology does not clearly define what string should be used to identify code system versions, the recommendation is to use the date (expressed in FHIR date format) on which that version was officially published as the version date.

24. Observation.meta.tag:Provenance.code
Definition

A symbol in syntax defined by the system. The symbol may be a predefined code or an expression in a syntax defined by the coding system (e.g. post-coordination).

Control1..1
Typecode
Must Supporttrue
Summarytrue
Requirements

Need to refer to a particular code in the system.

25. Observation.meta.tag:Provenance.display
Definition

A representation of the meaning of the code in the system, following the rules of the system.

Control1..1
Typestring
Must Supporttrue
Summarytrue
Requirements

Need to be able to carry a human-readable meaning of the code for readers that do not know the system.

26. Observation.meta.tag:Provenance.userSelected
Definition

Indicates that this coding was chosen by a user directly - i.e. off a pick list of available items (codes or displays).

Control0..1
Typeboolean
Summarytrue
Requirements

This has been identified as a clinical safety criterium - that this exact system/code pair was chosen explicitly, rather than inferred by the system based on some rules or language processing.

Comments

Amongst a set of alternatives, a directly chosen code is the most appropriate starting point for new translations. There is some ambiguity about what exactly 'directly chosen' implies, and trading partner agreement may be needed to clarify the use of this element and its consequences more completely.

27. Observation.implicitRules
Definition

A reference to a set of rules that were followed when the resource was constructed, and which must be understood when processing the content.

Control0..1
Typeuri
Is Modifiertrue
Summarytrue
Comments

Asserting this rule set restricts the content to be only understood by a limited set of trading partners. This inherently limits the usefulness of the data in the long term. However, the existing health eco-system is highly fractured, and not yet ready to define, collect, and exchange data in a generally computable sense. Wherever possible, implementers and/or specification writers should avoid using this element.

This element is labelled as a modifier because the implicit rules may provide additional knowledge about the resource that modifies it's meaning or interpretation.

28. Observation.language
Definition

The base language in which the resource is written.

Control0..1
BindingThe codes SHALL be taken from Common Languages; other codes may be used where these codes are not suitable A human language
Additional BindingsPurpose
AllLanguagesMax Binding
Typecode
Comments

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

29. Observation.text
Definition

A human-readable narrative that contains a summary of the resource, and may 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.

Control0..1 This element is affected by the following invariants: dom-1
TypeNarrative
Alternate Namesnarrative, html, xhtml, display
Comments

Contained resources do not have 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 in formation is added later.

30. Observation.contained
Definition

These resources do not have an independent existence apart from the resource that contains them - they cannot be identified independently, and nor can they have their own independent transaction scope.

Control0..*
TypeResource
Alternate Namesinline resources, anonymous resources, contained resources
Comments

This should never be done when the content can be identified properly, as once identification is lost, it is extremely difficult (and context dependent) to restore it again.

31. Observation.extension
Definition

An Extension

Control0..*
TypeExtension
SlicingThis element introduces a set of slices on Observation.extension. The slices are unordered and Open, and can be differentiated using the following discriminators:
  • value @ url
32. Observation.extension:reason
SliceNamereason
Definition

Reason resource added/performed/given.

Control0..0 This element is affected by the following invariants: ele-1
TypeExtension(Extension-CareConnect-ReasonCondition-1) (Extension Type: Choice of: CodeableConcept, Reference(CareConnect-Condition-1))
InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() | (children().count() > id.count()))
ext-1: Must have either extensions or value[x], not both (: extension.exists() != value.exists())
33. Observation.extension:valuePrecision
SliceNamevaluePrecision
Definition

Explicit precision of the number. This is the number of significant decimal places after the decimal point, irrespective of how many are actually present in the explicitly represented decimal.

Control0..0
TypeExtension(ExtensionInterweaveValuePrecision) (Extension Type: integer)
Comments

The presence of this extension does not change conformance expectations with regard to rendering and calculations that use the number - these are still based on the raw decimal value. Applications that perform calculations SHALL ensure that this extension is removed or updated to the correct precision value if the number is changed. Applications should consider using the exponential form (e.g. 2.10e3) on the raw decimal to manage significant figures, but should be mindful of human display when doing so.

34. Observation.modifierExtension
Definition

May be used to represent additional information that is not part of the basic definition of the resource, and that modifies the understanding of the element that contains it. Usually modifier elements provide negation or qualification. In order to make the use of extensions safe and manageable, 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.

Control0..*
TypeExtension
Is Modifiertrue
Alternate Namesextensions, user content
Comments

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

35. Observation.identifier
Definition

A unique identifier assigned to this observation.

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

Allows observations to be distinguished and referenced.

36. Observation.identifier.id
Definition

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

Control0..1
Typestring
XML RepresentationIn the XML format, this property is represented as an attribute.
37. Observation.identifier.extension
Definition

May be used to represent additional information that is not part of the basic definition of the element. In order to make the use of extensions safe and manageable, 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.

Control0..*
TypeExtension
Alternate Namesextensions, user content
Comments

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

SlicingThis element introduces a set of slices on Observation.identifier.extension. The slices are unordered and Open, and can be differentiated using the following discriminators:
  • value @ url
38. Observation.identifier.use
Definition

The purpose of this identifier.

Control0..1
BindingThe codes SHALL be taken from IdentifierUse Identifies the purpose for this identifier, if known
Typecode
Is Modifiertrue
Summarytrue
Requirements

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

Comments

This is labeled as "Is Modifier" because applications should not mistake a temporary id for a permanent one. Applications can assume that an identifier is permanent unless it explicitly says that it is temporary.

39. Observation.identifier.type
Definition

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

Control0..1
BindingThe codes SHALL be taken from Identifier Type Codes; other codes may be used where these codes are not suitable A coded type for an identifier that can be used to determine which identifier to use for a specific purpose
TypeCodeableConcept
Summarytrue
Requirements

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

Comments

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.

40. Observation.identifier.system
Definition

Establishes the namespace for the value - that is, a URL that describes a set values that are unique.

Control1..1
Typeuri
Summarytrue
Requirements

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.

Example
General:http://www.acme.com/identifiers/patient
41. Observation.identifier.value
Definition

The portion of the identifier typically relevant to the user and which is unique within the context of the system.

Control1..1
Typestring
Summarytrue
Comments

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 Rendered Value extension.

Example
General:123456
42. Observation.identifier.period
Definition

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

Control0..1
TypePeriod
Summarytrue
43. Observation.identifier.assigner
Definition

Organization that issued/manages the identifier.

Control0..1
TypeReference(CareConnect-Organization-1)
Summarytrue
Comments

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.

44. Observation.basedOn
Definition

A plan, proposal or order that is fulfilled in whole or in part by this event.

Control0..*
TypeReference(CarePlan|DeviceRequest|ImmunizationRecommendation|MedicationRequest|NutritionOrder|ProcedureRequest|ReferralRequest)
Summarytrue
Requirements

Allows tracing of authorization for the event and tracking whether proposals/recommendations were acted upon.

Alternate NamesFulfills
45. Observation.status
Definition

The status of the result value.

Control1..1
BindingThe codes SHALL be taken from ObservationStatus
Typecode
Is Modifiertrue
Must Supporttrue
Summarytrue
Requirements

Need to track the status of individual results. Some results are finalized before the whole report is finalized.

Comments

This element is labeled as a modifier because the status contains codes that mark the resource as not currently valid.

Fixed Valuefinal
46. Observation.category
Definition

A code that classifies the general type of observation being made.

Control1..1
BindingThe codes SHOULD be taken from Observation Category Codes Codes for high level observation categories
TypeCodeableConcept
Must Supporttrue
Requirements

Used for filtering what observations are retrieved and displayed.

Comments

In addition to the required category valueset, this element allows various categorization schemes based on the owner’s definition of the category and effectively multiple categories can be used at once. The level of granularity is defined by the category concepts in the value set.

SlicingThis element introduces a set of slices on Observation.category. The slices are unordered and Open, and can be differentiated using the following discriminators:
  • value @ coding.system
47. Observation.category.id
Definition

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

Control0..1
Typestring
XML RepresentationIn the XML format, this property is represented as an attribute.
48. Observation.category.extension
Definition

May be used to represent additional information that is not part of the basic definition of the element. In order to make the use of extensions safe and manageable, 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.

Control0..*
TypeExtension
Alternate Namesextensions, user content
Comments

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

SlicingThis element introduces a set of slices on Observation.category.extension. The slices are unordered and Open, and can be differentiated using the following discriminators:
  • value @ url
49. Observation.category.coding
Definition

A reference to a code defined by a terminology system.

Control0..*
TypeCoding
Summarytrue
Requirements

Allows for translations and alternate encodings within a code system. Also supports communication of the same instance to systems requiring different encodings.

Comments

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.

SlicingThis element introduces a set of slices on Observation.category.coding. The slices are unordered and Open, and can be differentiated using the following discriminators:
  • value @ system
50. Observation.category.coding:snomedCT
SliceNamesnomedCT
Definition

A reference to a code defined by a terminology system.

Control0..0
TypeCoding
Summarytrue
Requirements

Allows for translations and alternate encodings within a code system. Also supports communication of the same instance to systems requiring different encodings.

Comments

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.

51. Observation.category.text
Definition

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.

Control0..1
Typestring
Summarytrue
Requirements

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.

Comments

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

52. Observation.category:observationCategory
SliceNameobservationCategory
Definition

A code that classifies the general type of observation being made.

Control1..1
BindingThe codes SHALL be taken from Observation Category Codes Codes for high level observation categories
TypeCodeableConcept
Requirements

Used for filtering what observations are retrieved and displayed.

Comments

In addition to the required category valueset, this element allows various categorization schemes based on the owner’s definition of the category and effectively multiple categories can be used at once. The level of granularity is defined by the category concepts in the value set.

53. Observation.category:observationCategory.id
Definition

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

Control0..1
Typestring
XML RepresentationIn the XML format, this property is represented as an attribute.
54. Observation.category:observationCategory.extension
Definition

May be used to represent additional information that is not part of the basic definition of the element. In order to make the use of extensions safe and manageable, 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.

Control0..*
TypeExtension
Alternate Namesextensions, user content
Comments

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

SlicingThis element introduces a set of slices on Observation.category.extension. The slices are unordered and Open, and can be differentiated using the following discriminators:
  • value @ url
55. Observation.category:observationCategory.coding
Definition

A reference to a code defined by a terminology system.

Control0..*
TypeCoding
Summarytrue
Requirements

Allows for translations and alternate encodings within a code system. Also supports communication of the same instance to systems requiring different encodings.

Comments

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.

SlicingThis element introduces a set of slices on Observation.category.coding. The slices are unordered and Open, and can be differentiated using the following discriminators:
  • value @ system
56. Observation.category:observationCategory.coding.id
Definition

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

Control0..1
Typestring
XML RepresentationIn the XML format, this property is represented as an attribute.
57. Observation.category:observationCategory.coding.extension
Definition

May be used to represent additional information that is not part of the basic definition of the element. In order to make the use of extensions safe and manageable, 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.

Control0..*
TypeExtension
Alternate Namesextensions, user content
Comments

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

SlicingThis element introduces a set of slices on Observation.category.coding.extension. The slices are unordered and Open, and can be differentiated using the following discriminators:
  • value @ url
58. Observation.category:observationCategory.coding.system
Definition

The identification of the code system that defines the meaning of the symbol in the code.

Control1..1
Typeuri
Summarytrue
Requirements

Need to be unambiguous about the source of the definition of the symbol.

Comments

The URI may be an OID (urn:oid:...) or a UUID (urn:uuid:...). OIDs and UUIDs SHALL be references to the HL7 OID registry. Otherwise, the URI should come from HL7's list of FHIR defined special URIs or it should de-reference to some definition that establish the system clearly and unambiguously.

Fixed Valuehttp://hl7.org/fhir/observation-category
59. Observation.category:observationCategory.coding.version
Definition

The version of the code system which was used when choosing this code. Note that a well-maintained code system does not need the version reported, because the meaning of codes is consistent across versions. However this cannot consistently be assured. and when the meaning is not guaranteed to be consistent, the version SHOULD be exchanged.

NoteThis is a business versionId, not a resource version id (see discussion)
Control0..0
Typestring
Summarytrue
Comments

Where the terminology does not clearly define what string should be used to identify code system versions, the recommendation is to use the date (expressed in FHIR date format) on which that version was officially published as the version date.

60. Observation.category:observationCategory.coding.code
Definition

A symbol in syntax defined by the system. The symbol may be a predefined code or an expression in a syntax defined by the coding system (e.g. post-coordination).

Control1..1
Typecode
Summarytrue
Requirements

Need to refer to a particular code in the system.

Fixed Valuevital-signs
61. Observation.category:observationCategory.coding.display
Definition

A representation of the meaning of the code in the system, following the rules of the system.

Control1..1
Typestring
Summarytrue
Requirements

Need to be able to carry a human-readable meaning of the code for readers that do not know the system.

Fixed ValueVital Signs
62. Observation.category:observationCategory.coding.userSelected
Definition

Indicates that this coding was chosen by a user directly - i.e. off a pick list of available items (codes or displays).

Control0..1
Typeboolean
Summarytrue
Requirements

This has been identified as a clinical safety criterium - that this exact system/code pair was chosen explicitly, rather than inferred by the system based on some rules or language processing.

Comments

Amongst a set of alternatives, a directly chosen code is the most appropriate starting point for new translations. There is some ambiguity about what exactly 'directly chosen' implies, and trading partner agreement may be needed to clarify the use of this element and its consequences more completely.

63. Observation.category:observationCategory.coding:snomedCT
SliceNamesnomedCT
Definition

A reference to a code defined by a terminology system.

Control0..0
TypeCoding
Summarytrue
Requirements

Allows for translations and alternate encodings within a code system. Also supports communication of the same instance to systems requiring different encodings.

Comments

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.

64. Observation.category:observationCategory.text
Definition

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.

Control0..1
Typestring
Summarytrue
Requirements

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.

Comments

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

65. Observation.code
Definition

Describes what was observed. Sometimes this is called the observation "name".

Control1..1
BindingThe codes SHOULD be taken from Vital Signs
TypeCodeableConcept
Must Supporttrue
Summarytrue
Requirements

Knowing what kind of observation is being made is essential to understanding the observation.

Alternate NamesName
66. Observation.code.id
Definition

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

Control0..1
Typestring
XML RepresentationIn the XML format, this property is represented as an attribute.
67. Observation.code.extension
Definition

May be used to represent additional information that is not part of the basic definition of the element. In order to make the use of extensions safe and manageable, 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.

Control0..*
TypeExtension
Alternate Namesextensions, user content
Comments

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

SlicingThis element introduces a set of slices on Observation.code.extension. The slices are unordered and Open, and can be differentiated using the following discriminators:
  • value @ url
68. Observation.code.coding
Definition

A reference to a code defined by a terminology system.

Control1..*
TypeCoding
Summarytrue
Requirements

Allows for translations and alternate encodings within a code system. Also supports communication of the same instance to systems requiring different encodings.

Comments

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.

SlicingThis element introduces a set of slices on Observation.code.coding. The slices are unordered and Open, and can be differentiated using the following discriminators:
  • value @ system
69. Observation.code.coding:snomedCT
SliceNamesnomedCT
Definition

A reference to a code defined by a terminology system.

Control0..1
BindingThe codes SHOULD be taken from Care Connect Observation Type
TypeCoding
Must Supporttrue
Summarytrue
Requirements

Allows for translations and alternate encodings within a code system. Also supports communication of the same instance to systems requiring different encodings.

Comments

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.

70. Observation.code.coding:snomedCT.id
Definition

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

Control0..1
Typestring
XML RepresentationIn the XML format, this property is represented as an attribute.
71. Observation.code.coding:snomedCT.extension
Definition

An Extension

Control0..*
TypeExtension
SlicingThis element introduces a set of slices on Observation.code.coding.extension. The slices are unordered and Open, and can be differentiated using the following discriminators:
  • value @ url
72. Observation.code.coding:snomedCT.extension:snomedCTDescriptionID
SliceNamesnomedCTDescriptionID
Definition

The SNOMED CT Description ID for the display.

Control0..*
TypeExtension(Extension-coding-sctdescid) (Complex Extension)
73. Observation.code.coding:snomedCT.system
Definition

The identification of the code system that defines the meaning of the symbol in the code.

Control1..1
Typeuri
Summarytrue
Requirements

Need to be unambiguous about the source of the definition of the symbol.

Comments

The URI may be an OID (urn:oid:...) or a UUID (urn:uuid:...). OIDs and UUIDs SHALL be references to the HL7 OID registry. Otherwise, the URI should come from HL7's list of FHIR defined special URIs or it should de-reference to some definition that establish the system clearly and unambiguously.

Fixed Valuehttp://snomed.info/sct
74. Observation.code.coding:snomedCT.version
Definition

The version of the code system which was used when choosing this code. Note that a well-maintained code system does not need the version reported, because the meaning of codes is consistent across versions. However this cannot consistently be assured. and when the meaning is not guaranteed to be consistent, the version SHOULD be exchanged.

NoteThis is a business versionId, not a resource version id (see discussion)
Control0..0
Typestring
Summarytrue
Comments

Where the terminology does not clearly define what string should be used to identify code system versions, the recommendation is to use the date (expressed in FHIR date format) on which that version was officially published as the version date.

75. Observation.code.coding:snomedCT.code
Definition

A symbol in syntax defined by the system. The symbol may be a predefined code or an expression in a syntax defined by the coding system (e.g. post-coordination).

Control1..1
Typecode
Summarytrue
Requirements

Need to refer to a particular code in the system.

Fixed Value27113001
76. Observation.code.coding:snomedCT.display
Definition

A representation of the meaning of the code in the system, following the rules of the system.

Control1..1
Typestring
Summarytrue
Requirements

Need to be able to carry a human-readable meaning of the code for readers that do not know the system.

Fixed ValueBody weight
77. Observation.code.coding:snomedCT.userSelected
Definition

Indicates that this coding was chosen by a user directly - i.e. off a pick list of available items (codes or displays).

Control0..1
Typeboolean
Summarytrue
Requirements

This has been identified as a clinical safety criterium - that this exact system/code pair was chosen explicitly, rather than inferred by the system based on some rules or language processing.

Comments

Amongst a set of alternatives, a directly chosen code is the most appropriate starting point for new translations. There is some ambiguity about what exactly 'directly chosen' implies, and trading partner agreement may be needed to clarify the use of this element and its consequences more completely.

78. Observation.code.coding:loinc
SliceNameloinc
Definition

A reference to a code defined by a terminology system.

Control1..1
TypeCoding
Summarytrue
Requirements

Allows for translations and alternate encodings within a code system. Also supports communication of the same instance to systems requiring different encodings.

Comments

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.

79. Observation.code.coding:loinc.id
Definition

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

Control0..1
Typestring
XML RepresentationIn the XML format, this property is represented as an attribute.
80. Observation.code.coding:loinc.extension
Definition

May be used to represent additional information that is not part of the basic definition of the element. In order to make the use of extensions safe and manageable, 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.

Control0..*
TypeExtension
Alternate Namesextensions, user content
Comments

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

SlicingThis element introduces a set of slices on Observation.code.coding.extension. The slices are unordered and Open, and can be differentiated using the following discriminators:
  • value @ url
81. Observation.code.coding:loinc.system
Definition

The identification of the code system that defines the meaning of the symbol in the code.

Control0..1
Typeuri
Summarytrue
Requirements

Need to be unambiguous about the source of the definition of the symbol.

Comments

The URI may be an OID (urn:oid:...) or a UUID (urn:uuid:...). OIDs and UUIDs SHALL be references to the HL7 OID registry. Otherwise, the URI should come from HL7's list of FHIR defined special URIs or it should de-reference to some definition that establish the system clearly and unambiguously.

Fixed Valuehttp://loinc.org
82. Observation.code.coding:loinc.version
Definition

The version of the code system which was used when choosing this code. Note that a well-maintained code system does not need the version reported, because the meaning of codes is consistent across versions. However this cannot consistently be assured. and when the meaning is not guaranteed to be consistent, the version SHOULD be exchanged.

NoteThis is a business versionId, not a resource version id (see discussion)
Control0..1
Typestring
Summarytrue
Comments

Where the terminology does not clearly define what string should be used to identify code system versions, the recommendation is to use the date (expressed in FHIR date format) on which that version was officially published as the version date.

83. Observation.code.coding:loinc.code
Definition

A symbol in syntax defined by the system. The symbol may be a predefined code or an expression in a syntax defined by the coding system (e.g. post-coordination).

Control0..1
Typecode
Summarytrue
Requirements

Need to refer to a particular code in the system.

Fixed Value29463-7
84. Observation.code.coding:loinc.display
Definition

A representation of the meaning of the code in the system, following the rules of the system.

Control0..1
Typestring
Summarytrue
Requirements

Need to be able to carry a human-readable meaning of the code for readers that do not know the system.

Fixed ValueBody weight
85. Observation.code.coding:loinc.userSelected
Definition

Indicates that this coding was chosen by a user directly - i.e. off a pick list of available items (codes or displays).

Control0..1
Typeboolean
Summarytrue
Requirements

This has been identified as a clinical safety criterium - that this exact system/code pair was chosen explicitly, rather than inferred by the system based on some rules or language processing.

Comments

Amongst a set of alternatives, a directly chosen code is the most appropriate starting point for new translations. There is some ambiguity about what exactly 'directly chosen' implies, and trading partner agreement may be needed to clarify the use of this element and its consequences more completely.

86. Observation.code.text
Definition

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.

Control0..1
Typestring
Summarytrue
Requirements

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.

Comments

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

87. Observation.subject
Definition

The patient, or group of patients, location, or device whose characteristics (direct or indirect) are described by the observation and into whose record the observation is placed. Comments: Indirect characteristics may be those of a specimen, fetus, donor, other observer (for example a relative or EMT), or any observation made about the subject.

Control1..1
TypeReference(CareConnectPatient1)
Must Supporttrue
Summarytrue
Requirements

Observations have no value if you don't know who or what they're about.

Comments

One would expect this element to be a cardinality of 1..1. The only circumstance in which the subject can be missing is when the observation is made by a device that does not know the patient. In this case, the observation SHALL be matched to a patient through some context/channel matching technique, and at this point, the observation should be updated.

If the target of the observation is different than the subject, the general extension observation-focal-subject. may be used. However, the distinction between the patient's own value for an observation versus that of the fetus, or the donor or blood product unit, etc., are often specified in the observation code.

88. Observation.subject.id
Definition

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

Control0..1
Typestring
XML RepresentationIn the XML format, this property is represented as an attribute.
89. Observation.subject.extension
Definition

May be used to represent additional information that is not part of the basic definition of the element. In order to make the use of extensions safe and manageable, 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.

Control0..*
TypeExtension
Alternate Namesextensions, user content
Comments

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

SlicingThis element introduces a set of slices on Observation.subject.extension. The slices are unordered and Open, and can be differentiated using the following discriminators:
  • value @ url
90. Observation.subject.reference
Definition

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.

Control1..1 This element is affected by the following invariants: ref-1
Typestring
Summarytrue
Comments

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.

91. Observation.subject.identifier
Definition

An identifier for the other resource. This is used when there is no way to reference the other resource directly, either because the entity 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.

NoteThis is a business identifier, not a resource identifier (see discussion)
Control0..1
TypeIdentifier
Summarytrue
Comments

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.

92. Observation.subject.display
Definition

Plain text narrative that identifies the resource in addition to the resource reference.

Control1..1
Typestring
Summarytrue
Comments

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.

93. Observation.context
Definition

The healthcare event (e.g. a patient and healthcare provider interaction) during which this observation is made.

Control0..1
TypeReference(CareConnect-Encounter-1)
Requirements

For some observations it may be important to know the link between an observation and a particular encounter.

Alternate NamesEncounter
Comments

This will typically be the encounter the event occurred within, but some events may be initiated prior to or after the official completion of an encounter or episode but still be tied to the context of the encounter or episode (e.g. pre-admission lab tests).

94. Observation.effective[x]
Definition

The time or time-period the observed value is asserted as being true. For biological subjects - e.g. human patients - this is usually called the "physiologically relevant time". This is usually either the time of the procedure or of specimen collection, but very often the source of the date/time is not known, only the date/time itself.

Control1..1
TypedateTime
[x] NoteSee Choice of Data Types for further information about how to use [x]
Must Supporttrue
Summarytrue
Requirements

Knowing when an observation was deemed true is important to its relevance as well as determining trends.

Alternate NamesOccurrence
Comments

At least a date should be present unless this observation is a historical report.

95. Observation.issued
Definition

The date and time this observation was made available to providers, typically after the results have been reviewed and verified.

Control0..0
Typeinstant
Summarytrue
Comments

Updated when the result is updated.

96. Observation.performer
Definition

Who was responsible for asserting the observed value as "true".

Control0..*
TypeReference(CareConnect-Practitioner-1)
Must Supporttrue
Summarytrue
Requirements

May give a degree of confidence in the observation and also indicates where follow-up questions should be directed.

97. Observation.performer.id
Definition

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

Control0..1
Typestring
XML RepresentationIn the XML format, this property is represented as an attribute.
98. Observation.performer.extension
Definition

May be used to represent additional information that is not part of the basic definition of the element. In order to make the use of extensions safe and manageable, 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.

Control0..*
TypeExtension
Alternate Namesextensions, user content
Comments

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

SlicingThis element introduces a set of slices on Observation.performer.extension. The slices are unordered and Open, and can be differentiated using the following discriminators:
  • value @ url
99. Observation.performer.reference
Definition

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.

Control1..1 This element is affected by the following invariants: ref-1
Typestring
Summarytrue
Comments

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.

100. Observation.performer.identifier
Definition

An identifier for the other resource. This is used when there is no way to reference the other resource directly, either because the entity 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.

NoteThis is a business identifier, not a resource identifier (see discussion)
Control0..1
TypeIdentifier
Summarytrue
Comments

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.

101. Observation.performer.display
Definition

Plain text narrative that identifies the resource in addition to the resource reference.

Control1..1
Typestring
Summarytrue
Comments

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.

102. Observation.value[x]
Definition

The information determined as a result of making the observation, if the information has a simple value.

Control1..1 This element is affected by the following invariants: obs-7
TypeQuantity
[x] NoteSee Choice of Data Types for further information about how to use [x]
Must Supporttrue
Summarytrue
Requirements

An observation exists to have a value, though it may not if it is in error, or if it represents a group of observations.

Comments

Normally, an observation will have either a single value or a set of related observations. A few observations (e.g. Apgar score) may have both a value and related observations (for an Apgar score, the observations from which the measure is derived). If a value is present, the datatype for this element should be determined by Observation.code. This element has a variable name depending on the type as follows: valueQuantity, valueCodeableConcept, valueString, valueBoolean, valueRange, valueRatio, valueSampledData, valueAttachment, valueTime, valueDateTime, or valuePeriod. (The name format is "'value' + the type name" with a capital on the first letter of the type).

If the data element is usually coded or if the type associated with the Observation.value defines a coded value, use CodeableConcept instead of string datatype even if the value is uncoded text. A value set is bound to the ValueCodeableConcept element. For further discussion and examples see the notes section below.

103. Observation.dataAbsentReason
Definition

Provides a reason why the expected value in the element Observation.value[x] is missing.

Control0..0 This element is affected by the following invariants: obs-6
BindingThe codes SHALL be taken from Observation Value Absent Reason
TypeCodeableConcept
Must Supporttrue
Requirements

For many results it is necessary to handle exceptional values in measurements.

Comments

Null or exceptional values can be represented two ways in FHIR Observations. One way is to simply include them in the value set and represent the exceptions in the value. For example, measurement values for a serology test could be "detected", "not detected", "inconclusive", or "specimen unsatisfactory". The alternate way is to use the value element for actual observations and use the explicit dataAbsentReason element to record exceptional values. For example, the dataAbsentReason code "error" could be used when the measurement was not completed. Note that an observation may only be reported if there are values to report. For example differential cell counts values may be reported only when > 0. Because of these options, use-case agreements are required to interpret general observations for null or exceptional values.

104. Observation.interpretation
Definition

The assessment made based on the result of the observation. Intended as a simple compact code often placed adjacent to the result value in reports and flow sheets to signal the meaning/normalcy status of the result. Otherwise known as abnormal flag.

Control0..0
BindingThe codes SHALL be taken from Observation Interpretation Codes
TypeCodeableConcept
Must Supporttrue
Requirements

For some results, particularly numeric results, an interpretation is necessary to fully understand the significance of a result.

Alternate NamesAbnormal Flag
105. Observation.comment
Definition

May include statements about significant, unexpected or unreliable values, or information about the source of the value where this may be relevant to the interpretation of the result.

Control0..1
Typestring
Must Supporttrue
Requirements

Need to be able to provide free text additional information.

106. Observation.bodySite
Definition

Indicates the site on the subject's body where the observation was made (i.e. the target site).

Control0..0
BindingThe codes SHALL be taken from SNOMED CT Body Structures
TypeCodeableConcept
Must Supporttrue
Comments

Only used if not implicit in code found in Observation.code. In many systems, this may be represented as a related observation instead of an inline component. If the use case requires BodySite to be handled as a separate resource (e.g. to identify and track separately) then use the standard extension body-site-instance.

107. Observation.method
Definition

Indicates the mechanism used to perform the observation.

Control0..1
BindingThe codes SHOULD be taken from Observation Methods
TypeCodeableConcept
Requirements

In some cases, method can impact results and is thus used for determining whether results can be compared or determining significance of results.

Comments

Only used if not implicit in code for Observation.code.

108. Observation.method.id
Definition

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

Control0..1
Typestring
XML RepresentationIn the XML format, this property is represented as an attribute.
109. Observation.method.extension
Definition

May be used to represent additional information that is not part of the basic definition of the element. In order to make the use of extensions safe and manageable, 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.

Control0..*
TypeExtension
Alternate Namesextensions, user content
Comments

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

SlicingThis element introduces a set of slices on Observation.method.extension. The slices are unordered and Open, and can be differentiated using the following discriminators:
  • value @ url
110. Observation.method.coding
Definition

A reference to a code defined by a terminology system.

Control0..*
TypeCoding
Summarytrue
Requirements

Allows for translations and alternate encodings within a code system. Also supports communication of the same instance to systems requiring different encodings.

Comments

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.

SlicingThis element introduces a set of slices on Observation.method.coding. The slices are unordered and Open, and can be differentiated using the following discriminators:
  • value @ system
111. Observation.method.coding.id
Definition

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

Control0..1
Typestring
XML RepresentationIn the XML format, this property is represented as an attribute.
112. Observation.method.coding.extension
Definition

May be used to represent additional information that is not part of the basic definition of the element. In order to make the use of extensions safe and manageable, 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.

Control0..*
TypeExtension
Alternate Namesextensions, user content
Comments

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

SlicingThis element introduces a set of slices on Observation.method.coding.extension. The slices are unordered and Open, and can be differentiated using the following discriminators:
  • value @ url
113. Observation.method.coding.system
Definition

The identification of the code system that defines the meaning of the symbol in the code.

Control1..1
Typeuri
Summarytrue
Requirements

Need to be unambiguous about the source of the definition of the symbol.

Comments

The URI may be an OID (urn:oid:...) or a UUID (urn:uuid:...). OIDs and UUIDs SHALL be references to the HL7 OID registry. Otherwise, the URI should come from HL7's list of FHIR defined special URIs or it should de-reference to some definition that establish the system clearly and unambiguously.

114. Observation.method.coding.version
Definition

The version of the code system which was used when choosing this code. Note that a well-maintained code system does not need the version reported, because the meaning of codes is consistent across versions. However this cannot consistently be assured. and when the meaning is not guaranteed to be consistent, the version SHOULD be exchanged.

NoteThis is a business versionId, not a resource version id (see discussion)
Control0..1
Typestring
Summarytrue
Comments

Where the terminology does not clearly define what string should be used to identify code system versions, the recommendation is to use the date (expressed in FHIR date format) on which that version was officially published as the version date.

115. Observation.method.coding.code
Definition

A symbol in syntax defined by the system. The symbol may be a predefined code or an expression in a syntax defined by the coding system (e.g. post-coordination).

Control1..1
Typecode
Summarytrue
Requirements

Need to refer to a particular code in the system.

116. Observation.method.coding.display
Definition

A representation of the meaning of the code in the system, following the rules of the system.

Control1..1
Typestring
Summarytrue
Requirements

Need to be able to carry a human-readable meaning of the code for readers that do not know the system.

117. Observation.method.coding.userSelected
Definition

Indicates that this coding was chosen by a user directly - i.e. off a pick list of available items (codes or displays).

Control0..1
Typeboolean
Summarytrue
Requirements

This has been identified as a clinical safety criterium - that this exact system/code pair was chosen explicitly, rather than inferred by the system based on some rules or language processing.

Comments

Amongst a set of alternatives, a directly chosen code is the most appropriate starting point for new translations. There is some ambiguity about what exactly 'directly chosen' implies, and trading partner agreement may be needed to clarify the use of this element and its consequences more completely.

118. Observation.method.coding:snomedCT
SliceNamesnomedCT
Definition

A reference to a code defined by a terminology system.

Control0..1
TypeCoding
Summarytrue
Requirements

Allows for translations and alternate encodings within a code system. Also supports communication of the same instance to systems requiring different encodings.

Comments

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.

119. Observation.method.coding:snomedCT.id
Definition

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

Control0..1
Typestring
XML RepresentationIn the XML format, this property is represented as an attribute.
120. Observation.method.coding:snomedCT.extension
Definition

An Extension

Control0..*
TypeExtension
SlicingThis element introduces a set of slices on Observation.method.coding.extension. The slices are unordered and Open, and can be differentiated using the following discriminators:
  • value @ url
121. Observation.method.coding:snomedCT.extension:snomedCTDescriptionID
SliceNamesnomedCTDescriptionID
Definition

The SNOMED CT Description ID for the display.

Control0..*
TypeExtension(Extension-coding-sctdescid) (Complex Extension)
122. Observation.method.coding:snomedCT.system
Definition

The identification of the code system that defines the meaning of the symbol in the code.

Control1..1
Typeuri
Summarytrue
Requirements

Need to be unambiguous about the source of the definition of the symbol.

Comments

The URI may be an OID (urn:oid:...) or a UUID (urn:uuid:...). OIDs and UUIDs SHALL be references to the HL7 OID registry. Otherwise, the URI should come from HL7's list of FHIR defined special URIs or it should de-reference to some definition that establish the system clearly and unambiguously.

Fixed Valuehttp://snomed.info/sct
123. Observation.method.coding:snomedCT.version
Definition

The version of the code system which was used when choosing this code. Note that a well-maintained code system does not need the version reported, because the meaning of codes is consistent across versions. However this cannot consistently be assured. and when the meaning is not guaranteed to be consistent, the version SHOULD be exchanged.

NoteThis is a business versionId, not a resource version id (see discussion)
Control0..0
Typestring
Summarytrue
Comments

Where the terminology does not clearly define what string should be used to identify code system versions, the recommendation is to use the date (expressed in FHIR date format) on which that version was officially published as the version date.

124. Observation.method.coding:snomedCT.code
Definition

A symbol in syntax defined by the system. The symbol may be a predefined code or an expression in a syntax defined by the coding system (e.g. post-coordination).

Control1..1
Typecode
Summarytrue
Requirements

Need to refer to a particular code in the system.

125. Observation.method.coding:snomedCT.display
Definition

A representation of the meaning of the code in the system, following the rules of the system.

Control1..1
Typestring
Summarytrue
Requirements

Need to be able to carry a human-readable meaning of the code for readers that do not know the system.

126. Observation.method.coding:snomedCT.userSelected
Definition

Indicates that this coding was chosen by a user directly - i.e. off a pick list of available items (codes or displays).

Control0..1
Typeboolean
Summarytrue
Requirements

This has been identified as a clinical safety criterium - that this exact system/code pair was chosen explicitly, rather than inferred by the system based on some rules or language processing.

Comments

Amongst a set of alternatives, a directly chosen code is the most appropriate starting point for new translations. There is some ambiguity about what exactly 'directly chosen' implies, and trading partner agreement may be needed to clarify the use of this element and its consequences more completely.

127. Observation.method.text
Definition

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.

Control0..1
Typestring
Summarytrue
Requirements

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.

Comments

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

128. Observation.specimen
Definition

The specimen that was used when this observation was made.

Control0..0
TypeReference(CareConnect-Specimen-1)
Comments

Should only be used if not implicit in code found in Observation.code. Observations are not made on specimens themselves; they are made on a subject, but in many cases by the means of a specimen. Note that although specimens are often involved, they are not always tracked and reported explicitly. Also note that observation resources may be used in contexts that track the specimen explicitly (e.g. Diagnostic Report).

129. Observation.device
Definition

The device used to generate the observation data.

Control0..1
TypeReference(Device)
Comments

An extension should be used if further typing of the device is needed. Devices used to support obtaining an observation can be represented using either an extension or through the Observation.related element.

130. Observation.device.id
Definition

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

Control0..1
Typestring
XML RepresentationIn the XML format, this property is represented as an attribute.
131. Observation.device.extension
Definition

May be used to represent additional information that is not part of the basic definition of the element. In order to make the use of extensions safe and manageable, 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.

Control0..*
TypeExtension
Alternate Namesextensions, user content
Comments

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

SlicingThis element introduces a set of slices on Observation.device.extension. The slices are unordered and Open, and can be differentiated using the following discriminators:
  • value @ url
132. Observation.device.reference
Definition

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.

Control1..1 This element is affected by the following invariants: ref-1
Typestring
Summarytrue
Comments

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.

133. Observation.device.identifier
Definition

An identifier for the other resource. This is used when there is no way to reference the other resource directly, either because the entity 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.

NoteThis is a business identifier, not a resource identifier (see discussion)
Control0..1
TypeIdentifier
Summarytrue
Comments

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.

134. Observation.device.display
Definition

Plain text narrative that identifies the resource in addition to the resource reference.

Control0..1
Typestring
Summarytrue
Comments

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.

135. Observation.referenceRange
Definition

Guidance on how to interpret the value by comparison to a normal or recommended range.

Control0..0
TypeBackboneElement
Must Supporttrue
Requirements

Knowing what values are considered "normal" can help evaluate the significance of a particular result. Need to be able to provide multiple reference ranges for different contexts.

Comments

Most observations only have one generic reference range. Systems MAY choose to restrict to only supplying the relevant reference range based on knowledge about the patient (e.g., specific to the patient's age, gender, weight and other factors), but this may not be possible or appropriate. Whenever more than one reference range is supplied, the differences between them SHOULD be provided in the reference range and/or age properties.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() | (children().count() > id.count()))
obs-3: Must have at least a low or a high or text (: low.exists() or high.exists() or text.exists())
136. Observation.related
Definition

A reference to another resource (usually another Observation) whose relationship is defined by the relationship type code.

Control0..*
TypeBackboneElement
Must Supporttrue
Summarytrue
Requirements

Normally, an observation will have either a value or a set of related observations. A few observations (e.g. Apgar score) may have both a value and a set of related observations or sometimes a QuestionnaireResponse from which the measure is derived.

Comments

For a discussion on the ways Observations can assembled in groups together see Notes below.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() | (children().count() > id.count()))
137. Observation.related.id
Definition

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

Control0..1
Typestring
XML RepresentationIn the XML format, this property is represented as an attribute.
138. Observation.related.extension
Definition

May be used to represent additional information that is not part of the basic definition of the element. In order to make the use of extensions safe and manageable, 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.

Control0..*
TypeExtension
Alternate Namesextensions, user content
Comments

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

139. Observation.related.modifierExtension
Definition

May be used to represent additional information that is not part of the basic definition of the element, and that modifies the understanding of the element that contains it. Usually modifier elements provide negation or qualification. In order to make the use of extensions safe and manageable, 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.

Control0..*
TypeExtension
Is Modifiertrue
Summarytrue
Alternate Namesextensions, user content, modifiers
Comments

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

140. Observation.related.type
Definition

A code specifying the kind of relationship that exists with the target resource.

Control1..1
BindingThe codes SHALL be taken from ObservationRelationshipType Codes specifying how two observations are related
Typecode
Must Supporttrue
Requirements

A relationship type SHOULD be provided.

Comments

The "derived-from" type is the only logical choice when referencing the QuestionnaireAnswer resource.

Fixed Valuederived-from
141. Observation.related.target
Definition

A reference to the observation or QuestionnaireResponse resource that is related to this observation.

Control1..1
TypeReference(CareConnect-Observation-1)
Must Supporttrue
142. Observation.component
Definition

Some observations have multiple component observations. These component observations are expressed as separate code value pairs that share the same attributes. Examples include systolic and diastolic component observations for blood pressure measurement and multiple component observations for genetics observations.

Control0..0
TypeBackboneElement
Must Supporttrue
Summarytrue
Requirements

Component observations share the same attributes in the Observation resource as the primary observation and are always treated a part of a single observation (they are not separable). However, the reference range for the primary observation value is not inherited by the component values and is required when appropriate for each component observation.

Comments

For a discussion on the ways Observations can be assembled in groups together see Notes below.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() | (children().count() > id.count()))