FHIR New Zealand Patient Summary IG
0.3.0 - ci-build New Zealand flag

FHIR New Zealand Patient Summary IG - Local Development build (v0.3.0) built by the FHIR (HL7® FHIR® Standard) Build Tools. See the Directory of published versions

Resource Profile: NZPSObservationPregnancyEDD - Detailed Descriptions

Active as of 2024-08-01

Definitions for the nzps-observation-pregnancy-edd resource profile.

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

0. Observation
2. Observation.subject
TypeReference(NZPS-Patient)

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

0. Observation
Definition

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

ShortMeasurements and simple assertions
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 laboratory reports, etc.

Control0..*
Is Modifierfalse
Summaryfalse
Alternate NamesVital Signs, Measurement, Results, Tests
Invariantsdom-2: If the resource is contained in another resource, it SHALL NOT contain nested Resources (contained.contained.empty())
dom-3: If the resource is contained in another resource, it SHALL be referred to from elsewhere in the resource or SHALL refer to the containing resource (contained.where((('#'+id in (%resource.descendants().reference | %resource.descendants().as(canonical) | %resource.descendants().as(uri) | %resource.descendants().as(url))) or descendants().where(reference = '#').exists() or descendants().where(as(canonical) = '#').exists() or descendants().where(as(canonical) = '#').exists()).not()).trace('unmatched', id).empty())
dom-4: If a resource is contained in another resource, it SHALL NOT have a meta.versionId or a meta.lastUpdated (contained.meta.versionId.empty() and contained.meta.lastUpdated.empty())
dom-5: If a resource is contained in another resource, it SHALL NOT have a security label (contained.meta.security.empty())
dom-6: A resource should have narrative for robust management (text.`div`.exists())
obs-6: dataAbsentReason SHALL only be present if Observation.value[x] is not present (dataAbsentReason.empty() or value.empty())
obs-7: If Observation.code is the same as an Observation.component.code then the value element associated with the code SHALL NOT be present (value.empty() or component.code.where(coding.intersect(%resource.code.coding).exists()).empty())
obs-6: dataAbsentReason SHALL only be present if Observation.value[x] is not present (dataAbsentReason.empty() or value.empty())
obs-7: If Observation.code is the same as an Observation.component.code then the value element associated with the code SHALL NOT be present (value.empty() or component.code.where(coding.intersect(%resource.code.coding).exists()).empty())
2. 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. Often, this is a reference to an implementation guide that defines the special rules along with other profiles etc.

ShortA set of rules under which this content was created
Comments

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

Control0..1
Typeuri
Is Modifiertrue because This element is labeled as a modifier because the implicit rules may provide additional knowledge about the resource that modifies it's meaning or interpretation
Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
Summarytrue
Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
4. 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 and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. To make the use of extensions safe and 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.

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

ShortExtensions that cannot be ignored
Comments

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

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

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

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

The status of the result value.

Shortregistered | preliminary | final | amended +
Comments

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

Control1..1
BindingThe codes SHALL be taken from ObservationStatushttp://hl7.org/fhir/ValueSet/observation-status|4.0.1
(required to http://hl7.org/fhir/ValueSet/observation-status|4.0.1)

Codes providing the status of an observation.

Typecode
Is Modifiertrue because This element is labeled as a modifier because it is a status element that contains status entered-in-error which means that the resource should not be treated as valid
Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
Summarytrue
Requirements

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

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

A concept that may be defined by a formal reference to a terminology or ontology or may be provided by text.


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

ShortConcept - reference to a terminology or just textType of observation (code / type)
Comments

Not all terminology uses fit this general pattern. In some cases, models should not use CodeableConcept and use Coding directly and provide their own structure for managing text, codings, translations and the relationship between elements and pre- and post-coordination.


All code-value and, if present, component.code-component.value pairs need to be taken into account to correctly understand the meaning of the observation.

Control1..1
This element is affected by the following invariants: ele-1
BindingThe codes SHALL be taken from For example codes, see Pregnancy Expected Delivery Date Method - IPShttp://hl7.org/fhir/ValueSet/observation-codes
(required to http://hl7.org/fhir/uv/ips/ValueSet/edd-method-uv-ips)
TypeCodeableConcept(Codeable Concept (IPS))
Is Modifierfalse
Must Supporttrue
Requirements

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

Alternate NamesName
Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
10. Observation.subject
Definition

The patient, or group of patients, location, or device this observation is about and into whose record the observation is placed. If the actual focus of the observation is different from the subject (or a sample of, part, or region of the subject), the focus element or the code itself specifies the actual focus of the observation.

ShortWho and/or what the observation is 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.

Control10..1
TypeReference(NZPS-Patient, Patient, Group, Device, Location)
Is Modifierfalse
Must Supporttrue
Summarytrue
Requirements

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

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

ShortLiteral reference, Relative, internal or absolute URL
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.

Control10..1
This element is affected by the following invariants: ref-1
Typestring
Is Modifierfalse
Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
Must Supporttrue
Summarytrue
Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
14. 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.

ShortClinically relevant time/time-period for observation
Comments

At least a date should be present unless this observation is a historical report. For recording imprecise or "fuzzy" times (For example, a blood glucose measurement taken "after breakfast") use the Timing datatype which allow the measurement to be tied to regular life events.

Control10..1
TypedateTime, Period, Timing, instant
[x] NoteSeeChoice of Data Typesfor further information about how to use [x]
Is Modifierfalse
Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
Must Supporttrue
Summarytrue
Requirements

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

Alternate NamesOccurrence
Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
16. Observation.effective[x].extension:data-absent-reason
Slice Namedata-absent-reason
Definition

Provides a reason why the effectiveTime is missing.

Shorteffective[x] absence reason
Control0..1
This element is affected by the following invariants: ele-1
TypeExtension(Data Absent Reason) (Extension Type: code)
Is Modifierfalse
Must Supporttrue
Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
18. Observation.value[x]
Definition

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

ShortActual result
Comments

An observation may have; 1) a single value here, 2) both a value and a set of related or component values, or 3) only a set of related or component values. If a value is present, the datatype for this element should be determined by Observation.code. A CodeableConcept with just a text would be used instead of a string if the field was usually coded, or if the type associated with the Observation.code defines a coded value. For additional guidance, see the Notes section below.

Control0..1
This element is affected by the following invariants: obs-7
TypeChoice of: Quantity, CodeableConcept, string, boolean, integer, Range, Ratio, SampledData, time, dateTime, Period
[x] NoteSeeChoice of Data Typesfor further information about how to use [x]
Is Modifierfalse
Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
Summarytrue
Requirements

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

Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
SlicingThis element introduces a set of slices on Observation.value[x]. The slices areUnordered and Open, and can be differentiated using the following discriminators:
  • type @ $this
  • 20. Observation.value[x]:valueDateTime
    Slice NamevalueDateTime
    Definition

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

    ShortActual result
    Comments

    An observation may have; 1) a single value here, 2) both a value and a set of related or component values, or 3) only a set of related or component values. If a value is present, the datatype for this element should be determined by Observation.code. A CodeableConcept with just a text would be used instead of a string if the field was usually coded, or if the type associated with the Observation.code defines a coded value. For additional guidance, see the Notes section below.

    Control0..1
    This element is affected by the following invariants: obs-7
    TypedateTime, boolean, string, SampledData, Quantity, Period, Ratio, integer, time, Range, CodeableConcept
    [x] NoteSeeChoice of Data Typesfor further information about how to use [x]
    Is Modifierfalse
    Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
    Must Supporttrue
    Summarytrue
    Requirements

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

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

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

    ShortObserved body part
    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 bodySite.

    Control0..01
    BindingFor example codes, see SNOMEDCTBodyStructureshttp://hl7.org/fhir/ValueSet/body-site
    (example to http://hl7.org/fhir/ValueSet/body-site)

    Codes describing anatomical locations. May include laterality.

    TypeCodeableConcept
    Is Modifierfalse
    Must Supportfalse
    Summaryfalse
    Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
    24. Observation.method
    Definition

    Indicates the mechanism used to perform the observation.

    ShortHow it was done
    Comments

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

    Control0..01
    BindingFor example codes, see ObservationMethodshttp://hl7.org/fhir/ValueSet/observation-methods
    (example to http://hl7.org/fhir/ValueSet/observation-methods)

    Methods for simple observations.

    TypeCodeableConcept
    Is Modifierfalse
    Must Supportfalse
    Summaryfalse
    Requirements

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

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

    The specimen that was used when this observation was made.

    ShortSpecimen used for this observation
    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).

    Control0..01
    TypeReference(Specimen)
    Is Modifierfalse
    Must Supportfalse
    Summaryfalse
    Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
    28. Observation.device
    Definition

    The device used to generate the observation data.

    Short(Measurement) Device
    Comments

    Note that this is not meant to represent a device involved in the transmission of the result, e.g., a gateway. Such devices may be documented using the Provenance resource where relevant.

    Control0..01
    TypeReference(Device, DeviceMetric)
    Is Modifierfalse
    Must Supportfalse
    Summaryfalse
    Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
    30. Observation.referenceRange
    Definition

    Guidance on how to interpret the value by comparison to a normal or recommended range. Multiple reference ranges are interpreted as an "OR". In other words, to represent two distinct target populations, two referenceRange elements would be used.

    ShortProvides guide for interpretation
    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 might 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.

    Control0..0*
    TypeBackboneElement
    Is Modifierfalse
    Must Supportfalse
    Summaryfalse
    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.

    Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (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())
    obs-3: Must have at least a low or a high or text (low.exists() or high.exists() or text.exists())
    33. 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.

    ShortComponent results
    Comments

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

    Control0..0*
    TypeBackboneElement
    Is Modifierfalse
    Must Supportfalse
    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.

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

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

    0. Observation
    Definition

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

    ShortMeasurements and simple assertions
    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 laboratory reports, etc.

    Control0..*
    Is Modifierfalse
    Summaryfalse
    Alternate NamesVital Signs, Measurement, Results, Tests
    Invariantsdom-2: If the resource is contained in another resource, it SHALL NOT contain nested Resources (contained.contained.empty())
    dom-3: If the resource is contained in another resource, it SHALL be referred to from elsewhere in the resource or SHALL refer to the containing resource (contained.where((('#'+id in (%resource.descendants().reference | %resource.descendants().as(canonical) | %resource.descendants().as(uri) | %resource.descendants().as(url))) or descendants().where(reference = '#').exists() or descendants().where(as(canonical) = '#').exists() or descendants().where(as(canonical) = '#').exists()).not()).trace('unmatched', id).empty())
    dom-4: If a resource is contained in another resource, it SHALL NOT have a meta.versionId or a meta.lastUpdated (contained.meta.versionId.empty() and contained.meta.lastUpdated.empty())
    dom-5: If a resource is contained in another resource, it SHALL NOT have a security label (contained.meta.security.empty())
    dom-6: A resource should have narrative for robust management (text.`div`.exists())
    obs-6: dataAbsentReason SHALL only be present if Observation.value[x] is not present (dataAbsentReason.empty() or value.empty())
    obs-7: If Observation.code is the same as an Observation.component.code then the value element associated with the code SHALL NOT be present (value.empty() or component.code.where(coding.intersect(%resource.code.coding).exists()).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.

    ShortLogical id of this artifact
    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.

    Control0..1
    Typeid
    Is Modifierfalse
    Summarytrue
    4. Observation.meta
    Definition

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

    ShortMetadata about the resource
    Control0..1
    TypeMeta
    Is Modifierfalse
    Summarytrue
    Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
    6. 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. Often, this is a reference to an implementation guide that defines the special rules along with other profiles etc.

    ShortA set of rules under which this content was created
    Comments

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

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

    The base language in which the resource is written.

    ShortLanguage of the resource content
    Comments

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

    Control0..1
    BindingThe codes SHOULD be taken from CommonLanguages
    (preferred to http://hl7.org/fhir/ValueSet/languages)

    A human language.

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

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

    ShortText summary of the resource, for human interpretation
    Comments

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

    Control0..1
    TypeNarrative
    Is Modifierfalse
    Summaryfalse
    Alternate Namesnarrative, html, xhtml, display
    Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
    12. 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.

    ShortContained, inline Resources
    Comments

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

    Control0..*
    TypeResource
    Is Modifierfalse
    Summaryfalse
    Alternate Namesinline resources, anonymous resources, contained resources
    14. Observation.extension
    Definition

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

    ShortAdditional content defined by implementations
    Comments

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

    Control0..*
    TypeExtension
    Is Modifierfalse
    Summaryfalse
    Alternate Namesextensions, user content
    Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
    ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
    16. 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 and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. To make the use of extensions safe and 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.

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

    ShortExtensions that cannot be ignored
    Comments

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

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

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

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

    A unique identifier assigned to this observation.

    ShortBusiness Identifier for observation
    NoteThis is a business identifier, not a resource identifier (see discussion)
    Control0..*
    TypeIdentifier
    Is Modifierfalse
    Summarytrue
    Requirements

    Allows observations to be distinguished and referenced.

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

    A plan, proposal or order that is fulfilled in whole or in part by this event. For example, a MedicationRequest may require a patient to have laboratory test performed before it is dispensed.

    ShortFulfills plan, proposal or order
    Control0..*
    TypeReference(CarePlan, DeviceRequest, ImmunizationRecommendation, MedicationRequest, NutritionOrder, ServiceRequest)
    Is Modifierfalse
    Summarytrue
    Requirements

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

    Alternate NamesFulfills
    Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
    22. Observation.partOf
    Definition

    A larger event of which this particular Observation is a component or step. For example, an observation as part of a procedure.

    ShortPart of referenced event
    Comments

    To link an Observation to an Encounter use encounter. See the Notes below for guidance on referencing another Observation.

    Control0..*
    TypeReference(MedicationAdministration, MedicationDispense, MedicationStatement, Procedure, Immunization, ImagingStudy)
    Is Modifierfalse
    Summarytrue
    Alternate NamesContainer
    Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
    24. Observation.status
    Definition

    The status of the result value.

    Shortregistered | preliminary | final | amended +
    Comments

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

    Control1..1
    BindingThe codes SHALL be taken from ObservationStatus
    (required to http://hl7.org/fhir/ValueSet/observation-status|4.0.1)

    Codes providing the status of an observation.

    Typecode
    Is Modifiertrue because This element is labeled as a modifier because it is a status element that contains status entered-in-error which means that the resource should not be treated as valid
    Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
    Summarytrue
    Requirements

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

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

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

    ShortClassification of type of observation
    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.

    Control0..*
    BindingThe codes SHOULD be taken from ObservationCategoryCodes
    (preferred to http://hl7.org/fhir/ValueSet/observation-category)

    Codes for high level observation categories.

    TypeCodeableConcept
    Is Modifierfalse
    Summaryfalse
    Requirements

    Used for filtering what observations are retrieved and displayed.

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

    A concept that may be defined by a formal reference to a terminology or ontology or may be provided by text.

    ShortConcept - reference to a terminology or just text
    Comments

    Not all terminology uses fit this general pattern. In some cases, models should not use CodeableConcept and use Coding directly and provide their own structure for managing text, codings, translations and the relationship between elements and pre- and post-coordination.

    Control1..1
    This element is affected by the following invariants: ele-1
    BindingThe codes SHALL be taken from Pregnancy Expected Delivery Date Method - IPS
    (required to http://hl7.org/fhir/uv/ips/ValueSet/edd-method-uv-ips)
    TypeCodeableConcept(Codeable Concept (IPS))
    Is Modifierfalse
    Must Supporttrue
    Requirements

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

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

    The patient, or group of patients, location, or device this observation is about and into whose record the observation is placed. If the actual focus of the observation is different from the subject (or a sample of, part, or region of the subject), the focus element or the code itself specifies the actual focus of the observation.

    ShortWho and/or what the observation is 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.

    Control1..1
    TypeReference(NZPS-Patient)
    Is Modifierfalse
    Must Supporttrue
    Summarytrue
    Requirements

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

    Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
    32. 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.

    ShortUnique id for inter-element referencing
    Control0..1
    Typestring
    Is Modifierfalse
    XML FormatIn the XML format, this property is represented as an attribute.
    Summaryfalse
    34. Observation.subject.extension
    Definition

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

    ShortAdditional content defined by implementations
    Comments

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

    Control0..*
    TypeExtension
    Is Modifierfalse
    Summaryfalse
    Alternate Namesextensions, user content
    Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
    ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
    SlicingThis element introduces a set of slices on Observation.subject.extension. The slices areUnordered and Open, and can be differentiated using the following discriminators:
    • value @ url
    • 36. 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.

      ShortLiteral reference, Relative, internal or absolute URL
      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.

      Control1..1
      This element is affected by the following invariants: ref-1
      Typestring
      Is Modifierfalse
      Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
      Must Supporttrue
      Summarytrue
      Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
      38. Observation.subject.type
      Definition

      The expected type of the target of the reference. If both Reference.type and Reference.reference are populated and Reference.reference is a FHIR URL, both SHALL be consistent.

      The type is the Canonical URL of Resource Definition that is the type this reference refers to. References are URLs that are relative to http://hl7.org/fhir/StructureDefinition/ e.g. "Patient" is a reference to http://hl7.org/fhir/StructureDefinition/Patient. Absolute URLs are only allowed for logical models (and can only be used in references in logical models, not resources).

      ShortType the reference refers to (e.g. "Patient")
      Comments

      This element is used to indicate the type of the target of the reference. This may be used which ever of the other elements are populated (or not). In some cases, the type of the target may be determined by inspection of the reference (e.g. a RESTful URL) or by resolving the target of the reference; if both the type and a reference is provided, the reference SHALL resolve to a resource of the same type as that specified.

      Control0..1
      BindingUnless not suitable, these codes SHALL be taken from ResourceType
      (extensible to http://hl7.org/fhir/ValueSet/resource-types)

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

      Typeuri
      Is Modifierfalse
      Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
      Summarytrue
      Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
      40. Observation.subject.identifier
      Definition

      An identifier for the target resource. This is used when there is no way to reference the other resource directly, either because the entity it represents is not available through a FHIR server, or because there is no way for the author of the resource to convert a known identifier to an actual location. There is no requirement that a Reference.identifier point to something that is actually exposed as a FHIR instance, but it SHALL point to a business concept that would be expected to be exposed as a FHIR instance, and that instance would need to be of a FHIR resource type allowed by the reference.

      ShortLogical reference, when literal reference is not known
      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.

      Reference is intended to point to a structure that can potentially be expressed as a FHIR resource, though there is no need for it to exist as an actual FHIR resource instance - except in as much as an application wishes to actual find the target of the reference. The content referred to be the identifier must meet the logical constraints implied by any limitations on what resource types are permitted for the reference. For example, it would not be legitimate to send the identifier for a drug prescription if the type were Reference(Observation|DiagnosticReport). One of the use-cases for Reference.identifier is the situation where no FHIR representation exists (where the type is Reference (Any).

      NoteThis is a business identifier, not a resource identifier (see discussion)
      Control0..1
      TypeIdentifier
      Is Modifierfalse
      Summarytrue
      Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
      42. Observation.subject.display
      Definition

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

      ShortText alternative for the resource
      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.

      Control0..1
      Typestring
      Is Modifierfalse
      Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
      Summarytrue
      Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
      44. Observation.focus
      Definition

      The actual focus of an observation when it is not the patient of record representing something or someone associated with the patient such as a spouse, parent, fetus, or donor. For example, fetus observations in a mother's record. The focus of an observation could also be an existing condition, an intervention, the subject's diet, another observation of the subject, or a body structure such as tumor or implanted device. An example use case would be using the Observation resource to capture whether the mother is trained to change her child's tracheostomy tube. In this example, the child is the patient of record and the mother is the focus.

      ShortWhat the observation is about, when it is not about the subject of record
      Comments

      Typically, an observation is made about the subject - a patient, or group of patients, location, or device - and the distinction between the subject and what is directly measured for an observation is specified in the observation code itself ( e.g., "Blood Glucose") and does not need to be represented separately using this element. Use specimen if a reference to a specimen is required. If a code is required instead of a resource use either bodysite for bodysites or the standard extension focusCode.

      Control0..*
      TypeReference(Resource)
      Is Modifierfalse
      Summarytrue
      Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
      46. Observation.encounter
      Definition

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

      ShortHealthcare event during which this observation is made
      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 but still be tied to the context of the encounter (e.g. pre-admission laboratory tests).

      Control0..1
      TypeReference(Encounter)
      Is Modifierfalse
      Summarytrue
      Requirements

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

      Alternate NamesContext
      Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
      48. 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.

      ShortClinically relevant time/time-period for observation
      Comments

      At least a date should be present unless this observation is a historical report. For recording imprecise or "fuzzy" times (For example, a blood glucose measurement taken "after breakfast") use the Timing datatype which allow the measurement to be tied to regular life events.

      Control1..1
      TypedateTime
      [x] NoteSeeChoice of Data Typesfor further information about how to use [x]
      Is Modifierfalse
      Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
      Must Supporttrue
      Summarytrue
      Requirements

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

      Alternate NamesOccurrence
      Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
      50. Observation.effective[x].id
      Definition

      unique id for the element within a resource (for internal references)

      Shortxml:id (or equivalent in JSON)
      Control0..1
      Typestring
      Is Modifierfalse
      XML FormatIn the XML format, this property is represented as an attribute.
      Summaryfalse
      52. Observation.effective[x].extension
      Definition

      An Extension

      ShortExtension
      Control0..*
      TypeExtension
      Is Modifierfalse
      Summaryfalse
      Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
      ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
      SlicingThis element introduces a set of slices on Observation.effective[x].extension. The slices areUnordered and Open, and can be differentiated using the following discriminators:
      • value @ url
      • 54. Observation.effective[x].extension:data-absent-reason
        Slice Namedata-absent-reason
        Definition

        Provides a reason why the effectiveTime is missing.

        Shorteffective[x] absence reason
        Control0..1
        This element is affected by the following invariants: ele-1
        TypeExtension(Data Absent Reason) (Extension Type: code)
        Is Modifierfalse
        Must Supporttrue
        Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
        ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
        56. Observation.effective[x].value
        Definition

        The actual value

        ShortPrimitive value for dateTime
        Control0..1
        TypedateTime
        Is Modifierfalse
        XML FormatIn the XML format, this property is represented as an attribute.
        Summaryfalse
        58. Observation.issued
        Definition

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

        ShortDate/Time this version was made available
        Comments

        For Observations that don’t require review and verification, it may be the same as the lastUpdated time of the resource itself. For Observations that do require review and verification for certain updates, it might not be the same as the lastUpdated time of the resource itself due to a non-clinically significant update that doesn’t require the new version to be reviewed and verified again.

        Control0..1
        Typeinstant
        Is Modifierfalse
        Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
        Summarytrue
        Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
        60. Observation.performer
        Definition

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

        ShortWho is responsible for the observation
        Control0..*
        TypeReference(Practitioner, PractitionerRole, Organization, CareTeam, Patient, RelatedPerson)
        Is Modifierfalse
        Summarytrue
        Requirements

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

        Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
        62. Observation.value[x]
        Definition

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

        ShortActual result
        Comments

        An observation may have; 1) a single value here, 2) both a value and a set of related or component values, or 3) only a set of related or component values. If a value is present, the datatype for this element should be determined by Observation.code. A CodeableConcept with just a text would be used instead of a string if the field was usually coded, or if the type associated with the Observation.code defines a coded value. For additional guidance, see the Notes section below.

        Control0..1
        This element is affected by the following invariants: obs-7
        TypeChoice of: Quantity, CodeableConcept, string, boolean, integer, Range, Ratio, SampledData, time, dateTime, Period
        [x] NoteSeeChoice of Data Typesfor further information about how to use [x]
        Is Modifierfalse
        Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
        Summarytrue
        Requirements

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

        Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
        SlicingThis element introduces a set of slices on Observation.value[x]. The slices areUnordered and Open, and can be differentiated using the following discriminators:
        • type @ $this
        • 64. Observation.value[x]:valueDateTime
          Slice NamevalueDateTime
          Definition

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

          ShortActual result
          Comments

          An observation may have; 1) a single value here, 2) both a value and a set of related or component values, or 3) only a set of related or component values. If a value is present, the datatype for this element should be determined by Observation.code. A CodeableConcept with just a text would be used instead of a string if the field was usually coded, or if the type associated with the Observation.code defines a coded value. For additional guidance, see the Notes section below.

          Control0..1
          This element is affected by the following invariants: obs-7
          TypedateTime
          [x] NoteSeeChoice of Data Typesfor further information about how to use [x]
          Is Modifierfalse
          Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
          Must Supporttrue
          Summarytrue
          Requirements

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

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

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

          ShortWhy the result is missing
          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.

          Control0..1
          This element is affected by the following invariants: obs-6
          BindingUnless not suitable, these codes SHALL be taken from DataAbsentReason
          (extensible to http://hl7.org/fhir/ValueSet/data-absent-reason)

          Codes specifying why the result (Observation.value[x]) is missing.

          TypeCodeableConcept
          Is Modifierfalse
          Summaryfalse
          Requirements

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

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

          A categorical assessment of an observation value. For example, high, low, normal.

          ShortHigh, low, normal, etc.
          Comments

          Historically used for laboratory results (known as 'abnormal flag' ), its use extends to other use cases where coded interpretations are relevant. Often reported as one or more simple compact codes this element is often placed adjacent to the result value in reports and flow sheets to signal the meaning/normalcy status of the result.

          Control0..*
          BindingUnless not suitable, these codes SHALL be taken from ObservationInterpretationCodes
          (extensible to http://hl7.org/fhir/ValueSet/observation-interpretation)

          Codes identifying interpretations of observations.

          TypeCodeableConcept
          Is Modifierfalse
          Summaryfalse
          Requirements

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

          Alternate NamesAbnormal Flag
          Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
          70. Observation.note
          Definition

          Comments about the observation or the results.

          ShortComments about the observation
          Comments

          May include general statements about the observation, or statements about significant, unexpected or unreliable results values, or information about its source when relevant to its interpretation.

          Control0..*
          TypeAnnotation
          Is Modifierfalse
          Summaryfalse
          Requirements

          Need to be able to provide free text additional information.

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

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

          ShortObserved body part
          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 bodySite.

          Control0..0
          BindingFor example codes, see SNOMEDCTBodyStructures
          (example to http://hl7.org/fhir/ValueSet/body-site)

          Codes describing anatomical locations. May include laterality.

          TypeCodeableConcept
          Is Modifierfalse
          Must Supportfalse
          Summaryfalse
          Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
          74. Observation.method
          Definition

          Indicates the mechanism used to perform the observation.

          ShortHow it was done
          Comments

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

          Control0..0
          BindingFor example codes, see ObservationMethods
          (example to http://hl7.org/fhir/ValueSet/observation-methods)

          Methods for simple observations.

          TypeCodeableConcept
          Is Modifierfalse
          Must Supportfalse
          Summaryfalse
          Requirements

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

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

          The specimen that was used when this observation was made.

          ShortSpecimen used for this observation
          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).

          Control0..0
          TypeReference(Specimen)
          Is Modifierfalse
          Must Supportfalse
          Summaryfalse
          Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
          78. Observation.device
          Definition

          The device used to generate the observation data.

          Short(Measurement) Device
          Comments

          Note that this is not meant to represent a device involved in the transmission of the result, e.g., a gateway. Such devices may be documented using the Provenance resource where relevant.

          Control0..0
          TypeReference(Device, DeviceMetric)
          Is Modifierfalse
          Must Supportfalse
          Summaryfalse
          Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
          80. Observation.referenceRange
          Definition

          Guidance on how to interpret the value by comparison to a normal or recommended range. Multiple reference ranges are interpreted as an "OR". In other words, to represent two distinct target populations, two referenceRange elements would be used.

          ShortProvides guide for interpretation
          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 might 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.

          Control0..0
          TypeBackboneElement
          Is Modifierfalse
          Must Supportfalse
          Summaryfalse
          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.

          Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (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())
          91. Observation.hasMember
          Definition

          This observation is a group observation (e.g. a battery, a panel of tests, a set of vital sign measurements) that includes the target as a member of the group.

          ShortRelated resource that belongs to the Observation group
          Comments

          When using this element, an observation will typically have either a value or a set of related resources, although both may be present in some cases. For a discussion on the ways Observations can assembled in groups together, see Notes below. Note that a system may calculate results from QuestionnaireResponse into a final score and represent the score as an Observation.

          Control0..*
          TypeReference(Observation, QuestionnaireResponse, MolecularSequence)
          Is Modifierfalse
          Summarytrue
          Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
          93. Observation.derivedFrom
          Definition

          The target resource that represents a measurement from which this observation value is derived. For example, a calculated anion gap or a fetal measurement based on an ultrasound image.

          ShortRelated measurements the observation is made from
          Comments

          All the reference choices that are listed in this element can represent clinical observations and other measurements that may be the source for a derived value. The most common reference will be another Observation. For a discussion on the ways Observations can assembled in groups together, see Notes below.

          Control0..*
          TypeReference(DocumentReference, ImagingStudy, Media, QuestionnaireResponse, Observation, MolecularSequence)
          Is Modifierfalse
          Summarytrue
          Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
          95. 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.

          ShortComponent results
          Comments

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

          Control0..0
          TypeBackboneElement
          Is Modifierfalse
          Must Supportfalse
          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.

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