--- description: This article outlines operations from the FHIR SDC Implementation Guide. --- # FHIR SDC API > Implementation corresponds to [SDC FHIR IG - 3.0.version 0](http://hl7.org/fhir/uv/sdc/) ## FHIR SDC API Aidbox Forms module supports FHIR SDC operations: * [$populate](fhir-sdc-api.md#populate-questionnaire-populate) - filling out a form with existing data ([FHIR](https://hl7.org/fhir/uv/sdc/OperationDefinition-Questionnaire-populate.html)) * [$populatelink](fhir-sdc-api.md#populate-questionnaire-and-generate-a-link-populatelink) - filling out a form with existing data, and return signed link to it ([FHIR](https://hl7.org/fhir/uv/sdc/OperationDefinition-Questionnaire-populatelink.html)) * [$extract](fhir-sdc-api.md#questionnaire-response-extract-to-resources-extract) - extract data from QuestionnaireResponse to other FHIR resources ([FHIR](https://hl7.org/fhir/uv/sdc/OperationDefinition-QuestionnaireResponse-extract.html)) * [$expand](fhir-sdc-api.md#valueset-expansion-expand) - create a simple collection of codes suitable for use for data entry or validation. ([FHIR](https://www.hl7.org/fhir/valueset-operation-expand.html)) > We have created an [Aidbox notebook](../../overview/aidbox-ui/README.md) demonstrating different population and extraction methods: > > [**Aidbox forms: populate & extract**](https://aidbox.app/ExportedNotebook/10b1ea71-8e25-4f5e-aaff-e64ae50a27d5) ## Populate Questionnaire - $populate The [populate](https://hl7.org/fhir/uv/sdc/OperationDefinition-Questionnaire-populate.html) operation generates a [QuestionnaireResponse](https://www.hl7.org/fhir/questionnaireresponse.html) based on a specific [Questionnaire](https://www.hl7.org/fhir/questionnaire.html), filling in answers to questions where possible based on information provided as part of the operation or already known by the server about the subject of the Questionnaire. > This implementation supports the [Observation based](https://hl7.org/fhir/uv/sdc/populate.html#observation-based-population) and [Expression based](https://hl7.org/fhir/uv/sdc/populate.html#expression-based-population) population methods. ### URLs ``` POST [base]/fhir/Questionnaire/$populate ``` ``` POST [base]/fhir/Questionnaire/[id]/$populate ``` ### Parameters | Parameter | Cardinality | Type | Status | | ---------------------------------------------------- | ----------- | ---------------------------------------------------------------- | --------------- | | [identifier](fhir-sdc-api.md#identifier) | 0..1 | [Identifier](http://hl7.org/fhir/R4/datatypes.html#Identifier) | `supported` | | [canonical](fhir-sdc-api.md#canonical) | 0..1 | [uri](http://hl7.org/fhir/R4/datatypes.html#uri) | `supported` | | [questionnaire](fhir-sdc-api.md#questionnaire) | 0..1 | [Questionnaire](http://hl7.org/fhir/R4/questionnaire.html) | `supported` | | [questionnaireRef](fhir-sdc-api.md#questionnaireref) | 0..1 | [Reference](http://hl7.org/fhir/R4/references.html#Reference) | `supported` | | [subject](fhir-sdc-api.md#subject) | 1..1 | [Reference](http://hl7.org/fhir/R4/references.html#Reference) | `supported` | | [context](fhir-sdc-api.md#context) | 0..\* | [Reference](http://hl7.org/fhir/R4/references.html#Reference) | `supported` | | [context.name](fhir-sdc-api.md#context.name) | 1..1 | [string](https://www.hl7.org/fhir/datatypes.html#string) | `supported` | | [context.content](fhir-sdc-api.md#context.content) | 1..\* | [Reference](http://hl7.org/fhir/R4/references.html#Reference) | `supported` | | [local](fhir-sdc-api.md#local) | 0..1 | [boolean](http://hl7.org/fhir/R4/datatypes.html#boolean) | `supported` | | [launchContext](fhir-sdc-api.md#launchcontext) | 0..1 | [Extension](http://hl7.org/fhir/R4/extensibility.html#Extension) | `not supported` | > Parameters are specified via FHIR [Parameters](https://www.hl7.org/fhir/parameters.html#parameters) type. Example ```yaml resourceType: Parameters parameter: - name: subject valueReference: reference: Patient/pt-1 ``` #### identifier A logical questionnaire identifier (i.e. Questionnaire.identifier). The server must know the questionnaire or be able to retrieve it from other known repositories. ```yaml name: identifier valueIdentifier: system: 'forms.aidbox' value: 'vitals' ``` #### canonical The canonical identifier for the questionnaire (optionally version-specific). ```yaml name: canonical valueCanonical: http://forms.aidbox.io/Questionnaire/vitals ``` #### questionnaire The Questionnaire is provided directly as part of the request. Servers may choose not to accept questionnaires in this fashion ```yaml name: questionnaire resource: resourceType: Questionnaire id: new-form title: "Vitals" ... ``` #### questionnaireRef The Questionnaire is provided as a resource reference. Servers may choose not to accept questionnaires in this fashion or may fail if they cannot resolve or access the referenced questionnaire. ```yaml name: questionnaireRef valueReference: resourceType: Questionnaire id: new-form ``` #### subject The resource that is to be the QuestionnaireResponse.subject. The QuestionnaireResponse instance will reference the provided subject. In addition, if the local parameter is set to true, server information about the specified subject will be used to populate the instance. ```yaml name: subject valueReference: reference: Patient/pt-1 ``` #### local If specified and set to true (and the server is capable), the server should use what resources and other knowledge it has about the referenced subject when pre-populating answers to questions. ```yaml name: local valueBoolean: true ``` #### context Resources containing information to be used to help populate the QuestionnaireResponse. These will typically be FHIR resources. Context paramertes are presented as pairs of `name` and `content` parameters that are placed under the `part` key. They should correspond launchContext parameter definitions. ```yaml name: context part: - name: name valueString: encounter - name: content valueReference: reference: Encounter/enc1 ``` FHIR SDC launchContext extension [enumerates](http://hl7.org/fhir/uv/sdc/STU3/CodeSystem-launchContext.html) possible context variables, they are: | Code | Type | Definition | | --------- | ----------------------------------------------------------------------------------------------------------------------------------------------------- | ----------------------------------------- | | patient | [Reference](http://hl7.org/fhir/R4/references.html#Reference)/resource | Patient Patient in context at launch time | | encounter | [Reference](http://hl7.org/fhir/R4/references.html#Reference)/resource | Encounter context at launch time | | location | [Reference](http://hl7.org/fhir/R4/references.html#Reference)/resource | Location context at launch time | | user | [Reference\](http://hl7.org/fhir/R4/references.html#Reference)/resource | User in context at launch time | | study | [Reference](http://hl7.org/fhir/R4/references.html#Reference)/resource | ResearchStudy in context at launch time | Additionnaly Aidbox expands this list with parameters that mirrors [QuestionnaireResponse](https://hl7.org/fhir/R4/questionnaireresponse.html) root properties. {% hint style="warning" %} WARN: This is non FHIR SDC compliant behavior! Paramerters passed directly to [QuestionnaireResponse](https://hl7.org/fhir/R4/questionnaireresponse.html) root properties and should not be used in populate expressions. {% endhint %} | Code | Type | | ---------- | -------------------------------------------------------------------------------------------------------------------------------------------- | | identifier | [Identifier](http://hl7.org/fhir/R4/datatypes.html#Identifier) | | basedOn | [Reference\](http://hl7.org/fhir/R4/references.html#Reference) | | partOf | [Reference\](http://hl7.org/fhir/R4/references.html#Reference) | | encounter | [Reference\](http://hl7.org/fhir/R4/references.html#Reference) | | author | [Reference\](http://hl7.org/fhir/R4/references.html#Reference) | | source | [Reference\](http://hl7.org/fhir/R4/references.html#Reference) | Example: ```yaml name: name valueReference: reference: ServiceRequest/sr1 ``` #### context.name The name of the launchContext or root Questionnaire variable the passed content should be used as for population purposes. The name SHALL correspond to a launchContext or variable delared at the root of the Questionnaire. ```yaml name: name valueString: encounter ``` #### context.content The actual resource (or resources) to use as the value of the launchContext or variable. ```yaml name: content valueReference: reference: Encounter/enc1 ``` Or ```yaml name: content resource: ... resourceType: Encounter id: enc1 subject: reference: Patient/pt-1 ... ``` #### launchContext Resources that provide context for form processing logic (pre-population) when creating/displaying/editing a QuestionnaireResponse. ### Response * in failure case - response is specified as [OperationOutcome](https://hl7.org/fhir/R4/operationoutcome.html) object. * in success case - response is specified as [Parameters](https://www.hl7.org/fhir/parameters.html#parameters) object. Success response shape | Parameter | Cardinality | Type | Description | | --------- | ----------- | --------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------- | | response | 1..1 | [QuestionnaireResponse](https://hl7.org/fhir/R4/questionnaireresponse.html) | The partially (or fully)-populated set of answers for the specified Questionnaire | | issues | 0..1 | [OperationOutcome](https://hl7.org/fhir/R4/operationoutcome.html) | A list of hints and warnings about problems encountered while populating the questionnaire. | ### Usage Example {% tabs %} {% tab title="Request" %} ```http POST [base]/fhir/Questionnaire/vitals/$populate content-type: text/yaml resourceType: Parameters parameter: - name: subject valueReference: reference: Patient/pt-1 - name: context part: - name: name valueString: encounter - name: content valueReference: reference: Encounter/enc1 ``` {% endtab %} {% tab title="Success Response" %} HTTP status: 200 ```yaml resourceType: Parameters parameter: - name: response resource: resourceType: QuestionnaireResponse questionnaire: http://aidbox.app/forms/new-form status: in-progress basedOn: reference: ServiceRequest/sr1 encounter: reference: Encounter/enc1 item: - linkId: name text: Name - linkId: weight ``` {% endtab %} {% tab title="Failure Response" %} HTTP status: 422 ```yaml resourceType: OperationOutcome text: status: generated div: Parameters are invalid issue: - severity: error code: invalid expression: - parameter.0.resource diagnostics: unknown key :resource ``` {% endtab %} {% endtabs %} ## Populate Questionnaire and generate a link - $populatelink The [populatelink](https://hl7.org/fhir/uv/sdc/OperationDefinition-Questionnaire-populatelink.html) operation generates a link to a web page to be used to answer a specified [Questionnaire](https://www.hl7.org/fhir/questionnaire.html). The form at the specified location will be pre-filled with answers to questions where possible based on information provided as part of the operation or already known by the server about the subject of the Questionnaire. ### URLs ``` POST [base]/fhir/Questionnaire/$populatelink ``` ``` POST [base]/fhir/Questionnaire/[id]/$populatelink ``` ### Parameters The base set of parameters is the same as for [$populate](fhir-sdc-api.md#parameters). On top of that, a few extra parameters are supported by Aidbox Forms. {% hint style="warning" %} WARN: The following parameters are not FHIR SDC compliant. This is an extension of the specification. {% endhint %} {% hint style="warning" %} NOTE: Don't forget to wrap parameters in `Parameters object` ```yaml resourceType: Parameters parameter: - name: [var-name] valueX: [varType: var-value] ``` {% endhint %} | Parameter | Cardinality | Type | | -------------------------------------------------------- | ----------- | -------------------------------------------------------- | | [allow-amend](fhir-sdc-api.md#allow-amend) | 0..1 | [Boolean](http://hl7.org/fhir/R4/datatypes.html#boolean) | | [allow-repopulate](fhir-sdc-api.md#allow-repopulate) | 0..1 | [Boolean](http://hl7.org/fhir/R4/datatypes.html#boolean) | | [redirect-on-submit](fhir-sdc-api.md#redirect-on-submit) | 0..1 | [String](http://hl7.org/fhir/R4/datatypes.html#string) | | [redirect-on-submit](fhir-sdc-api.md#redirect-on-submit) | 0..1 | [String](http://hl7.org/fhir/R4/datatypes.html#string) | | [expiration](fhir-sdc-api.md#link-expiration-time) | 0..1 | [Integer](http://hl7.org/fhir/R4/datatypes.html#integer) | | [theme](fhir-sdc-api.md#theme) | 0..1 | [String](http://hl7.org/fhir/R4/datatypes.html#string) | | [config](fhir-sdc-api.md#config) | 0..1 | [String](http://hl7.org/fhir/R4/datatypes.html#string) | | [read-only](fhir-sdc-api.md#read-only) | 0..1 | [Boolean](http://hl7.org/fhir/R4/datatypes.html#boolean) | | [app-name](fhir-sdc-api.md#read-only) | 0..1 | [String](http://hl7.org/fhir/R4/datatypes.html#string) | #### allow-amend Whether the generated link will allow amending and re-submitting the form. ``` name: allow-amend valueBoolean: true ``` #### allow-repopulate Whether the generated link will allow re-populating the form. NOTE: Repopulate will be working only with forms that contain populate behavior ``` name: allow-repopulate valueBoolean: true ``` #### redirect-on-submit A URL where the user will be redirected to after successfully submitting the form. ```yaml name: redirect-on-submit valueString: https://example.com/submit-hook?questionnaire=123 ``` #### redirect-on-save A URL where the user will be redirected to after hitting Save button. > By default `Save button is not visible` - form autosaved after every keystroke. But sometimes it's usefull to close form in a partially-filled state ```yaml name: redirect-on-save valueString: https://example.com/submit-hook?questionnaire=123 ``` #### link expiration time Link expiration period (days) ```yaml name: expiration valueInteger: 30 ``` > By default thir parameter = 7 days #### theme Form theme. QuestionnaireTheme resource id. ```yaml name: theme valueString: hs-theme ``` #### config Form config. SDCConfig resource id. ```yaml name: theme valueString: default-config ``` #### read-only Open form in read-only mode. ```yaml name: read-only valueBoolean: true ``` #### app-name Application name that will be used in Audit logging when returned link was used. > Audit logging should be enabled. ```yaml name: app-name valueString: my-app ``` ### Response * in failure case - response is specified as [OperationOutcome](https://hl7.org/fhir/R4/operationoutcome.html) object containing a link. * in success case - response is specified as [Parameters](https://www.hl7.org/fhir/parameters.html#parameters) object containing a list of issues. | Parameter | Cardinality | Type | Description | | --------- | ----------- | ----------------------------------------------------------------- | ------------------------------------------------------------------------------------------ | | link | 1..1 | [uri](http://hl7.org/fhir/R4/datatypes.html#uri) | The URL for the web form that supports capturing the information defined by questionnaire | | issues | 0..1 | [OperationOutcome](https://hl7.org/fhir/R4/operationoutcome.html) | A list of hints and warnings about problems encountered while populating the questionnaire | ### Usage Example {% tabs %} {% tab title="Request" %} ```http POST [base]/fhir/Questionnaire/vitals/$populatelink content-type: text/yaml resourceType: Parameters parameter: - name: subject valueReference: reference: Patient/pt-1 - name: context part: - name: name valueString: encounter - name: content resource: resourceType: Encounter id: enc-1 subject: reference: Patient/pt-1 ``` {% endtab %} {% tab title="Success Response" %} HTTP status: 200 ```yaml resourceType: Parameters parameter: - name: link valueUri: http://forms.aidbox.io/ui/sdc#/questionnaire-response/12c1178c-70a9-4e02-a53d-65b13373926e?token=eyJhbGciOiJIUzI ``` {% endtab %} {% tab title="Failure Response" %} HTTP status: 422 ```yaml resourceType: OperationOutcome text: status: generated div: Parameters are invalid issue: - severity: error code: invalid expression: - parameter.0.resource diagnostics: unknown key :resource ``` {% endtab %} {% endtabs %} ## Questionnaire response extract to resources - $extract The [extract](http://hl7.org/fhir/uv/sdc/OperationDefinition/QuestionnaireResponse-extract) operation takes a completed `QuestionnaireResponse` and extracts it's data to `Bundle` of resources by using metadata embedded in the `Questionnaire` the `QuestionnaireResponse` is based on. The extracted resources might include `Observations`, MedicationStatements and other standard FHIR resources which can then be shared and manipulated. Aidbox supports only the [Observation based](https://hl7.org/fhir/uv/sdc/extraction.html#observation-based-extraction) and [Definition based](https://hl7.org/fhir/uv/sdc/extraction.html#definition-based-extraction) extraction methods. {% hint style="info" %} Current Logic for **Observation-based** extraction: * A new Observation is created for each Questionnaire Response instance at the time of data extraction. * If a QR is amended (modified after submission), the existing Observations linked to that QR are updated accordingly. In the future, Aidbox Forms will align with the implementation described in the [FHIR Structured Data Capture (SDC) specification](https://build.fhir.org/ig/HL7/sdc/extraction.html#observation-based-extraction). {% endhint %} {% hint style="info" %} Current Logic for **Definition-based extraction**: * Two Options for Resource Extraction: * **New Resource**: If "new resource" is selected, a new resource is always created during extraction. * **Existing Resource:** If "existing resource" is selected, the system includes the `questionnaire-itemExtractionContext` extension. This extension can be added either at the root of the Questionnaire or at any item level. It identifies the resource that serves as the context for extraction. Using `itemExtractionContext`: * Empty `itemExtractionContext`: When the `itemExtractionContext` is empty, the Questionnaire is used to create a new resource. * Populated `itemExtractionContext`: If the `itemExtractionContext` contains a resource (or set of resources), the Questionnaire updates the existing resource. {% endhint %} ### URLs ```http URL: [base]/fhir/QuestionnaireResponse/$extract ``` ``` URL: [base]/fhir/QuestionnaireResponse/[id]/$extract ``` ### Parameters | Parameter | Cardinality | Type | Description | | ---------------------- | ----------- | ------------------------------------------------ | ----------------------------------------------- | | questionnaire-response | 0..1 | [Resourse](http://hl7.org/fhir/R4/resource.html) | The QuestionnaireResponse to extract data from. | > Parameters are specified via FHIR [Parameters](https://www.hl7.org/fhir/parameters.html#parameters) type. Example ```yaml resourceType: Parameters parameter: - name: questionnaire-response resource: id: qr-1 resourceType: QuestionnaireResponse ... ``` ### Response * in failure case - response is specified as [OperationOutcome](https://hl7.org/fhir/R4/operationoutcome.html) object. * in success case - response is specified as [Parameters](https://www.hl7.org/fhir/parameters.html#parameters) object. | Parameter | Cardinality | Type | Description | | --------- | ----------- | ----------------------------------------------------------------- | --------------------------------------------------------------------------------- | | return | 1..1 | [Resourse](http://hl7.org/fhir/R4/resource.html) | FHIR Bundle with extracted resources | | issues | 0..1 | [OperationOutcome](https://hl7.org/fhir/R4/operationoutcome.html) | A list of hints and warnings about problems encountered while extracting the data | ### Usage Example {% tabs %} {% tab title="Request" %} ```http POST [base]/fhir/QuestionnaireResponse/$extract content-type: text/yaml resourceType: Parameters parameter: - name: questionnaire-response resource: id: pt-1 resourceType: QuestionnaireResponse questionnaire: https://forms.aidbox.io/vitals item: - linkId: temperature valueDecimal: 36.6 ... ``` {% endtab %} {% tab title="Success Response" %} HTTP status: 200 ```yaml return: resourceType: Bundle type: transaction entry: - resource: resourceType: Observation status: final code: coding: - code: body-temperature system: loinc subject: reference: Patient/pt-1 valueQuantity: unit: [c] value: 36.6 request: {method: POST, url: /Observation} ``` {% endtab %} {% tab title="Failure Response" %} HTTP status: 422 ```yaml resourceType: OperationOutcome text: status: generated div: Parameters are invalid issue: - severity: error code: invalid expression: - parameter.0.resource.given diagnostics: unknown key :given ``` {% endtab %} {% endtabs %} ## ValueSet Expansion - $expand Value Sets are used to define possible coded answer choices in a questionnaire. The use of standardized codes is useful when data needs to be populated into the questionnaire or extracted from the questionnaire for other uses. The `expand` operation expand given ValueSet in to set of concepts. This operation is described in detail [here](../../deprecated/deprecated/other/terminology/valueset/valueset-expansion.md).