Validate FHIR resources against profiles in Azure Health Data Services
In the store profiles in the FHIR® service article, you walked through the basics of FHIR profiles and storing them. The FHIR service in Azure Health Data Services allows validating resources against profiles to see if the resources conform to the profiles. This article guides you through how to use $validate for validating resources against profiles.
$validate is an operation in Fast Healthcare Interoperability Resources (FHIR) that allows you to ensure that a FHIR resource conforms to the base resource requirements or a specified profile. This operation ensures that the data in a FHIR service has the expected attributes and values. For information on the validate operation, visit HL7 FHIR Specification.
Per specification, Mode can be specified with $validate, such as create and update:
create: FHIR service checks that the profile content is unique from the existing resources and that it's acceptable to be created as a new resource.update: Checks that the profile is an update against the nominated existing resource (that is, no changes are made to the immutable fields).
There are different ways provided for you to validate resource:
- Option 1: Validate an existing resource with the validate operation.
- Option 2: Validate a new resource with the validate operation.
- Option 3: Validate on resource CREATE or UPDATE using a header.
On the successful validation of an existing or new resource with the validate operation, the resource isn't persisted into the FHIR service. Use Option 3 to successfully persist validated resources to the FHIR service.
The FHIR service always returns an OperationOutcome as the validation results for a $validate operation. Once a resource is passed into $validate endpoint, the FHIR service does two step validation. The first step is a basic validation to ensure resource can be parsed. During resource parsing, individual errors need to be fixed before proceeding to the next step. Once a resource is successfully parsed, full validation is conducted as the second step.
Note
Any valuesets that are to be used for validation must be uploaded to the FHIR server. This includes any Valuesets which are part of the FHIR specification, as well as any ValueSets defined in implementation guides. Only fully expanded Valuesets which contain a full list of all codes are supported. Any ValueSet definitions which reference external sources are not supported.
Option 1: Validating an existing resource
To validate an existing resource, use $validate in a GET request.
GET http://<your FHIR service base URL>/{resource}/{resource ID}/$validate
For example:
GET https://myworkspace-myfhirserver.fhir.azurehealthcareapis.com/Patient/a6e11662-def8-4dde-9ebc-4429e68d130e/$validate
In this example, you're validating the existing Patient resource a6e11662-def8-4dde-9ebc-4429e68d130e against the base Patient resource. If it's valid, you get an OperationOutcome such as the following code example.
{
"resourceType": "OperationOutcome",
"issue": [
{
"severity": "information",
"code": "informational",
"diagnostics": "All OK"
}
]
}
If the resource isn't valid, you get an error code and an error message with details on why the resource is invalid. An example OperationOutcome gets returned with error messages and could look like the following code example.
{
"resourceType": "OperationOutcome",
"issue": [
{
"severity": "error",
"code": "invalid",
"details": {
"coding": [
{
"system": "http://hl7.org/fhir/dotnet-api-operation-outcome",
"code": "1028"
}
],
"text": "Instance count for 'Patient.identifier.value' is 0, which is not within the specified cardinality of 1..1"
},
"location": [
"Patient.identifier[1]"
]
},
{
"severity": "error",
"code": "invalid",
"details": {
"coding": [
{
"system": "http://hl7.org/fhir/dotnet-api-operation-outcome",
"code": "1028"
}
],
"text": "Instance count for 'Patient.gender' is 0, which is not within the specified cardinality of 1..1"
},
"location": [
"Patient"
]
}
]
}
In this example, the resource didn't conform to the provided Patient profile, which required a patient identifier value and gender.
If you'd like to specify a profile as a parameter, you can specify the canonical URL for the profile to validate against, such as the following example for the HL7 base profile for heartrate.
GET https://myworkspace-myfhirserver.fhir.azurehealthcareapis.com/Observation/12345678/$validate?profile=http://hl7.org/fhir/StructureDefinition/heartrate
Option 2: Validating a new resource
If you'd like to validate a new resource that you're uploading to the server, you can do a POST request.
POST http://<your FHIR service base URL>/{Resource}/$validate
For example:
POST https://myworkspace-myfhirserver.fhir.azurehealthcareapis.com/Patient/$validate
This request validates the resource. New resource you're specifying in the request will be created after validation.
The server always returns an OperationOutcome as the result.
Option 3: Validate on resource CREATE or UPDATE using a header
You can choose when you'd like to validate your resource, such as on resource CREATE or UPDATE. By default, the FHIR service is configured to opt out of validation on resource Create/Update. This capability allows validation on Create/Update using the x-ms-profile-validation header. Set x-ms-profile-validation to true for validation.
Note
In the open-source FHIR service, you can change the server configuration setting, under the CoreFeatures.
{
"FhirServer": {
"CoreFeatures": {
"ProfileValidationOnCreate": true,
"ProfileValidationOnUpdate": false
}
}
To enable strict validation, use a 'Prefer: handling' header with value strict. By setting this header, a validation warning is reported as an error.
Next steps
In this article, you learned how to validate resources against profiles using $validate. To learn about the other FHIR service supported features, see
Note
FHIR® is a registered trademark of HL7 and is used with the permission of HL7.