Retrieving the patient's ehrId
When a patient is registered with a CDR, by supplying their 'subjectId (normally a real-word identifier like an NHS number, CHI number or hospital MRI), a top-level EHR object is created in the datastore along with a unique identifier for that patient.
Most of the CDR API calls require an 'ehrId' to identify the correct patient ,so normally the first activity required if interacting with a patient record is to retrieve their ehrId.
Better Ehrscape GET /ehr - Get ehrStatus from SubjectId example
Parameters
subjectId
This is the external identifier by which the patient is known within the CDR. It is normally a real-word identifier like an NHS number, CHI number or Hospital 'MRI' number, and will have been supplied to the CDR when the patients' EHR object was created in the datastore.
Example value : 9999999000
subjectNamespace
This is just a unique string used to identify the numbering scheme used for the 'subjectId'. It will commonly be some sort of URI such as uk.nhs.nhs_number and will have been agreed at national level.
Example value : uk.nhs.nhs_number
curl --location \
--request GET 'https://cdr.code4health.org/rest/v1/ehr/?subjectId=9999999000&subjectNamespace=uk.nhs.nhs_number' \
--header 'Content-Type: application/json' \
--header 'Authorization: Basic YTgxZjQ3YzYtYTc1Ny00ZTM0LWI2NDQtM2NjYzYyYjRhMDFjOiQyYSQxMCQ2MTlraQ=='
var axios = require('axios');
var config = {
method: 'get',
url: 'https://cdr.code4health.org/rest/v1/ehr/?subjectId=9999999000&subjectNamespace=uk.nhs.nhs_number',
headers: {
'Content-Type': 'application/json',
'Authorization': 'Basic YTgxZjQ3YzYtYTc1Ny00ZTM0LWI2NDQtM2NjYzYyYjRhMDFjOiQyYSQxMCQ2MTlraQ=='
}
};
axios(config)
.then(function (response) {
console.log(JSON.stringify(response.data));
})
.catch(function (error) {
console.log(error);
});
import requests
url = "https://cdr.code4health.org/rest/v1/ehr/?subjectId=9999999000&subjectNamespace=uk.nhs.nhs_number"
payload = {}
headers = {
'Content-Type': 'application/json',
'Authorization': 'Basic YTgxZjQ3YzYtYTc1Ny00ZTM0LWI2NDQtM2NjYzYyYjRhMDFjOiQyYSQxMCQ2MTlraQ==',
}
response = requests.request("GET", url, headers=headers, data = payload)
print(response.text.encode('utf8'))
Response
Better CDR will give a 200 response code and this structure.
{
"meta": {
"href": "https://cdr.code4health.org/rest/v1/ehr/3e674739-950c-4b8a-976b-5aef21c618c5"
},
"ehrStatus": {
"subjectId": "9999999000",
"subjectNamespace": "uk.nhs.nhs_number",
"queryable": true,
"modifiable": true,
"otherDetails": {
"@class": "ITEM_TREE",
"items": [
{
"@class": "CLUSTER",
"archetype_details": {
"@class": "ARCHETYPED",
"archetype_id": {
"@class": "ARCHETYPE_ID",
"value": "openEHR-EHR-CLUSTER.person_anonymised_parent.v1"
},
"rm_version": "1.0.1"
},
"archetype_node_id": "openEHR-EHR-CLUSTER.person_anonymised_parent.v1",
"items": [
{
"@class": "ELEMENT",
"name": {
"@class": "DV_TEXT",
"value": "Administrative Gender"
},
"archetype_node_id": "at0001",
"value": {
"@class": "DV_CODED_TEXT",
"value": "Male",
"defining_code": {
"@class": "CODE_PHRASE",
"terminology_id": {
"@class": "TERMINOLOGY_ID",
"value": "local"
},
"code_string": "at0009"
}
}
},
{
"@class": "ELEMENT",
"name": {
"@class": "DV_TEXT",
"value": "Birth Sex"
},
"archetype_node_id": "at0002",
"value": {
"@class": "DV_CODED_TEXT",
"value": "Male",
"defining_code": {
"@class": "CODE_PHRASE",
"terminology_id": {
"@class": "TERMINOLOGY_ID",
"value": "local"
},
"code_string": "at0009"
}
}
},
{
"@class": "ELEMENT",
"name": {
"@class": "DV_TEXT",
"value": "Vital Status"
},
"archetype_node_id": "at0003",
"value": {
"@class": "DV_CODED_TEXT",
"value": "Alive",
"defining_code": {
"@class": "CODE_PHRASE",
"terminology_id": {
"@class": "TERMINOLOGY_ID",
"value": "local"
},
"code_string": "at0004"
}
}
},
{
"@class": "ELEMENT",
"name": {
"@class": "DV_TEXT",
"value": "Birth Year"
},
"archetype_node_id": "at0014",
"value": {
"@class": "DV_DATE",
"value": "1944"
}
}
]
}
]
}
},
"ehrId": "3e674739-950c-4b8a-976b-5aef21c618c5"
}
The only datapoint you need to retrieve is ehrId.
Hint
You may want to consider caching this for the session, so that it can be used for a number of subsequent calls.