Should be set to the identifier as set in the QuestionnaireResponse in the CarePlan.activity this response fulfills.

Sets expectations for supported capabilities for questionnaire responses for SDC-conformant systems.

The QuestionnaireResponse contains enough information about the questions asked and their organization that it can be interpreted somewhat independently from the Questionnaire it is based on. I.e. You don't need access to the Questionnaire in order to extract basic information from a QuestionnaireResponse.

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 it's narrative along with other profiles, value sets, etc.

Demographics and other administrative information about an individual or animal receiving care or other health-related services.

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

Represents a wet or electronic signature for either the form overall or for the question or item it's associated with.

Indicates how the individual completing the QuestionnaireResponse provided their responses.

Extension containing encrypted answers in a pgp encrypted format

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

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

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.

Should be set to the identifier as set in the QuestionnaireResponse in the CarePlan.activity this response fulfills.

Used for tracking, registration and other business purposes.

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.

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 Rendered Value extension. 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 order, proposal or plan that is fulfilled in whole or in part by this QuestionnaireResponse. For example, a ServiceRequest seeking an intake assessment or a decision support recommendation to assess for post-partum depression.

Supports traceability of responsibility for the action and allows linkage of an action to the recommendations acted upon.

The Questionnaire that defines and organizes the questions for which answers are being provided.

For SDC, this SHALL be the version-specific URL of the form as hosted on the Form Manager.

Needed to allow editing of the questionnaire response in a manner that enforces the constraints of the original form.

The title or other name to display when referencing a resource by canonical URL.

The position of the questionnaire response within its overall lifecycle.

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

Lifecycle status of the questionnaire response.

The information on Questionnaire resources may possibly be gathered during multiple sessions and altered after considered being finished.

The subject of the questionnaire response. This could be a patient, organization, practitioner, device, etc. This is who/what the answers apply to, but is not necessarily the source of information.

If the Questionnaire declared a subjectType, the resource pointed to by this element must be an instance of one of the listed types. If subject is omitted - because the QuestionnaireResponse is not associated with a specific subject, ensure that QuestionnaireRsponse.identifier is present or the QuestionnaireResponse is referenced somewhere (e.g. Task.output, Composition.section.entry, etc.) to allow tracking and retrieval of the QuestionnaireResponse

Allows linking the answers to the individual the answers describe. May also affect access control.

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.

Identifies when this version of the answer set was created. Changes whenever the answers are updated.

May be different from the lastUpdateTime of the resource itself, because that reflects when the data was known to the server, not when the data was captured.

This element is optional to allow for systems that might not know the value, however it SHOULD be populated if possible.

Clinicians need to be able to check the date that the information in the questionnaire was collected, to derive the context of the answers.

Person who received the answers to the questions in the QuestionnaireResponse and recorded them in the system.

Mapping a subject's answers to multiple choice options and determining what to put in the textual answer is a matter of interpretation. Authoring by device would indicate that some portion of the questionnaire had been auto-populated.

Need to know who interpreted the subject's answers to the questions in the questionnaire, and selected the appropriate options for answers.

The person who answered the questions about the subject.

If not specified, no inference can be made about who provided the data.

When answering questions about a subject that is minor, incapable of answering or an animal, another human source may answer the questions.

A group or question item from the original questionnaire for which answers are provided.

Groups cannot have answers and therefore must nest directly within item. When dealing with questions, nesting must occur within each answer because some questions may have multiple answers (and the nesting occurs for each answer).

Media to render/make available as an accompaniment to the question being asked

Represents a wet or electronic signature for either the form overall or for the question or item it's associated with.

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 manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. 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.

The item from the Questionnaire that corresponds to this item in the QuestionnaireResponse resource.

Items can repeat in the answers, so a direct 1..1 correspondence by position might not exist - requiring correspondence by identifier.

Text that is displayed above the contents of the group or as the text of the question being answered.

Allows the questionnaire response to be read without access to the questionnaire.

The respondent's answer(s) to the question.

The value is nested because we cannot have a repeating structure that has variable type.

Media to render/make available as an accompaniment to a specific answer option

A numeric value that allows the comparison (less than, greater than) or other numerical manipulation of a concept (e.g. Adding up components of a score). Scores are usually a whole number, but occasionally decimals are encountered in scores.

Scores are commonly encountered in various clinical assessment scales. Assigning a value to a concept should generally be done in a formal code system that defines the value, or in an applicable value set for the concept, but some concepts do not have a formal definition (or are not even represented as a concept formally, especially in Questionnaires, so this extension is allowed to appear ouside those preferred contexts. Scores may even be assigned arbitrarily during use (hence, on Coding). The value may be constrained to an integer in some contexts of use. Todo: Scoring algorithms may also be defined directly, but how this is done is not yet defined.

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 manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. 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.

The answer (or one of the answers) provided by the respondent to the question.

More complex structures (Attachment, Resource and Quantity) will typically be limited to electronic forms that can expose an appropriate user interface to capture the components and enforce the constraints of a complex data type. Additional complex types can be introduced through extensions. Must match the datatype specified by Questionnaire.item.type in the corresponding Questionnaire.

Code indicating the response provided for a question.

Ability to retain a single-valued answer to a question.

The answer (or one of the answers) provided by the respondent to the question.

More complex structures (Attachment, Resource and Quantity) will typically be limited to electronic forms that can expose an appropriate user interface to capture the components and enforce the constraints of a complex data type. Additional complex types can be introduced through extensions. Must match the datatype specified by Questionnaire.item.type in the corresponding Questionnaire.

Code indicating the response provided for a question.

Ability to retain a single-valued answer to a question.

An Extension

Extension containing encrypted string value

Extension containing encrypted open choice value

The answer (or one of the answers) provided by the respondent to the question.

More complex structures (Attachment, Resource and Quantity) will typically be limited to electronic forms that can expose an appropriate user interface to capture the components and enforce the constraints of a complex data type. Additional complex types can be introduced through extensions. Must match the datatype specified by Questionnaire.item.type in the corresponding Questionnaire.

Ability to retain a single-valued answer to a question.

An Extension

Extension containing encrypted integer value

The answer (or one of the answers) provided by the respondent to the question.

More complex structures (Attachment, Resource and Quantity) will typically be limited to electronic forms that can expose an appropriate user interface to capture the components and enforce the constraints of a complex data type. Additional complex types can be introduced through extensions. Must match the datatype specified by Questionnaire.item.type in the corresponding Questionnaire.

Ability to retain a single-valued answer to a question.

An Extension

Extension containing encrypted decimal value

The answer (or one of the answers) provided by the respondent to the question.

More complex structures (Attachment, Resource and Quantity) will typically be limited to electronic forms that can expose an appropriate user interface to capture the components and enforce the constraints of a complex data type. Additional complex types can be introduced through extensions. Must match the datatype specified by Questionnaire.item.type in the corresponding Questionnaire.

Code indicating the response provided for a question.

Ability to retain a single-valued answer to a question.

An Extension

Extension containing encrypted quantity value

How the value should be understood and represented - whether the actual value is greater or less than the stated value due to measurement issues; e.g. if the comparator is "<" , then the real value is < stated value.

How the Quantity should be understood and represented.

Need a framework for handling measures where the value is <5ug/L or >400mg/L due to the limitations of measuring methodology.

The answer (or one of the answers) provided by the respondent to the question.

More complex structures (Attachment, Resource and Quantity) will typically be limited to electronic forms that can expose an appropriate user interface to capture the components and enforce the constraints of a complex data type. Additional complex types can be introduced through extensions. Must match the datatype specified by Questionnaire.item.type in the corresponding Questionnaire.

Ability to retain a single-valued answer to a question.

An Extension

Extension containing encrypted date value

The answer (or one of the answers) provided by the respondent to the question.

More complex structures (Attachment, Resource and Quantity) will typically be limited to electronic forms that can expose an appropriate user interface to capture the components and enforce the constraints of a complex data type. Additional complex types can be introduced through extensions. Must match the datatype specified by Questionnaire.item.type in the corresponding Questionnaire.

Ability to retain a single-valued answer to a question.

An Extension

Extension containing encrypted dateTime value

The answer (or one of the answers) provided by the respondent to the question.

More complex structures (Attachment, Resource and Quantity) will typically be limited to electronic forms that can expose an appropriate user interface to capture the components and enforce the constraints of a complex data type. Additional complex types can be introduced through extensions. Must match the datatype specified by Questionnaire.item.type in the corresponding Questionnaire.

Ability to retain a single-valued answer to a question.

An Extension

Extension containing encrypted time value

The answer (or one of the answers) provided by the respondent to the question.

More complex structures (Attachment, Resource and Quantity) will typically be limited to electronic forms that can expose an appropriate user interface to capture the components and enforce the constraints of a complex data type. Additional complex types can be introduced through extensions. Must match the datatype specified by Questionnaire.item.type in the corresponding Questionnaire.

Ability to retain a single-valued answer to a question.

An Extension

Extension containing encrypted attachment value

The answer (or one of the answers) provided by the respondent to the question.

More complex structures (Attachment, Resource and Quantity) will typically be limited to electronic forms that can expose an appropriate user interface to capture the components and enforce the constraints of a complex data type. Additional complex types can be introduced through extensions. Must match the datatype specified by Questionnaire.item.type in the corresponding Questionnaire.

Ability to retain a single-valued answer to a question.

An Extension

Extension containing encrypted boolean value

The answer (or one of the answers) provided by the respondent to the question.

More complex structures (Attachment, Resource and Quantity) will typically be limited to electronic forms that can expose an appropriate user interface to capture the components and enforce the constraints of a complex data type. Additional complex types can be introduced through extensions. Must match the datatype specified by Questionnaire.item.type in the corresponding Questionnaire.

Code indicating the response provided for a question.

Ability to retain a single-valued answer to a question.

An Extension

Extension containing encrypted coding value

Nested groups and/or questions found within this particular answer.

It is useful to have "sub-questions", questions which normally appear when certain answers are given and which collect additional details.

Questions or sub-groups nested beneath a question or group.

Reports can consist of complex nested groups.

Sets expectations for supported capabilities for questionnaire responses for SDC-conformant systems.

The QuestionnaireResponse contains enough information about the questions asked and their organization that it can be interpreted somewhat independently from the Questionnaire it is based on. I.e. You don't need access to the Questionnaire in order to extract basic information from a QuestionnaireResponse.

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

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

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

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

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

The base language in which the resource is written.

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

A human language.

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

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

Demographics and other administrative information about an individual or animal receiving care or other health-related services.

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

Represents a wet or electronic signature for either the form overall or for the question or item it's associated with.

Indicates how the individual completing the QuestionnaireResponse provided their responses.

Extension containing encrypted answers in a pgp encrypted format

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

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

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.

Should be set to the identifier as set in the QuestionnaireResponse in the CarePlan.activity this response fulfills.

Used for tracking, registration and other business purposes.

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

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

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.

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.

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

This element deals only with general categories of identifiers. It SHOULD not be used for codes that correspond 1..1 with the Identifier.system. Some identifiers may fall into multiple categories due to common usage. Where the system is known, a type is unnecessary because the type is always part of the system definition. However systems often need to handle identifiers where the system is not known. There is not a 1:1 relationship between type and system, since many different systems have the same type.

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

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

Establishes the namespace for the value - that is, a 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 Rendered Value extension. 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.

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

Organization that issued/manages the identifier.

The Identifier.assigner may omit the .reference element and only contain a .display element reflecting the name or other textual information about the assigning organization.

The order, proposal or plan that is fulfilled in whole or in part by this QuestionnaireResponse. For example, a ServiceRequest seeking an intake assessment or a decision support recommendation to assess for post-partum depression.

Supports traceability of responsibility for the action and allows linkage of an action to the recommendations acted upon.

A procedure or observation that this questionnaire was performed as part of the execution of. For example, the surgery a checklist was executed as part of.

Composition of questionnaire responses will be handled by the parent questionnaire having answers that reference the child questionnaire. For relationships to referrals, and other types of requests, use basedOn.

The Questionnaire that defines and organizes the questions for which answers are being provided.

For SDC, this SHALL be the version-specific URL of the form as hosted on the Form Manager.

Needed to allow editing of the questionnaire response in a manner that enforces the constraints of the original form.

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

An Extension

The title or other name to display when referencing a resource by canonical URL.

Primitive value for canonical

The position of the questionnaire response within its overall lifecycle.

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

Lifecycle status of the questionnaire response.

The information on Questionnaire resources may possibly be gathered during multiple sessions and altered after considered being finished.

The subject of the questionnaire response. This could be a patient, organization, practitioner, device, etc. This is who/what the answers apply to, but is not necessarily the source of information.

If the Questionnaire declared a subjectType, the resource pointed to by this element must be an instance of one of the listed types. If subject is omitted - because the QuestionnaireResponse is not associated with a specific subject, ensure that QuestionnaireRsponse.identifier is present or the QuestionnaireResponse is referenced somewhere (e.g. Task.output, Composition.section.entry, etc.) to allow tracking and retrieval of the QuestionnaireResponse

Allows linking the answers to the individual the answers describe. May also affect access control.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

This is generally not the same as the Resource.text of the referenced resource. The purpose is to identify what's being referenced, not to fully describe it.

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

This will typically be the encounter the event occurred within, but some activities may be initiated prior to or after the official completion of an encounter but still be tied to the context of the encounter. A questionnaire that was initiated during an encounter but not fully completed during the encounter would still generally be associated with the encounter.

Provides context for the information that was captured. May also affect access control.

Identifies when this version of the answer set was created. Changes whenever the answers are updated.

May be different from the lastUpdateTime of the resource itself, because that reflects when the data was known to the server, not when the data was captured.

This element is optional to allow for systems that might not know the value, however it SHOULD be populated if possible.

Clinicians need to be able to check the date that the information in the questionnaire was collected, to derive the context of the answers.

Person who received the answers to the questions in the QuestionnaireResponse and recorded them in the system.

Mapping a subject's answers to multiple choice options and determining what to put in the textual answer is a matter of interpretation. Authoring by device would indicate that some portion of the questionnaire had been auto-populated.

Need to know who interpreted the subject's answers to the questions in the questionnaire, and selected the appropriate options for answers.

The person who answered the questions about the subject.

If not specified, no inference can be made about who provided the data.

When answering questions about a subject that is minor, incapable of answering or an animal, another human source may answer the questions.

A group or question item from the original questionnaire for which answers are provided.

Groups cannot have answers and therefore must nest directly within item. When dealing with questions, nesting must occur within each answer because some questions may have multiple answers (and the nesting occurs for each answer).

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

An Extension

Media to render/make available as an accompaniment to the question being asked

Represents a wet or electronic signature for either the form overall or for the question or item it's associated with.