Search CGM Observation by parameters

A client can search for CGM Observations by using the GET method on the server's Observation endpoint with the following query parameters:

subject parameter

The subject parameter MUST be provided with the external Patient id of the patient whose Observations are being queried. The patient id must follow the FHIR specified format for id

Validation of dates

In the query parameters, it is mandatory to include either date or _lastUpdated, both parameters included simultaneously are also allowed. The following validation rules are applied to both date and _lastUpdated parameters:

1. There must be exactly 2 dates separated by a comma. Start date should be less than the end date.
2. Start date should have prefix ge
3. End date should have prefix le
4. Date format should be [ge|le]yyyy-MM-ddTHH:MM:SS[+|-]HH:MM
5. Currently supported search is for a MAX duration of 90Days

Validation of _sort parameter

The current supported values for parameter _sort are date for ascending order of date and -date for descending order. By default, the response is sorted in descending order of effective dates.

Example

curl -sS "https://${server}/${basePath}/Observation?subject=EA3yxWmZP58GR8vansmBVpdx2URdsJM&date=ge2024-09-01T00%3A00%3A00Z&date=le2024-09-14T00%3A00%3A00Z&code=434910001&_lastUpdated=ge2025-09-01T00%3A00%3A00Z&_lastUpdated=le2025-09-02T00%3A00%3A00Z&_sort=date" \
  -H "client_id: ${client_id}" \
  -H "client_secret: ${client_secret}" \
  -H "org_id: ${org_id}" \
  -H "certificate: ${certificate}" | jq

This request searches for CGM Observations (code 434910001) for the patient with the ID EA3yxWmZP58GR8vansmBVpdx2URdsJM whose effective date time is greater than 2024-09-01T00:00:00 and less than 2024-09-14T00:00:00 and whose last updated time is greater than 2025-09-01T00:00:00 and less than 2025-09-02T00:00:00. The Response observations are sorted in ascending order of date.

Response

The server responds with a Bundle of type searchset resource containing the matching Observation resources. The response is paginated and contains a link field with the URL to the next page of results, if any.

Example

This is a sample CGM search result for a given external Patient ID. The search result contains 4 CGM Observation collected between time period 02/10/2023 02:00:00 and 02/10/2023 02:15:00 at an interval of 5 minutes apart.

The response contains a single Observation resource with the ID 1 that represents a CGM Observation for the patient with the ID EA3yxWmZP58GR8vansmBVpdx2URdsJM between 2024-09-01 and 2024-09-14. The Observation resource is described by the CGM_OBSERVATION Profile

Description of the Sample

Other Use Cases

This section collects a series of scenarios where some variation may happen with respect to the default sample presented previously.

Response for missing data

Situations like failure of the sensor, or momentary loss of network connection from the patch, would cause the amount of values inside entry.resource.valueSampledData.data to decrease from what would be there in a normal scenario. Furthermore, both the timestamps and offsets found in entry.resource.valueSampledData.extension (ext-SampledDataTimestamps) and entry.resource.valueSampledData.offsets would reflect this gap in transmitted data. The relationship between these and the actual data would still be 1 to 1, but the difference between one offset/timestamp item and the next would be higher than the regular period, showing the mentioned transmission gap.

{
	"valueSampledData": {
		"extension":  [
			{
				"url": "https://roche.com/fhir/iop/StructureDefinition/ext-CGMFlags",
				"valueString": "HI; NULL; LO; LO"
			},
			{
				"url": "https://roche.com/fhir/iop/StructureDefinition/ext-SampledDataTimestamps",
				"valueString": "2023-02-10T02:00:00+00:00 2023-02-10T02:05:00+00:00 2023-02-10T02:15:00+00:00 2023-02-10T02:20:00+00:00"
			}
		],
		"origin": {
			"value": 0,
			"unit": "mg/dL",
			"system": "http://unitsofmeasure.org",
			"code": "mg/dL"
		},
		"intervalUnit": "s",
		"dimensions": 1,
		"offsets": "0 300.0 900.0 1200.0",
		"data": "163 158 98 98"
	}
}