PrescribeIT® Specification and Guide Version 5.0


v5.0 of this specification has been superseded by v5.3. v5.3 is compatible but adds additional features for Quebec.

The version (Bundle.meta.tag:version) that is sent in the message will remain PrescribeIT5.0

 

Definitions for the profile-observation-rx Profile.

1. Observation
Definition

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

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

At present, only supported observations are height and weight.

Max Length0
InvariantsDefined on this element
obs-6: dataAbsentReason SHALL only be present if Observation.value[x] is not present (: dataAbsentReason.empty() or value.empty())
obs-7: Component code SHALL not be same as observation code (: value.empty() or code!=component.code)
2. Observation.id
Definition

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

Control1..1
Typeid
Must Supporttrue
Comments

Usage Note: This will usually be a GUID and is assigned by the sending application. Ideally it should be consistent for all messages referencing this observation measurement.

Max Length0
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
Max Length0
4. 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
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 as much as possible.

Max Length0
5. Observation.language
Definition

The base language in which the resource is written.

Control0..1
BindingThe codes SHALL be taken from http://tools.ietf.org/html/bcp47 A human language.

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).

Max Length0
6. 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.

Max Length0
7. 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.

Max Length0
8. Observation.extension
Definition

May be used to represent additional information that is not part of the basic definition of the resource. 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.

Max Length0
9. 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.

Max Length0
10. Observation.identifier
Definition

A unique identifier for the simple observation instance.

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

Allows observations to be distinguished and referenced.

Max Length0
11. Observation.status
Definition

The status of the result value.

Control1..1
BindingThe codes SHALL be taken from ObservationStatus Codes providing the status of an observation.

Typecode
Is Modifiertrue
Must Supporttrue
Requirements

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

Comments

Fixed value: final

Max Length0
Fixed Valuefinal
12. Observation.category
Definition

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

Control1..1
BindingFor example codes, see Observation Category Codes Codes for high level observation categories .

TypeCodeableConcept(Shared Health CodeableConcept Code)
Must Supporttrue
Comments

codes are from HL7 and system URL is http://hl7.org/fhir/observation-category.

Max Length0
13. Observation.category.id
Definition

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

Control0..1
Typeid
Max Length0
14. 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.

Max Length0
15. Observation.category.coding
Definition

A reference to a code defined by a terminology system.

Control1..*
TypeCoding
Must Supporttrue
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 labelled as UserSelected = true.

Max Length0
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
16. Observation.category.coding.id
Definition

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

Control0..1
Typeid
Max Length0
17. Observation.category.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.

Max Length0
18. Observation.category.coding.system
Definition

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

Control1..1
Typeuri
Must Supporttrue
Requirements

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

Comments

This is the URI that represents the coding system as defined within the binding.

Max Length0
19. Observation.category.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
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.

Max Length0
20. Observation.category.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
Must Supporttrue
Requirements

Need to refer to a particular code in the system.

Comments

This is the code as defined within the binding.

Max Length0
21. Observation.category.coding.display
Definition

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

Control0..1
Typestring
Requirements

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

Max Length0
22. Observation.category.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
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.

Max Length0
23. Observation.category.coding:HL7Code
SliceNameHL7Code
Definition

A reference to a code defined by a terminology system.

Control1..*
TypeCoding
Must Supporttrue
Requirements

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

Comments

See children for fixed value

Max Length0
24. Observation.category.coding:HL7Code.id
Definition

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

Control0..1
Typeid
Max Length0
25. Observation.category.coding:HL7Code.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.

Max Length0
26. Observation.category.coding:HL7Code.system
Definition

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

Control1..1
Typeuri
Must Supporttrue
Requirements

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

Comments

Fixed value: http://hl7.org/fhir/observation-category

Max Length0
Fixed Valuehttp://hl7.org/fhir/observation-category
27. Observation.category.coding:HL7Code.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
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.

Max Length0
28. Observation.category.coding:HL7Code.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
Requirements

Need to refer to a particular code in the system.

Comments

Fixed value: vital-signs

Max Length0
Fixed Valuevital-signs
29. Observation.category.coding:HL7Code.display
Definition

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

Control0..1
Typestring
Requirements

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

Max Length0
30. Observation.category.coding:HL7Code.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
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.

Max Length0
31. 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
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.

Max Length0
32. Observation.code
Definition

Identification of the type of measurement/observation that was made about the patient. The only two allowable types are height and weight.

Control1..1
BindingThe codes SHALL be taken from PrescriptionObservationTypeVitalSign (20170626) Pharmacy-related vital signs

TypeCodeableConcept(Shared Health CodeableConcept Code)
Must Supporttrue
Requirements

Distinguishes what kind of information is being specified. Code is mandatory to ensure that measurements/observations are distinguishable

Comments

-

Max Length0
33. Observation.code.id
Definition

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

Control0..1
Typeid
Max Length0
34. 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.

Max Length0
35. Observation.code.coding
Definition

A reference to a code defined by a terminology system.

Control1..*
TypeCoding
Must Supporttrue
Requirements

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

Comments

Code and System will be set. For Body height code value = 8302-2 For Body weight code value = 29463-7

Max Length0
36. Observation.code.coding.id
Definition

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

Control0..1
Typeid
Max Length0
37. Observation.code.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.

Max Length0
38. Observation.code.coding.system
Definition

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

Control1..1
Typeuri
Must Supporttrue
Requirements

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

Comments

This is the URI that represents the coding system as defined within the binding.

Max Length0
39. Observation.code.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
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.

Max Length0
40. Observation.code.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
Must Supporttrue
Requirements

Need to refer to a particular code in the system.

Comments

This is the code as defined within the binding.

Max Length0
41. Observation.code.coding.display
Definition

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

Control0..1
Typestring
Requirements

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

Max Length0
42. Observation.code.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
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.

Max Length0
43. 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
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.

Max Length0
44. Observation.subject
Definition

A reference from one resource to another.

Control1..1
TypeReference(Shared Health Reference)(Shared Health Patient)
Must Supporttrue
Requirements

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

Comments

This must point to the patient associated with the message

Max Length0
45. Observation.encounter
Definition

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

Control0..1
TypeReference(Encounter)
Requirements

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

Max Length0
46. 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.

Control0..1
TypedateTime
[x] NoteSee Choice of Data Types for further information about how to use [x]
Requirements

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

Comments

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

Max Length0
SlicingThis element introduces a set of slices on Observation.effective[x]. The slices are unordered and Closed, and can be differentiated using the following discriminators:
  • type @ $this
47. Observation.effective[x]:effectiveDateTime
SliceNameeffectiveDateTime
Definition

When the measurement was made

Control0..1
TypedateTime
[x] NoteSee Choice of Data Types for further information about how to use [x]
Must Supporttrue
Requirements

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

Comments

Conformance Rule: Observations of height and weight must be sent when there is an effective date.

Max Length0
48. Observation.issued
Definition

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

Control0..1
Typeinstant
Comments

Updated when the result is updated.

Max Length0
49. Observation.performer
Definition

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

Control0..*
TypeReference(Practitioner | Organization | Patient | RelatedPerson)
Requirements

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

Max Length0
50. Observation.value[x]
Definition

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

Control1..1
TypeQuantity
[x] NoteSee Choice of Data Types for further information about how to use [x]
Requirements

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

Comments

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 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, 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 boolean values use valueCodeableConcept and select codes from HL7 Version 2 Table 0136. These "yes/no" concepts can be mapped to the display name "true/false" or other mutually exclusive terms that may be needed. For further discussion and examples see the notes section below.

Max Length0
SlicingThis element introduces a set of slices on Observation.value[x]. The slices are unordered and Closed, and can be differentiated using the following discriminators:
  • type @ $this
51. Observation.value[x]:valueQuantity
SliceNamevalueQuantity
Definition

A measured amount (or an amount that can potentially be measured). Note that measured amounts include amounts that are not precisely quantified, including amounts involving arbitrary units and floating currencies.

Control1..1
TypeQuantity(Shared Health Quantity)
[x] NoteSee Choice of Data Types for further information about how to use [x]
Must Supporttrue
Requirements

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

Comments

Conformance Rule: This MUST be expressed in kilograms (weight), and centimeters (height). Value, System and Code will be set. For Body height; value - set to height measurement in centimeters system = http://unitsofmeasure.org code = cm For Body weight: value - set to weight measurement in kilograms system = http://unitsofmeasure.org code = kg

Max Length0
InvariantsDefined on this element
qty-3: If a code for the unit is present, the system SHALL also be present (: code.empty() or system.exists())
52. Observation.dataAbsentReason
Definition

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

Control0..1 This element is affected by the following invariants: obs-6
BindingThe codes SHALL be taken from Observation Value Absent Reason; other codes may be used where these codes are not suitable Codes specifying why the result (Observation.value[x]) is missing.

TypeCodeableConcept
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. Because of these options, use-case agreements are required to interpret general observations for exceptional values.

Max Length0
53. 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..1
BindingThe codes SHALL be taken from Observation Interpretation Codes; other codes may be used where these codes are not suitable Codes identifying interpretations of observations.

TypeCodeableConcept
Requirements

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

Alternate NamesAbnormal Flag
Max Length0
54. 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
Requirements

Need to be able to provide free text additional information.

Max Length0
55. Observation.bodySite
Definition

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

Control0..1
BindingFor example codes, see SNOMED CT Body Structures Codes describing anatomical locations. May include laterality.

TypeCodeableConcept
Requirements

Knowing where the observation is made is important for tracking if multiple sites are possible.

Comments

Only used if not implicit in code found in Observation.code. If the use case requires BodySite to be handled as a separate resource instead of an inline coded element (e.g. to identify and track separately) then use the standard extension body-site-instance.

Max Length0
56. Observation.method
Definition

Indicates the mechanism used to perform the observation.

Control0..1
BindingFor example codes, see Observation Methods Methods for simple observations.

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.

Max Length0
57. Observation.specimen
Definition

The specimen that was used when this observation was made.

Control0..1
TypeReference(Specimen)
Comments

Observations are not made on specimens themselves; they are made on a subject, but usually 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).

Max Length0
58. Observation.device
Definition

The device used to generate the observation data.

Control0..1
TypeReference(Device | DeviceMetric)
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 extension or through the Observation.related element.

Max Length0
59. Observation.referenceRange
Definition

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

Control0..*
TypeBackboneElement
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.

Max Length0
InvariantsDefined on this element
obs-3: Must have at least a low or a high or text (: low.exists() or high.exists() or text.exists())
60. Observation.referenceRange.id
Definition

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

Control0..1
Typeid
Max Length0
61. Observation.referenceRange.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.

Max Length0
62. Observation.referenceRange.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
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.

Max Length0
63. Observation.referenceRange.low
Definition

The value of the low bound of the reference range. The low bound of the reference range endpoint is inclusive of the value (e.g. reference range is >=5 - <=9). If the low bound is omitted, it is assumed to be meaningless (e.g. reference range is <=2.3).

Control0..1 This element is affected by the following invariants: obs-3
TypeQuantity(SimpleQuantity)
Max Length0
64. Observation.referenceRange.high
Definition

The value of the high bound of the reference range. The high bound of the reference range endpoint is inclusive of the value (e.g. reference range is >=5 - <=9). If the high bound is omitted, it is assumed to be meaningless (e.g. reference range is >= 2.3).

Control0..1 This element is affected by the following invariants: obs-3
TypeQuantity(SimpleQuantity)
Max Length0
65. Observation.referenceRange.meaning
Definition

Code for the meaning of the reference range.

Control0..1
BindingFor example codes, see Observation Reference Range Meaning Codes Code for the meaning of a reference range.

TypeCodeableConcept
Requirements

Need to be able to say what kind of reference range this is - normal, recommended, therapeutic, or perhaps what state this reference range applies to (i.e. age, hormonal cycles, etc.).

Comments

This SHOULD be populated if there is more than one range.

Max Length0
66. Observation.referenceRange.age
Definition

The age at which this reference range is applicable. This is a neonatal age (e.g. number of weeks at term) if the meaning says so.

Control0..1
TypeRange
Requirements

Some analytes vary greatly over age.

Max Length0
67. Observation.referenceRange.text
Definition

Text based reference range in an observation which may be used when a quantitative range is not appropriate for an observation. An example would be a reference value of "Negative" or a list or table of 'normals'.

Control0..1
Typestring
Max Length0
68. Observation.related
Definition

A reference to another resource (usually another Observation but could also be a QuestionnaireAnswer) whose relationship is defined by the relationship type code.

Control0..*
TypeBackboneElement
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 QuestionnaireResponse from which the measure is derived.

Comments

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

Max Length0
69. Observation.related.id
Definition

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

Control0..1
Typeid
Max Length0
70. 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.

Max Length0
71. 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
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.

Max Length0
72. Observation.related.type
Definition

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

Control0..1
BindingThe codes SHALL be taken from ObservationRelationshipType Codes specifying how two observations are related.

Typecode
Requirements

A relationship type SHOULD be provided.

Comments

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

Max Length0
73. Observation.related.target
Definition

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

Control1..1
TypeReference(Observation | QuestionnaireResponse)
Max Length0
74. 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..*
TypeBackboneElement
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 assembled in groups together see Notes below.

Max Length0
75. Observation.component.id
Definition

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

Control0..1
Typeid
Max Length0
76. Observation.component.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.

Max Length0
77. Observation.component.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
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.

Max Length0
78. Observation.component.code
Definition

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

Control1..1 This element is affected by the following invariants: obs-7
BindingFor example codes, see LOINC Codes Codes identifying names of simple observations.

TypeCodeableConcept
Requirements

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

Max Length0
79. Observation.component.value[x]
Definition

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

Control0..1
TypeChoice of: Quantity, CodeableConcept, string, Range, Ratio, SampledData, Attachment, time, dateTime, Period
[x] NoteSee Choice of Data Types for further information about how to use [x]
Requirements

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

Comments

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 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. 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 boolean values use valueCodeableConcept and select codes from <http://hl7.org/fhir/ValueSet/v2-0136> (These "yes/no" concepts can be mapped to the display name "true/false" or other mutually exclusive terms that may be needed"). The element, Observation.value[x], has a variable name depending on the type as follows: valueQuantity, valueCodeableConcept, valueRatio, valueChoice, valuePeriod, valueSampleData, or valueString (The name format is "'value' + the type name" with a capital on the first letter of the type).

Max Length0
80. Observation.component.dataAbsentReason
Definition

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

Control0..1 This element is affected by the following invariants: obs-6
BindingThe codes SHALL be taken from Observation Value Absent Reason; other codes may be used where these codes are not suitable Codes specifying why the result (Observation.value[x]) is missing.

TypeCodeableConcept
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 "test not done". 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. Because of these options, use-case agreements are required to interpret general observations for exceptional values.

Max Length0
81. Observation.component.referenceRange
Definition

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

Control0..*
TypeSee ttp://hl7.org/fhir/StructureDefinition/Observation#Observation.referenceRange
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.