This profile represents a Healthcare Associated Infection Singe-Person Report form as a FHIR Questionnaire.

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

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 version specific identifier, as it appears in the version portion of the URL. This values 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.

A reference to this profile (to which the instance claims to conform).

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.

A reference to a set of rules that were followed when the resource was constructed, and which must be understood when processing the content.

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.

This element is labelled as a modifier because the implicit rules may provide additional knowledge about the resource that modifies it's meaning or interpretation.

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

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 in formation 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.

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

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.

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

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.

An absolute URI that is used to identify this questionnaire when it is referenced in a specification, model, design or an instance. This SHALL be a URL, SHOULD be globally unique, and SHOULD be an address at which this questionnaire is (or will be) published. The URL SHOULD include the major version of the questionnaire. For more information see Technical and Business Versions.

… This is the id that will be used to link a QuestionnaireResponse to the Questionnaire the response is for.

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.

Globally unique identifier for the instance.

Allows externally provided and/or usable business identifiers to be easily associated with the module.

Typically, this is used for identifiers that can go in an HL7 V3 II (instance identifier) data type, e.g., to identify this questionnaire outside of FHIR, where it is not possible to use the logical URI.

The identifier that is used to identify this version of the questionnaire when it is referenced in a specification, model, design or instance. This is an arbitrary value managed by the questionnaire author and is not expected to be globally unique. For example, it might be a timestamp (e.g. yyyymmdd) if a managed version is not available. There is also no expectation that versions can be placed in a lexicographical sequence.

There may be different questionnaire instances that have the same identifier but different versions. The version can be appended to the url in a reference to allow a refrence to a particular business version of the questionnaire with the format [url]|[version].

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

Support human navigation and code generation.

The name is not expected to be globally unique. The name should be a simple alpha-numeric type name to ensure that it is computable friendly.

A short, descriptive, user-friendly title for the questionnaire.

This name does not need to be machine-processing friendly and may contain punctuation, white-space, etc.

The status of this questionnaire. Enables tracking the life-cycle of the content.

Allows filtering of questionnaires that are appropriate for use vs. not.
This is labeled as "Is Modifier" because applications should not use a retired questionnaire without due consideration.

A boolean value to indicate that this questionnaire is authored for testing purposes (or education/evaluation/marketing), and is not intended to be used for genuine usage.

Enables experimental content to be developed following the same lifecycle that would be used for a production-level questionnaire.

Allows filtering of questionnaire that are appropriate for use vs. not. This is labeled as "Is Modifier" because applications should not use an experimental questionnaire in production.

The date (and optionally time) when the questionnaire was published. The date must change if and when the business version changes and it must change if the status code changes. In addition, it should change when the substantive content of the questionnaire changes.

Note that this is not the same as the resource last-modified-date, since the resource may be a secondary representation of the questionnaire. Additional specific dates may be added as extensions or be found by consulting Provenances associated with past versions of the resource.

The name of the individual or organization that published the questionnaire.

Helps establish the "authority/credibility" of the questionnaire. May also allow for contact.

Usually an organization, but may be an individual. The publisher (or steward) of the questionnaire is the organization or individual primarily responsible for the maintenance and upkeep of the questionnaire. This is not necessarily the same individual or organization that developed and initially authored the content. The publisher is the primary point of contact for questions or issues with the questionnaire. This item SHOULD be populated unless the information is available from context.

A free text natural language description of the questionnaire from a consumer's perspective.

This description can be used to capture details such as why the questionnaire was built, comments about misuse, instructions for clinical use and interpretation, literature references, examples from the paper world, etc. It is not a rendering of the questionnaire as conveyed in the 'text' field of the resource itself. This item SHOULD be populated unless the information is available from context (e.g. the language of the profile is presumed to be the predominant language in the place the profile was created).

Explaination of why this questionnaire is needed and why it has been designed as it has.

This element does not describe the usage of the questionnaire Instead it provides traceability of ''why'' the resource is either needed or ''why'' it is defined as it is. This may be used to point to source materials or specifications that drove the structure of this questionnaire.

The date on which the resource content was approved by the publisher. Approval happens once when the content is officially approved for usage.

The 'date' element may be more recent than the approval date because of minor changes / editorial corrections.

The date on which the resource content was last reviewed. Review happens periodically after approval, but doesn't change the original approval date.

Gives a sense of how "current" the content is. Resources that have not been reviewed in a long time may have a risk of being less appropriate/relevant.

If specified, this is usually after the approval date.

The period during which the questionnaire content was or is planned to be in active use.

Allows establishing a transition before a resource comes into effect and also allows for a sunsetting process when new versions of a the questionnaire are or are expected to be used instead.

The effective period for a questionnaire determines when the content is applicable for usage and is independent of publication and review dates. For example, a measure intended to be used for the year 2016 might be published in 2015.

The content was developed with a focus and intent of supporting the contexts that are listed. These terms may be used to assist with indexing and searching for appropriate questionnaire instances.

Assist in searching for appropriate content.

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

A legal or geographic region in which the questionnaire is intended to be used.

It may be possible for the questionnaire to be used in jurisdictions other than those for which it was originally designed or intended.

Contact details to assist a user in finding and communicating with the publisher.

May be a web site, an email address, a telephone number, etc.

A copyright statement relating to the questionnaire and/or its contents. Copyright statements are generally legal restrictions on the use and publishing of the questionnaire.

Consumers must be able to determine any legal restrictions on the use of the questionnaire and/or its content.

LOINC code 51897-7 to indicate that this is a Healthcare Associated Infection Report

Allows linking of the complete Questionnaire resources to formal terminologies. It's common for "panels" of questions to be identified by a code.

Patient Resource (US Core Patient) is the subject of the related QuestionnaireResponse

If none are specified, then the subject is unlimited.

A particular question, question grouping or display text that is part of the questionnaire.

The content of the questionnaire is constructed from an ordered, hierarchical collection of items.

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

An Extension

Where the type for a question is "Reference", indicates a profile that the resource instances pointed to in answers to this question must be valid against.

If multiple profiles are present, then the resource must be valid against at least one of them.

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

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.

An identifier that is unique within the Questionnaire allowing linkage to the equivalent item in a QuestionnaireResponse resource.

QuestionnaireResponse does not require omitted items to be included and may have some items that repeat, so linkage based on position alone is not sufficient.

This ''can'' be a meaningful identifier (e.g. a LOINC code) but is not intended to have any meaning. GUIDs or sequential numbers are appropriate here.

A reference to an ElementDefinition that provides the details for the item. If a definition is provided, then the following element values can be inferred from the definition:

• code (ElementDefinition.code)
• type (ElementDefinition.type)
• required (ElementDefinition.min)
• repeats (ElementDefinition.max)
• maxLength (ElementDefinition.maxLength)
• options (ElementDefinition.binding)

Any information provided in these elements on a Questionnaire Item overrides the information from the definition.

A common pattern is to define a set of data elements and then build multiple questionnaires for different circumstances to gather the data. This element provides traceability to the common definition and allows the content for the question to come from the underlying definition.

the URI refers to an ElementDefinition in either a StructureDefinition or a DataElement, and always starts with the canonical URL for the target resource. When referring to a StructureDefinition, a fragment identifier is used to specify the element definition by its id Element.id. E.g. http://hl7.org/fhir/StructureDefinition/Observation#Observation.value[x]. In the absence of a fragment identifier, the first/root element definition in the target is the matching element definition. Note that LOINC codes implicitly define DataElement resources.

A terminology code that corresponds to this group or question (e.g. a code from LOINC, which defines many questions and answers).

Allows linking of groups of questions to formal terminologies.

The value may come from the ElementDefinition referred to by .definition.

A short label for a particular group, question or set of display text within the questionnaire used for reference by the individual completing the questionnaire.

Separating the label from the question text allows improved rendering. Also, instructions will often refer to specific prefixes, so there's a need for the questionnaire design to have control over what labels are used.

These are generally unique within a questionnaire, though this is not guaranteed. Some questionnaires may have multiple questions with the same label with logic to control which gets exposed.

Typically these won't be used for "display" items, though such use is not prohibited.

Systems SHOULD NOT generate their own prefixes if prefixes are defined for any items within a Questionnaire.

The name of a section, the text of a question or text content for a display item.

The type of questionnaire item this is - whether text for display, a grouping of other items or a particular type of data to be captured (string, integer, coded choice, etc.).

Defines the format in which the user is to be prompted for the answer.

Additional constraints on the type of answer can be conveyed by extensions. The value may come from the ElementDefinition referred to by .definition.

A constraint indicating that this item should only be enabled (displayed/allow answers to be captured) when the specified condition is true.

Allows questionnaires to adapt based on answers to other questions. E.g. If physical gender is specified as a male, no need to capture pregnancy history. Also allows conditional display of instructions or groups of questions.

If multiple repetitions of this extension are present, the item should be enabled when the condition for any of the repetitions is true. I.e. treat "enableWhen"s as being joined by an "or" clause.

This element is a modifier because if enableWhen is present for an item, "required" is ignored unless one of the enableWhen conditions is met.

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

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.

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

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 linkId for the question whose answer (or lack of answer) governs whether this item is enabled.

If multiple question occurrences are present for the same question (same linkId), then this refers to the nearest question occurrence reachable by tracing first the "ancestor" axis and then the "preceding" axis and then the "following" axis.

An indication that this item should be enabled only if the specified question is answered (hasAnswer=true) or not answered (hasAnswer=false).

If answered=false and answer values are also provided, then they are treated as "or". I.e. "Enable if the question is unanswered or the answer is one of the specified values". If answered=true and answers are present, one of the specified answers must be met. (So there's little reason to specify answered=true if answers are present.).

An answer that the referenced question must match in order for the item to be enabled.

Multiple answers are treated as "or". E.g. Enable if question 1 = A, C or E.

Components not specified in the answer do not need to match. For example, if enableWhen specifies code + system for a Coding, it is ok if the answer has a "display" element. I.e. treat the answer as a 'pattern'.

The dataType of this element must be the same as the data type of the question being referenced.

An indication, if true, that the item must be present in a "completed" QuestionnaireResponse. If false, the item may be skipped when answering the questionnaire.

Questionnaire.item.required only has meaning for elements that are conditionally enabled with enableWhen if the condition evaluates to true. If an item that contains other items is marked as required, that does not automatically make the contained elements required (though required groups must contain at least one child element). The value may come from the ElementDefinition referred to by .definition.

An indication, if true, that the item may occur multiple times in the response, collecting multiple answers answers for questions or multiple sets of answers for groups.

Items may be used to create set of (related) questions that can be repeated to give multiple answers to such a set.

If a question is marked as repeats=true, then multiple answers can be provided for the question in the corresponding QuestionnaireResponse. When rendering the questionnaire, it is up to the rendering software whether to render the question text for each answer repetition or to simply list each of the answers beneath the question. (Which is most appropriate visually may depend on the type of answer as well as whether there are nested items.). The value may come from the ElementDefinition referred to by .definition.

An indication, when true, that the value cannot be changed by a human respondent to the Questionnaire.

Allows certain information to be phrased (and rendered) as a question and an answer, while keeping users from changing it. May also be useful for preventing changes to pre-populated portions of a questionnaire, for calculated values, etc.

The value of readOnly elements can be established by asserting extensions for defaultValues, linkages that support pre-population and/or extensions that support calculation based on other answers.

The maximum number of characters that are permitted in the answer to be considered a "valid" QuestionnaireResponse.

For base64binary, reflects the number of characters representing the encoded data, not the number of bytes of the binary data. The value may come from the ElementDefinition referred to by .definition.

A reference to a value set containing a list of codes representing permitted answers for a "choice" or "open-choice" question.

LOINC defines many useful value sets for questionnaire responses. See LOINC Answer Lists. The value may come from the ElementDefinition referred to by .definition.

One of the permitted answers for a "choice" or "open-choice" question.

This element can be used when the value set machinery of options is deemed too cumbersome or when there's a need to capture options that are not codes.

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

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.

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

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 potential answer that's allowed as the answer to this question.

The data type of the value must agree with the item.type.

The value that should be defaulted when initially rendering the questionnaire for user input.

In some workflows, having defaults saves time.

The user is allowed to change the value and override the default (unless marked as read-only). If the user doesn't change the value, then this initial value will be persisted when the QuestionnaireResponse is initially created. Note that default values can influence results.

The data type of initial[x] must agree with the item.type.

Text, questions and other groups to be nested beneath a question or group.

Reports can consist of complex nested groups.

There is no specified limit to the depth of nesting. However, Questionnaire authors are encouraged to consider the impact on the user and user interface of overly deep nesting.

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

An Extension

Where the type for a question is "Reference", indicates a profile that the resource instances pointed to in answers to this question must be valid against.

If multiple profiles are present, then the resource must be valid against at least one of them.

Provides a computable unit of measure associated with numeric questions to support subsequent computation on responses.

The human-readable unit is conveyed as a display element. This element is for computation purposes.

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

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.

An identifier that is unique within the Questionnaire allowing linkage to the equivalent item in a QuestionnaireResponse resource.

QuestionnaireResponse does not require omitted items to be included and may have some items that repeat, so linkage based on position alone is not sufficient.

This ''can'' be a meaningful identifier (e.g. a LOINC code) but is not intended to have any meaning. GUIDs or sequential numbers are appropriate here.

A reference to an ElementDefinition that provides the details for the item. If a definition is provided, then the following element values can be inferred from the definition:

• code (ElementDefinition.code)
• type (ElementDefinition.type)
• required (ElementDefinition.min)
• repeats (ElementDefinition.max)
• maxLength (ElementDefinition.maxLength)
• options (ElementDefinition.binding)

Any information provided in these elements on a Questionnaire Item overrides the information from the definition.

A common pattern is to define a set of data elements and then build multiple questionnaires for different circumstances to gather the data. This element provides traceability to the common definition and allows the content for the question to come from the underlying definition.

the URI refers to an ElementDefinition in either a StructureDefinition or a DataElement, and always starts with the canonical URL for the target resource. When referring to a StructureDefinition, a fragment identifier is used to specify the element definition by its id Element.id. E.g. http://hl7.org/fhir/StructureDefinition/Observation#Observation.value[x]. In the absence of a fragment identifier, the first/root element definition in the target is the matching element definition. Note that LOINC codes implicitly define DataElement resources.

A terminology code that corresponds to this group or question (e.g. a code from LOINC, which defines many questions and answers).

Allows linking of groups of questions to formal terminologies.

The value may come from the ElementDefinition referred to by .definition.

A short label for a particular group, question or set of display text within the questionnaire used for reference by the individual completing the questionnaire.

Separating the label from the question text allows improved rendering. Also, instructions will often refer to specific prefixes, so there's a need for the questionnaire design to have control over what labels are used.

These are generally unique within a questionnaire, though this is not guaranteed. Some questionnaires may have multiple questions with the same label with logic to control which gets exposed.

Typically these won't be used for "display" items, though such use is not prohibited.

Systems SHOULD NOT generate their own prefixes if prefixes are defined for any items within a Questionnaire.

The name of a section, the text of a question or text content for a display item.

The type of questionnaire item this is - whether text for display, a grouping of other items or a particular type of data to be captured (string, integer, coded choice, etc.).

Defines the format in which the user is to be prompted for the answer.

Additional constraints on the type of answer can be conveyed by extensions. The value may come from the ElementDefinition referred to by .definition.

A constraint indicating that this item should only be enabled (displayed/allow answers to be captured) when the specified condition is true.

Allows questionnaires to adapt based on answers to other questions. E.g. If physical gender is specified as a male, no need to capture pregnancy history. Also allows conditional display of instructions or groups of questions.

If multiple repetitions of this extension are present, the item should be enabled when the condition for any of the repetitions is true. I.e. treat "enableWhen"s as being joined by an "or" clause.

This element is a modifier because if enableWhen is present for an item, "required" is ignored unless one of the enableWhen conditions is met.

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

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.

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

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 linkId for the question whose answer (or lack of answer) governs whether this item is enabled.

If multiple question occurrences are present for the same question (same linkId), then this refers to the nearest question occurrence reachable by tracing first the "ancestor" axis and then the "preceding" axis and then the "following" axis.

An indication that this item should be enabled only if the specified question is answered (hasAnswer=true) or not answered (hasAnswer=false).

If answered=false and answer values are also provided, then they are treated as "or". I.e. "Enable if the question is unanswered or the answer is one of the specified values". If answered=true and answers are present, one of the specified answers must be met. (So there's little reason to specify answered=true if answers are present.).

An answer that the referenced question must match in order for the item to be enabled.

Multiple answers are treated as "or". E.g. Enable if question 1 = A, C or E.

Components not specified in the answer do not need to match. For example, if enableWhen specifies code + system for a Coding, it is ok if the answer has a "display" element. I.e. treat the answer as a 'pattern'.

The dataType of this element must be the same as the data type of the question being referenced.

An indication, if true, that the item must be present in a "completed" QuestionnaireResponse. If false, the item may be skipped when answering the questionnaire.

Questionnaire.item.required only has meaning for elements that are conditionally enabled with enableWhen if the condition evaluates to true. If an item that contains other items is marked as required, that does not automatically make the contained elements required (though required groups must contain at least one child element). The value may come from the ElementDefinition referred to by .definition.

An indication, if true, that the item may occur multiple times in the response, collecting multiple answers answers for questions or multiple sets of answers for groups.

Items may be used to create set of (related) questions that can be repeated to give multiple answers to such a set.

If a question is marked as repeats=true, then multiple answers can be provided for the question in the corresponding QuestionnaireResponse. When rendering the questionnaire, it is up to the rendering software whether to render the question text for each answer repetition or to simply list each of the answers beneath the question. (Which is most appropriate visually may depend on the type of answer as well as whether there are nested items.). The value may come from the ElementDefinition referred to by .definition.

An indication, when true, that the value cannot be changed by a human respondent to the Questionnaire.

Allows certain information to be phrased (and rendered) as a question and an answer, while keeping users from changing it. May also be useful for preventing changes to pre-populated portions of a questionnaire, for calculated values, etc.

The value of readOnly elements can be established by asserting extensions for defaultValues, linkages that support pre-population and/or extensions that support calculation based on other answers.

The maximum number of characters that are permitted in the answer to be considered a "valid" QuestionnaireResponse.

For base64binary, reflects the number of characters representing the encoded data, not the number of bytes of the binary data. The value may come from the ElementDefinition referred to by .definition.

A reference to a value set containing a list of codes representing permitted answers for a "choice" or "open-choice" question.

LOINC defines many useful value sets for questionnaire responses. See LOINC Answer Lists. The value may come from the ElementDefinition referred to by .definition.

One of the permitted answers for a "choice" or "open-choice" question.

This element can be used when the value set machinery of options is deemed too cumbersome or when there's a need to capture options that are not codes.

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

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.

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

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 potential answer that's allowed as the answer to this question.

The data type of the value must agree with the item.type.

The value that should be defaulted when initially rendering the questionnaire for user input.

In some workflows, having defaults saves time.

The user is allowed to change the value and override the default (unless marked as read-only). If the user doesn't change the value, then this initial value will be persisted when the QuestionnaireResponse is initially created. Note that default values can influence results.

The data type of initial[x] must agree with the item.type.

Text, questions and other groups to be nested beneath a question or group.

Reports can consist of complex nested groups.

There is no specified limit to the depth of nesting. However, Questionnaire authors are encouraged to consider the impact on the user and user interface of overly deep nesting.