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.

This element can be used to indicate where the current master source of a resource that has a canonical URL if the resource is no longer hosted at the canonical URL.

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.

Source of the definition for the extension code - a logical name or a URL.

The definition may point directly to a computable or human-readable definition of the extensibility codes, or it may be a logical URI as declared in some other specification. The definition SHALL be a URI for the Structure Definition defining the extension.

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 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.

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

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

The purpose of this identifier.

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

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

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

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

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

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

A Period specifies a range of time; the context of use will specify whether the entire range applies (e.g. "the patient was an inpatient of the hospital for this time range") or one value from the range applies (e.g. "give to the patient between these two times").

Period is not used for a duration (a measure of elapsed time). See Duration.

Organization that issued/manages the identifier.

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

The 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 reference 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 alphanumeric type name to ensure that it is machine-processing 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 URL of a Questionnaire that this Questionnaire is based on.

Allows a Questionnaire to be created based on another Questionnaire.

see Canonical References

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

Allows 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 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 questionnaires that are appropriate for use versus not.

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

If none are specified, then the subject is unlimited.

The name of the organization or individual 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.

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 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 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 questionnaire instances.

Assist in searching for appropriate content.

When multiple useContexts are specified, there is no expectation that 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.

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

Systems are not required to have markdown support, so the text should be readable without markdown processing. The markdown syntax is GFM - see https://github.github.com/gfm/

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.

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

An identifier for this question or group of questions in a particular terminology such as LOINC.

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

Codes may be defined very casually in enumerations or code lists, up to very formal definitions such as SNOMED CT - see the HL7 v3 Core Principles for more information.

This element is a URI that refers to an ElementDefinition 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. If this element is present then the following element values MAY be derived from the Element Definition if the corresponding elements of this Questionnaire resource instance have no value:

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

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 a StructureDefinition 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 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 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.

Specifies the criteria by which the question is enabled.

Note that FHIR strings SHALL NOT exceed 1MB in size

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.

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.

Items are generally assumed not to be required unless explicitly specified. Systems SHOULD always populate this value

An indication, if true, that the item may occur multiple times in the response, collecting multiple 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 (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.

Items are generally assumed not to repeat unless explicitly specified. Systems SHOULD always populate this value

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.

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

Use this instead of initial[v] if answerValueSet is present.

Only selected items explicitly marked to be selected

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.