This profile represents a response to the Healthcare Associated Infection Single-Person Report Questionnaire as a FHIR QuestionnaireResponse profile.

Globally unique identifier for this QuestionnaireResponse.

References the single-person report questionnaire instance being answered.

In a single-person report, the author may be software (US Core Device) or may be a person in the role of infection control professional (ICP) (US Core Practitioner).

A questionnaire item

Text description of the questionnaire item

The answer to the questionnaire question (item)

This profile represents a response to the Healthcare Associated Infection Single-Person Report Questionnaire as a FHIR QuestionnaireResponse profile.

A structured set of questions and their answers. The questions are ordered and grouped into coherent subsets, corresponding to the structure of the grouping of the questionnaire being responded to.

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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.

Tags applied to this resource. Tags are intended to be used to identify and relate resources to process and workflow, and applications are not required to consider the tags when interpreting the meaning of a resource.

The tags can be updated without changing the stated version of the resource. The list of tags is a set. Uniqueness is based the system/code, and version and display are ignored.

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

• pattern @ $this

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

Need to refer to a particular code in the system.

Tags that a provider may use in their workflow to indicate/categorize that the context of this Questionnaire Response relates to Social Determinants of Health.

Tags applied to this resource. Tags are intended to be used to identify and relate resources to process and workflow, and applications are not required to consider the tags when interpreting the meaning of a resource.

The tags can be updated without changing the stated version of the resource. The list of tags is a set. Uniqueness is based the system/code, and version and display are ignored.

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.

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.

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.

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.

Globally unique identifier for this QuestionnaireResponse.

A business identifier assigned to a particular completed (or partially completed) questionnaire.

Used for tracking, registration and other business purposes.

References the single-person report questionnaire instance being answered.

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.

If a QuestionnaireResponse references a Questionnaire, then the QuestionnaireResponse structure must be consistent with the Questionnaire (i.e. questions must be organized into the same groups, nested questions must still be nested, etc.).

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.

This SHALL be the title of the Questionnaire at the time the QuestionnaireResponse was originally authored.

This extension is used when the survey,form, or questionnaire which is being anwered is not a FHIR Questionnaire, otherwise the canonical url for the FHIR Questionnaire is used.

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.

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

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

The date and/or time that this set of answers were last changed.

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.

In a single-person report, the author may be software (US Core Device) or may be a person in the role of infection control professional (ICP) (US Core Practitioner).

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.

A questionnaire item

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 description of the questionnaire item

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 answer to the questionnaire question (item)

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.

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.

This profile represents a response to the Healthcare Associated Infection Single-Person Report Questionnaire as a FHIR QuestionnaireResponse profile.

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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.

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.

• value @ url

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

The server assigns this value, and ignores what the client specifies, except in the case that the server is imposing version integrity on updates/deletes.

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

This value is always populated except when the resource is first being created. The server / resource manager sets this value; what a client provides is irrelevant. This is equivalent to the HTTP Last-Modified and SHOULD have the same value on a read interaction.

A uri that identifies the source system of the resource. This provides a minimal amount of Provenance information that can be used to track or differentiate the source of information in the resource. The source may identify another FHIR server, document, message, database, etc.

In the provenance resource, this corresponds to Provenance.entity.what[x]. The exact use of the source (and the implied Provenance.entity.role) is left to implementer discretion. Only one nominated source is allowed; for additional provenance details, a full Provenance resource should be used.

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

It is up to the server and/or other infrastructure of policy to determine whether/how these claims are verified and/or updated over time. The list of profile URLs is a set.

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

The security labels can be updated without changing the stated version of the resource. The list of security labels is a set. Uniqueness is based the system/code, and version and display are ignored.

Tags applied to this resource. Tags are intended to be used to identify and relate resources to process and workflow, and applications are not required to consider the tags when interpreting the meaning of a resource.

The tags can be updated without changing the stated version of the resource. The list of tags is a set. Uniqueness is based the system/code, and version and display are ignored.

• pattern @ $this

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.

• value @ url

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

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

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

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

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

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

Need to refer to a particular code in the system.

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

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

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

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

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

Tags that a provider may use in their workflow to indicate/categorize that the context of this Questionnaire Response relates to Social Determinants of Health.

The tags can be updated without changing the stated version of the resource. The list of tags is a set. Uniqueness is based the system/code, and version and display are ignored.

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-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.

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

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

• value @ url

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.

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.

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.

Globally unique identifier for this QuestionnaireResponse.

Used for tracking, registration and other business purposes.

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.

References the single-person report questionnaire instance being answered.

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

• value @ url

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

This SHALL be the title of the Questionnaire at the time the QuestionnaireResponse was originally authored.

This extension is used when the survey,form, or questionnaire which is being anwered is not a FHIR Questionnaire, otherwise the canonical url for the FHIR Questionnaire is used.

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.

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.

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

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.

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

In a single-person report, the author may be software (US Core Device) or may be a person in the role of infection control professional (ICP) (US Core Practitioner).

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 questionnaire item

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

• value @ url

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.

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.

A reference to an ElementDefinition that provides the details for the item.

The ElementDefinition must be in a StructureDefinition, and must have a fragment identifier that identifies the specific data element by its id (Element.id). E.g. http://hl7.org/fhir/StructureDefinition/Observation#Observation.value[x].

A common pattern is to define a set of data elements, and then build multiple different questionnaires for different circumstances to gather the data. This element provides traceability to the common definition.

Text description of the questionnaire item

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

The answer to the questionnaire question (item)

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

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

An Extension

• value @ url

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.

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.

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

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.