A structured set of questions intended to guide the collection of answers from end-users. Questionnaires provide detailed control over order, presentation, phraseology and grouping to allow coherent, consistent data collection.

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

Within the context of the FHIR RESTful interactions, the resource has an id except for cases like the create and conditional update. Otherwise, the use of the resouce id depends on the given use case.

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 its 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).

IETF language tag for 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 a 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, nor can they have their own independent transaction scope. This is allowed to be a Parameters resource if and only if it is referenced by a resource that provides context/meaning.

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

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

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 and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. To make the use of extensions safe and managable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer 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.

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

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

The determination of when to create a new version of a resource (same url, new version) vs. defining a new artifact is up to the author. Considerations for making this decision are found in Technical and Business Versions.

In some cases, the resource can no longer be found at the stated url, but the url itself cannot change. Implementations can use the meta.source element to indicate where the current master source of the resource can be found.

The name of the referenced questionnaire can be conveyed using the http://hl7.org/fhir/StructureDefinition/display extension.

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

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

A formal identifier that is used to identify this questionnaire when it is represented in other formats, or referenced in a specification, model, design or an instance.

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

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

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 questionnaires that have the same url but different versions. The version can be appended to the url in a reference to allow a reference to a particular business version of the questionnaire with the format. The version SHOULD NOT contain a '#' - see Business Version.

Indicates the mechanism used to compare versions to determine which is more current.

If set as a string, this is a FHIRPath expression that has two additional context variables passed in - %version1 and %version2 and will return a negative number if version1 is newer, a positive number if version2 and a 0 if the version ordering can't be successfully be determined.

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.

The name is not expected to be globally unique. The name should be a simple alphanumeric type no-whitespace name to ensure that it is machine-processing friendly.

Supports code generation.

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 URL of a Questionnaire that this Questionnaire is based on.

This element covers a broad range of relationships, from 'somewhat inspired by' to 'fully compliant with'. There is a standard extensionthat allows clearer differentiation between the specifics of the derivation relationship where this is needed - e.g. to determine substitutability and validation expectations - http://hl7.org/fhir/StructureDefinition/questionnaire-derivationType.

Allows a Questionnaire to be created based on another Questionnaire.

The current state of this questionnaire.

A nominal state-transition diagram can be found in the] documentation

Unknown does not represent 'other' - one of the defined statuses must apply. Unknown is used when the authoring system is not sure what the current status is.

See guidance around (not) making local changes to elements here.

The lifecycle status of an artifact.

Enables tracking the lifecycle of the content and filtering of questionnaires that are appropriate for use versus not.

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

Allows filtering of questionnaires that are appropriate for use versus not.

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

The types of subjects that can be the subject of responses created for the questionnaire.

If none are specified, then the subject is unlimited.

One of the resource types defined as part of this version of FHIR.

Allows enforcing that a QuestionnaireResponse only has a .subject element of the appropriate type.

The date (and optionally time) when the questionnaire was last significantly changed. The date must change 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.

The date is often not tracked until the resource is published, but may be present on draft content. 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.

See guidance around (not) making local changes to elements here.

The name of the organization or individual responsible for the release and ongoing maintenance of the questionnaire.

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.

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

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.

See guidance around (not) making local changes to elements here.

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

This description can be used to capture details such as 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 questionnaire is presumed to be the predominant language in the place the questionnaire was created).

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

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

Assist in searching for appropriate content.

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.

DEPRECATION NOTE: For consistency, implementations are encouraged to migrate to using the new 'jurisdiction' code in the useContext element. (I.e. useContext.code indicating http://terminology.hl7.org/CodeSystem/usage-context-type#jurisdiction and useContext.valueCodeableConcept indicating the jurisdiction.)

Countries and regions within which this artifact is targeted for use.

Explanation 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.

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

A short string (<50 characters), suitable for inclusion in a page footer that identifies the copyright holder, effective period, and optionally whether rights are resctricted. (e.g. 'All rights reserved', 'Some rights reserved').

The (c) symbol should NOT be included in this string. It will be added by software when rendering the notation. Full details about licensing, restrictions, warrantees, etc. goes in the more general 'copyright' element.

Defines the content expected to be rendered in all representations of the artifact.

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 or editorial corrections.

See guidance around (not) making local changes to elements here.

The date on which the resource content was last reviewed. Review happens periodically after approval but does not change the original approval date.

If specified, this date follows the original approval date.

See guidance around (not) making local changes to elements here.

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.

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

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 questionnaire intended to be used for the year 2016 might be published in 2015.

See guidance around (not) making local changes to elements here.

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

An identifier for this collection of questions in a particular terminology such as LOINC.

Codes for questionnaires, groups and individual questions.

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

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

该扩展用于指定调查问卷中哪一个条目可以被提取数据为Observation资源。

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

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

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

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

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

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.

LinkIds can have whitespaces and slashes by design. Tooling should not rely on linkIds being valid XHTML element IDs, and should not directly embed them as such

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 element is a URI that refers to an ElementDefinition or to an ObservationDefinition that provides information about this item, including information that might otherwise be included in the instance of the Questionnaire resource. A detailed description of the construction of the URI is shown in Comments, below.

The uri refers to an ElementDefinition in a StructureDefinition or to an ObservationDefinition 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.

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.

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

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

Codes for questionnaires, groups and individual questions.

Allows linking of groups of questions to formal terminologies.

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.

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.

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.

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

When using this element to represent the name of a section, use group type item and also make sure to limit the text element to a short string suitable for display as a section heading. Group item instructions should be included as a display type item within the group.

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, Coding, etc.).

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

Distinguishes groups from questions and display text and indicates data type for questions.

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

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

If multiple repetitions of this extension are present, the interpretation is driven by enableBehavior (either all repetitions must evaluate to true for this item to be enabled, or only one must evaluate to true for the item to be enabled). If the enableWhen.question has multiple answers, the condition evaluates to true if any of the answers for the referenced item match the enableWhen condition. This element is a modifier because if enableWhen is present for an item, "required" is ignored unless one of the enableWhen conditions is met. When an item is disabled, all of its descendants are disabled, regardless of what their own enableWhen logic might evaluate to. If enableWhen logic depends on an item that is disabled, the logic should proceed as though the item is not valued - even if a default value or other value might be retained in memory in the event of the item being re-enabled. In some cases, the comparison between the indicated answer and the specified value may differ only by precision. For example, the enableWhen might be Q1 > 1970, but the answer to Q1 is 1970-10-15. There is not a clear answer as to whether 1970-10-15 should be considered 'greater' than 1970, given that it is an imprecise value. In these indeterminate situations, the form filler has the option of refusing to render the form. If the form is displayed, items where enableWhen is indeterminate SHOULD be treated as enabled with a warning indicating that the questionnaire logic was faulty and it is possible that the item should not be enabled. Questionnaires SHOULD be designed to take into account challenges around varying precision to minimize non-deterministic situations by setting constraints around expected precision, etc.

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.

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

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 in which it is contained and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. To make the use of extensions safe and managable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. Applications processing a resource are required to check for modifier extensions.

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

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

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

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. If there are multiple items with the same linkId and all are equadistant (e.g. a question references a question that appears in a separate repeating group), that is an error. (Consider using the enableWhenExpression extension to define logic to handle such a situation.)

Specifies the criteria by which the question is enabled.

The criteria by which a question is enabled.

A value that the referenced question is tested using the specified operator in order for the item to be enabled. If there are multiple answers, a match on any of the answers suffices. If different behavior is desired (all must match, at least 2 must match, etc.), consider using the enableWhenExpression extension.

Allowed values to answer questions.

Controls how multiple enableWhen values are interpreted - whether all or any must be true.

This element must be specified if more than one enableWhen value is provided.

Controls how multiple enableWhen values are interpreted - whether all or any must be true.

Indicates if and how items that are disabled (because enableWhen evaluates to 'false') should be displayed.

If not specified, rendering behavior is up to the client. This element is only meaningful if enableWhen or an equivalent extension is present

Defines how disabled elements should be rendered

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.

If the required item is a question, it must have a direct answer (i.e. an answer to the question itself, not merely answers to child questions) in order for the QuestionnaireResponse to be complete. If the required item is a group, it must have at least one descendant question which has an answer Questionnaire.item.required only has meaning for elements that are conditionally enabled with enableWhen if the condition evaluates to true. It also only has meaning if the parent element is present. If a non-required 'group' item contains a 'required' question item, it's completely fine to omit the group (because it's not required) despite it having a required child. Similarly, 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 descendant item with a populated answer). The value for 'required' may come from the ElementDefinition referred to by .definition.

An indication, if true, that a QuestionnaireResponse for this item may include multiple answers associated with a single instance of this item (for question-type items) or multiple repetitions of the item (for group-type items).

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 (i.e. "repeat the question") or to simply allow entry/selection of multiple answers for the question (repeat the answers). Which is most appropriate visually may depend on the type of answer as well as whether there are nested items.

The resulting QuestionnaireResponse will be populated the same way regardless of rendering - one 'question' item with multiple answer values.

The value may come from the ElementDefinition referred to by .definition. When repeats=true for a group, it'll be represented with multiple items with the same linkId in the QuestionnaireResponse. For a question, it'll be represented by a single item with that linkId with multiple answers.

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

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

If specified on a 'group', then all items beneath the specified group are read only. For questions, this only marks the answer associated with the specific item read only. Descendant questions are not impacted. 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.

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 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.

For items that have a defined set of allowed answers (via answerOption or answerValueSet), indicates whether values other than those specified can be selected.

Indicates differnt modes for restricting values when options or valueset are specified

Introduces the ability for questions to have 'other' answers

A reference to a value set containing a list of values representing permitted answers for a 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 the question.

This element can be used when the value set machinery of answerValueSet is deemed too cumbersome or when there's a need to capture possible answers 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. To make the use of extensions safe and managable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension.

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 in which it is contained and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. To make the use of extensions safe and managable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. Applications processing a resource are required to check for modifier extensions.

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

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

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

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

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

Allowed values to answer questions.

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

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

Allowed values to answer questions.

Indicates whether the answer value is selected when the list of possible answers is initially shown.

One or more values that should be pre-populated in the answer when initially rendering the questionnaire for user input.

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 initial values can influence results. The data type of initial.answer[x] must agree with the item.type, and only repeating items can have more then one initial value.

In some workflows, having defaults saves time.

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

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 in which it is contained and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. To make the use of extensions safe and managable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. Applications processing a resource are required to check for modifier extensions.

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

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

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

The actual value to for an initial answer.

The type of the initial value must be consistent with the type of the item.

Allowed values to answer questions.

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

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.

Reports can consist of complex nested groups.