A set of healthcare-related information that is assembled together into a single logical package that provides a single coherent statement of meaning, establishes its own context and that has clinical attestation with regard to who is making the statement. A Composition defines the structure and narrative content necessary for a document. However, a Composition alone does not constitute a document. Rather, the Composition must be the first entry in a Bundle where Bundle.type=document, and any other resources referenced from Composition must be included as subsequent entries in the Bundle (for example Patient, Practitioner, Encounter, etc.).

While the focus of this specification is on patient-specific clinical statements, this resource can also apply to other healthcare-related statements such as study protocol designs, healthcare invoices and other activities that are not necessarily patient-specific or clinical.

A reference to a set of rules that were followed when the resource was constructed, and which must be understood when processing the content. Often, this is a reference to an implementation guide that defines the special rules along with other profiles etc.

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

These resources do not have an independent existence apart from the resource that contains them - they cannot be identified independently, nor can they have their own independent transaction scope. This is allowed to be a Parameters resource if and only if it is referenced by a resource that provides context/meaning.

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

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

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.

A reference to a set of rules that were followed when the resource was constructed, and which must be understood when processing the content. Often, this is a reference to an implementation guide that defines the special rules along with other profiles etc.

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

These resources do not have an independent existence apart from the resource that contains them - they cannot be identified independently, nor can they have their own independent transaction scope. This is allowed to be a Parameters resource if and only if it is referenced by a resource that provides context/meaning.

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

An Extension

A unique identifier assigned to this observation.

Allows observations to be distinguished and referenced.

The reference to a FHIR ObservationDefinition resource that provides the definition that is adhered to in whole or in part by this Observation instance.

ObservationDefinition can be referenced by its canonical url using instantiatesCanonical, or by a name or an identifier using the appropriate sub-elements of instantiatesReference.

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.

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

Identifies the observation(s) that triggered the performance of this observation.

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

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

The status of the result value.

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

Codes providing the status of an observation.

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

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

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.

Codes for high level observation categories.

Used for filtering what observations are retrieved and displayed.

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

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.

Codes identifying names of simple observations.

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

The patient, or group of patients, location, device, organization, procedure or practitioner this observation is about and into whose or what 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.

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. The subject of an Observation may in some cases be a procedure. This supports the regulatory inspection use case where observations are captured during inspections of a procedure that is being performed (independent of any particular patient or whether patient related at all).

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

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.

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 http://hl7.org/fhir/StructureDefinition/observation-focusCode.

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

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).

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

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.

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.

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

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

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.

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

• An observation may have:
  1. a single value here
  2. both a value and a set of related or component values
  3. only a set of related or component values.
• If a value is present, the datatype for this element should be determined by the code.
• 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 code defines a coded value.
• Attachment is used if the observation result value is a binary file such as an image. If the observation result value is derived from the binary file (for example 'X' detected and here is the the proof in this image), the binary file may be directly represented using DocumentReference and referenced by derivedFrom.
• The usage of valueReference is restricted to the MolecularSequence resource when used as a definitional resource, not as a patient-specific finding. .
• For additional guidance, see the Notes section below.

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

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

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.

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

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

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

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.

Codes identifying interpretations of observations.

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

Comments about the observation or the results.

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.

Need to be able to provide free text additional information.

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

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.

SNOMED CT Body site concepts

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

Only used if not implicit in code found in Observation.code or bodySite is used. In many systems, this may be represented as a related observation instead of an inline component.

Indicates the mechanism used to perform the observation.

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

Methods for simple observations.

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

The specimen that was used when this observation was made.

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).

A reference to the device that generates the measurements or the device settings for the device.

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.

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.

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.

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.

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

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.

A reference to a set of rules that were followed when the resource was constructed, and which must be understood when processing the content. Often, this is a reference to an implementation guide that defines the special rules along with other profiles etc.

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

These resources do not have an independent existence apart from the resource that contains them - they cannot be identified independently, nor can they have their own independent transaction scope. This is allowed to be a Parameters resource if and only if it is referenced by a resource that provides context/meaning.

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

An Extension

A unique identifier assigned to this observation.

Allows observations to be distinguished and referenced.

The reference to a FHIR ObservationDefinition resource that provides the definition that is adhered to in whole or in part by this Observation instance.

ObservationDefinition can be referenced by its canonical url using instantiatesCanonical, or by a name or an identifier using the appropriate sub-elements of instantiatesReference.

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.

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

Identifies the observation(s) that triggered the performance of this observation.

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

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

The status of the result value.

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

Codes providing the status of an observation.

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

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

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.

Codes for high level observation categories.

Used for filtering what observations are retrieved and displayed.

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

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.

Codes identifying names of simple observations.

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

The patient, or group of patients, location, device, organization, procedure or practitioner this observation is about and into whose or what 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.

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. The subject of an Observation may in some cases be a procedure. This supports the regulatory inspection use case where observations are captured during inspections of a procedure that is being performed (independent of any particular patient or whether patient related at all).

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

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.

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 http://hl7.org/fhir/StructureDefinition/observation-focusCode.

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

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).

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

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.

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.

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

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

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.

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

• An observation may have:
  1. a single value here
  2. both a value and a set of related or component values
  3. only a set of related or component values.
• If a value is present, the datatype for this element should be determined by the code.
• 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 code defines a coded value.
• Attachment is used if the observation result value is a binary file such as an image. If the observation result value is derived from the binary file (for example 'X' detected and here is the the proof in this image), the binary file may be directly represented using DocumentReference and referenced by derivedFrom.
• The usage of valueReference is restricted to the MolecularSequence resource when used as a definitional resource, not as a patient-specific finding. .
• For additional guidance, see the Notes section below.

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

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

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.

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

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

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

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.

Codes identifying interpretations of observations.

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

Comments about the observation or the results.

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.

Need to be able to provide free text additional information.

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

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.

SNOMED CT Body site concepts

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

Only used if not implicit in code found in Observation.code or bodySite is used. In many systems, this may be represented as a related observation instead of an inline component.

Indicates the mechanism used to perform the observation.

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

Methods for simple observations.

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

The specimen that was used when this observation was made.

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).

A reference to the device that generates the measurements or the device settings for the device.

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.

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.

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.

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.

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.

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

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.

An Extension

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

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

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

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

Used when observation has a set of component observations:

• An observation may have both a value (e.g. an Apgar score) and component observations (the observations from which the Apgar score was derived).
• If a value is present, the datatype for this element should be determined by the code.
• 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 code defines a coded value.
• Attachment is used if the observation result value is a binary file such as an image. If the observation result value is derived from the binary file (for example 'X' detected and here is the the proof in this image), the binary file may be directly represented using DocumentReference and referenced by derivedFrom.
• If a value is present, the datatype for this element should be determined by the code.
• 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 code defines a coded value.
• Attachment is used if the observation result value is a binary file such as an image. If the observation result value is derived from the binary file (for example 'X' detected and here is the the proof in this image), the binary file may be directly represented using DocumentReference and referenced by derivedFrom.
• The usage of valueReference is restricted to the MolecularSequence resource when used as a definitional resource, not as a patient-specific finding. .
• For additional guidance, see the Notes section below.

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

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

Used when observation has a set of component observations:

• An observation may have both a value (e.g. an Apgar score) and component observations (the observations from which the Apgar score was derived).
• If a value is present, the datatype for this element should be determined by the code.
• 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 code defines a coded value.
• Attachment is used if the observation result value is a binary file such as an image. If the observation result value is derived from the binary file (for example 'X' detected and here is the the proof in this image), the binary file may be directly represented using DocumentReference and referenced by derivedFrom.
• If a value is present, the datatype for this element should be determined by the code.
• 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 code defines a coded value.
• Attachment is used if the observation result value is a binary file such as an image. If the observation result value is derived from the binary file (for example 'X' detected and here is the the proof in this image), the binary file may be directly represented using DocumentReference and referenced by derivedFrom.
• The usage of valueReference is restricted to the MolecularSequence resource when used as a definitional resource, not as a patient-specific finding. .
• For additional guidance, see the Notes section below.

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

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

Used when observation has a set of component observations:

• An observation may have both a value (e.g. an Apgar score) and component observations (the observations from which the Apgar score was derived).
• If a value is present, the datatype for this element should be determined by the code.
• 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 code defines a coded value.
• Attachment is used if the observation result value is a binary file such as an image. If the observation result value is derived from the binary file (for example 'X' detected and here is the the proof in this image), the binary file may be directly represented using DocumentReference and referenced by derivedFrom.
• If a value is present, the datatype for this element should be determined by the code.
• 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 code defines a coded value.
• Attachment is used if the observation result value is a binary file such as an image. If the observation result value is derived from the binary file (for example 'X' detected and here is the the proof in this image), the binary file may be directly represented using DocumentReference and referenced by derivedFrom.
• The usage of valueReference is restricted to the MolecularSequence resource when used as a definitional resource, not as a patient-specific finding. .
• For additional guidance, see the Notes section below.

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

These resources do not have an independent existence apart from the resource that contains them - they cannot be identified independently, nor can they have their own independent transaction scope. This is allowed to be a Parameters resource if and only if it is referenced by a resource that provides context/meaning.

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

A reference to a set of rules that were followed when the resource was constructed, and which must be understood when processing the content. Often, this is a reference to an implementation guide that defines the special rules along with other profiles etc.

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

These resources do not have an independent existence apart from the resource that contains them - they cannot be identified independently, nor can they have their own independent transaction scope. This is allowed to be a Parameters resource if and only if it is referenced by a resource that provides context/meaning.

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

An Extension

Practitioner that is able to provide the defined services for the organization.

The organization where the Practitioner performs the roles associated.

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

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.

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

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.

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

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.

An Extension

An absolute URI that is used to identify this Composition when it is referenced in a specification, model, design or an instance; also called its canonical identifier. This SHOULD be globally unique and SHOULD be a literal address at which an authoritative instance of this Composition is (or will be) published. This URL can be the target of a canonical reference. It SHALL remain the same when the Composition is stored on different servers.

Can be a urn:uuid: or a urn:oid: but real http: addresses are preferred. Multiple instances may share the same URL if they have a distinct version.

Allows the Composition to be referenced by a single globally unique identifier.

A version-independent identifier for the Composition. This identifier stays constant as the composition is changed over time.

Similar to ClinicalDocument/setId in CDA. See discussion in resource definition for how these relate.

The purpose of this identifier.

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

Identifies the purpose for this identifier, if known .

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

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

Identifier.system is always case sensitive.

There are many sets of identifiers. To perform matching of two identifiers, we need to know what set we're dealing with. The system identifies a particular set of unique identifiers.

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

If the value is a full URI, then the system SHALL be urn:ietf:rfc:3986. The value's primary purpose is computational mapping. As a result, it may be normalized for comparison purposes (e.g. removing non-significant whitespace, dashes, etc.) A value formatted for human display can be conveyed using the http://hl7.org/fhir/StructureDefinition/rendered-value). Identifier.value is to be treated as case sensitive unless knowledge of the Identifier.system allows the processer to be confident that non-case-sensitive processing is safe.

The workflow/clinical status of this composition. The status is a marker for the clinical standing of the document.

If a composition is marked as withdrawn, the compositions/documents in the series, or data from the composition or document series, should never be displayed to a user without being clearly marked as untrustworthy. The flag "entered-in-error" is why this element is labeled as a modifier of other elements.

Some reporting work flows require that the original narrative of a final document never be altered; instead, only new narrative can be added. The composition resource has no explicit status for explicitly noting whether this business rule is in effect. This would be handled by an extension if required.

Need to be able to mark interim, amended, or withdrawn compositions or documents.

Specifies the particular kind of composition (e.g. History and Physical, Discharge Summary, Progress Note). This usually equates to the purpose of making the composition.

For Composition type, LOINC is ubiquitous and strongly endorsed by HL7. Most implementation guides will require a specific LOINC code, or use LOINC as an extensible binding.

Type of a composition.

Key metadata element describing the composition, used in searching/filtering.

A reference to a code defined by a terminology system.

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

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

A categorization for the type of the composition - helps for indexing and searching. This may be implied by or derived from the code specified in the Composition Type.

Helps humans to assess whether the composition is of interest when viewing an index of compositions or documents.

Who or what the composition is about. The composition can be about a person, (patient or healthcare practitioner), a device (e.g. a machine) or even a group of subjects (such as a document about a herd of livestock, or a set of patients that share a common exposure).

For clinical documents, this is usually the patient.

Essential metadata for searching for the composition. Identifies who and/or what the composition/document is about.

A reference to a location at which the other resource is found. The reference may be a relative reference, in which case it is relative to the service base URL, or an absolute URL that resolves to the location where the resource is found. The reference may be version specific or not. If the reference is not to a FHIR RESTful server, then it should be assumed to be version specific. Internal fragment references (start with '#') refer to contained resources.

Using absolute URLs provides a stable scalable approach suitable for a cloud/web context, while using relative/logical references provides a flexible approach suitable for use when trading across closed eco-system boundaries. Absolute URLs do not need to point to a FHIR RESTful server, though this is the preferred approach. If the URL conforms to the structure "[type]/[id]" then it should be assumed that the reference is to a FHIR RESTful server.

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

When an identifier is provided in place of a reference, any system processing the reference will only be able to resolve the identifier to a reference if it understands the business context in which the identifier is used. Sometimes this is global (e.g. a national identifier) but often it is not. For this reason, none of the useful mechanisms described for working with references (e.g. chaining, includes) are possible, nor should servers be expected to be able resolve the reference. Servers may accept an identifier based reference untouched, resolve it, and/or reject it - see CapabilityStatement.rest.resource.referencePolicy.

When both an identifier and a literal reference are provided, the literal reference is preferred. Applications processing the resource are allowed - but not required - to check that the identifier matches the literal reference

Applications converting a logical reference to a literal reference may choose to leave the logical reference present, or remove it.

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

This element only allows for a single identifier. In the case where additional identifers are required, use the http://hl7.org/fhir/StructureDefinition/additionalIdentifier extension.

The purpose of this identifier.

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

Identifies the purpose for this identifier, if known .

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

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

Identifier.system is always case sensitive.

There are many sets of identifiers. To perform matching of two identifiers, we need to know what set we're dealing with. The system identifies a particular set of unique identifiers.

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

If the value is a full URI, then the system SHALL be urn:ietf:rfc:3986. The value's primary purpose is computational mapping. As a result, it may be normalized for comparison purposes (e.g. removing non-significant whitespace, dashes, etc.) A value formatted for human display can be conveyed using the http://hl7.org/fhir/StructureDefinition/rendered-value). Identifier.value is to be treated as case sensitive unless knowledge of the Identifier.system allows the processer to be confident that non-case-sensitive processing is safe.

Describes the clinical encounter or type of care this documentation is associated with.

Provides context for the composition and supports searching.

The composition editing time, when the composition was last logically changed by the author.

The Last Modified Date on the composition may be after the date of the document was attested without being changed. This means that the date on an amended document is the date of the amendment, not the date of original authorship.

dateTime is used for tracking, organizing versions and searching. Note that this is the time of authoring this version of the Composition. When packaged in a document, Bundle.timestamp is the date of packaging.

The content was developed with a focus and intent of supporting the contexts that are listed. These contexts may be general categories (gender, age, ...) or may be references to specific programs (insurance plans, studies, ...) and may be used to assist with indexing and searching for appropriate Composition instances.

When multiple useContexts are specified, there is no expectation that all or any of the contexts apply.

Assist in searching for appropriate content.

Identifies who is responsible for the information in the composition, not necessarily who typed it in.

Identifies who is responsible for the content.

A natural language name identifying the {{title}}. This name should be usable as an identifier for the module by machine processing applications such as code generation.

The name is not expected to be globally unique. The name should be a simple alphanumeric type name to ensure that it is machine-processing friendly.

Support human navigation and code generation.

Official human-readable label for the composition.

For many compositions, the title is the same as the text or a display name of Composition.type (e.g. a "consultation" or "progress note"). Note that CDA does not make title mandatory, but there are no known cases where it is useful for title to be omitted, so it is mandatory here. Feedback on this requirement is welcome during the trial use period.

For any additional notes.

A comment, general note or annotation not coded elsewhere.

A participant who has attested to the accuracy of the composition/document.

Only list each attester once.

Identifies responsibility for the accuracy of the composition content.

Identifies the organization or group who is responsible for ongoing maintenance of and access to the composition/document information.

This is useful when documents are derived from a composition - provides guidance for how to get the latest version of the document. This is optional because this is sometimes not known by the authoring system, and can be inferred by context. However, it is important that this information be known when working with a derived document, so providing a custodian is encouraged.

Identifies where to go to find the current version, where to report issues, etc.

Relationships that this composition has with other compositions or documents that already exist.

To reference (using relatesTo) a Bundle of type "document" or another Composition where you only have the identifier, use a resourceReference with an identifier.
When a Composition is an alternate representation of another type of document e.g. CDA, the other document could be referenced in a DocumentReference resource.
Here is an example of using relatesTo to reference another Bundle of type "document" or Composition where you only have the identifier:

"relatesTo": [{
  "type": "replaces",
  "resourceReference": {
    "identifier": { 
      "system": "...", 
      "value": "..."
    }
  } 
}]

The clinical service, such as a colonoscopy or an appendectomy, being documented.

The event needs to be consistent with the type element, though can provide further information if desired.

Provides context for the composition and creates a linkage between a resource describing an event and the composition created describing the event.

An Extension

Represents the main clinical acts, such as a colonoscopy or an appendectomy, being documented. In some cases, the event is inherent in the typeCode, such as a "History and Physical Report" in which case the procedure being documented is necessarily a "History and Physical" act. The events may be included as a code or as a reference to an other resource.

An event can further specialize the act inherent in the typeCode, such as where it is simply "Procedure Report" and the procedure was a "colonoscopy". If one or more events are included, they SHALL NOT conflict with the values inherent in the classCode, practiceSettingCode or typeCode, as such a conflict would create an ambiguous situation. This short list of codes is provided to be used as key words for certain types of queries.

This list of codes represents the main clinical acts being documented.

The root of the sections that make up the composition.

May be used to represent additional information that is not part of the basic definition of the element and that modifies the understanding of the element in which it is contained and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. To make the use of extensions safe and managable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. Applications processing a resource are required to check for modifier extensions.

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

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

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

A reference to the actual resource from which the narrative in the section is derived.

If there are no entries in the list, an emptyReason SHOULD be provided.

The root of the sections that make up the composition.

An Extension

A code identifying the kind of content contained within the section. This must be consistent with the section title.

The code identifies the section for an automated processor of the document. This is particularly relevant when using profiles to control the structure of the document.

If the section has content (instead of sub-sections), the section.code does not change the meaning or interpretation of the resource that is the content of the section in the comments for the section.code.

Classification of a section of a composition/document.

Provides computable standardized labels to topics within the document.

A reference to the actual resource from which the narrative in the section is derived.

If there are no entries in the list, an emptyReason SHOULD be provided.

The root of the sections that make up the composition.

An Extension

A code identifying the kind of content contained within the section. This must be consistent with the section title.

The code identifies the section for an automated processor of the document. This is particularly relevant when using profiles to control the structure of the document.

If the section has content (instead of sub-sections), the section.code does not change the meaning or interpretation of the resource that is the content of the section in the comments for the section.code.

Classification of a section of a composition/document.

Provides computable standardized labels to topics within the document.

A reference to the actual resource from which the narrative in the section is derived.

If there are no entries in the list, an emptyReason SHOULD be provided.

A reference to a location at which the other resource is found. The reference may be a relative reference, in which case it is relative to the service base URL, or an absolute URL that resolves to the location where the resource is found. The reference may be version specific or not. If the reference is not to a FHIR RESTful server, then it should be assumed to be version specific. Internal fragment references (start with '#') refer to contained resources.

Using absolute URLs provides a stable scalable approach suitable for a cloud/web context, while using relative/logical references provides a flexible approach suitable for use when trading across closed eco-system boundaries. Absolute URLs do not need to point to a FHIR RESTful server, though this is the preferred approach. If the URL conforms to the structure "[type]/[id]" then it should be assumed that the reference is to a FHIR RESTful server.

The root of the sections that make up the composition.

An Extension

A code identifying the kind of content contained within the section. This must be consistent with the section title.

The code identifies the section for an automated processor of the document. This is particularly relevant when using profiles to control the structure of the document.

If the section has content (instead of sub-sections), the section.code does not change the meaning or interpretation of the resource that is the content of the section in the comments for the section.code.

Classification of a section of a composition/document.

Provides computable standardized labels to topics within the document.

A reference to the actual resource from which the narrative in the section is derived.

If there are no entries in the list, an emptyReason SHOULD be provided.

The root of the sections that make up the composition.

An Extension

A code identifying the kind of content contained within the section. This must be consistent with the section title.

The code identifies the section for an automated processor of the document. This is particularly relevant when using profiles to control the structure of the document.

If the section has content (instead of sub-sections), the section.code does not change the meaning or interpretation of the resource that is the content of the section in the comments for the section.code.

Classification of a section of a composition/document.

Provides computable standardized labels to topics within the document.