How to tell which study an observation belongs to?

What were you reviewing?

Thanks for the very nice IG!

We have tried querying Observation entries with examples like https://fhir.immport.org/fhir/Observation?code =FEV. We received good records like the one below. However, our question is whether it is possible to link an Observation to a ResearchStudy from which the observation value belongs to.

We also tried the KidsFirst FHIR server and noticed that their Observation entry includes the study in the meta tag( example below). This provides a way to link the Observation to the study it originates from. As we know, the FHIR Observation resource links to Patient, but not to ResearchSubject. Including the study identifier in the meta tag seems like a useful workaround.

In dbGaP, the same individual can be enrolled in completely different studies (not merely parent and sub-studies). Additionally, the same person in different studies can have distinct "observed" values for equivalent phenotypic measures. Therefore, it’s crucial to be able to link an Observation to the specific study it came from. dbGaP uses "study-specific phenotype variable (phv)" as a way to link an Observation to a study ( see example below). However, we are open to exploring the KidsFirst approach of adding the study tag in the meta tag of Observation.

We would appreciate your insights on this matter. We hope this issue helps gather feedback and action items. Thank you!

ImmPort Observation: https://fhir.immport.org/fhir/Observation?code:text=FEV

      "fullUrl": "https://fhir.immport.org/fhir/Observation/AC1008266",
      "resource": {
        "resourceType": "Observation",
        "id": "AC1008266",
        "meta": {
          "versionId": "1",
          "lastUpdated": "2024-08-20T20:27:26.622+00:00",
          "source": "#y65tBnozgEScRbOB"
        },
        "status": "final",
        "code": {
          "text": "FEV1"
        },
        "subject": {
          "reference": "Patient/SUB177364"
        },
        "valueQuantity": {
          "value": 67.0,
          "unit": "percentage"
        }
      },
   ''''
    },

KidsFirst bservation: https://kf-api-fhir-service.kidsfirstdrc.org

....
'meta': {'lastUpdated': '2024-03-21T04:29:24.739+00:00',
                                  'profile': ['http://hl7.org/fhir/StructureDefinition/Observation'],
                                  'source': '#jKvj1uSqAwaBZMAC',
                                  'tag': [{'code': 'SD_65064P2Z',
                                           'system': 'https://kf-api-dataservice.kidsfirstdrc.org/studies/'}],
                                  'versionId': '1'},
....

dbGaP example Observation (synthetic data server): https://dbgap-api.ncbi.nlm.nih.gov/fhir-jpa-pilot/x1/Observation?code:text=FEV&_count=2 note: phv00508498 can be used to find the specific study it is from.

...
"fullUrl": ["https://dbgap-api.ncbi.nlm.nih.gov/fhir-jpa-pilot/x1/Observation/508498-4317771-0"](https://dbgap-api.ncbi.nlm.nih.gov/fhir-jpa-pilot/x1/Observation/508498-4317771-0),
    "resource": {
      "resourceType": "Observation",
      "id": "508498-4317771-0",
      "meta": {
        "versionId": "1",
        "lastUpdated": "2024-09-23T14:32:29.126-04:00",
        "source": "#d11zIyz0o1EY2FQF",
        "security": [ {
          "system": ["http://terminology.hl7.org/CodeSystem/v3-Confidentiality"](http://terminology.hl7.org/CodeSystem/v3-Confidentiality),
          "code": "U",
          "display": "unrestricted"
        } ]
      },
      "status": "final",
      "code": {
        "coding": [ {
          "system": ["https://dbgap-api.ncbi.nlm.nih.gov/fhir/x1/CodeSystem/DbGaPConcept-VariableAccession"](https://dbgap-api.ncbi.nlm.nih.gov/fhir/x1/CodeSystem/DbGaPConcept-VariableAccession),
          "code": "phv00508498.v1.p1",
          "display": "FEV1_PRED_SCR"
        } ]
      },
      "subject": {
        "reference": ["Patient/4317771"](https://dbgap-api.ncbi.nlm.nih.gov/fhir-jpa-pilot/x1/Patient/4317771)
      },
      "valueQuantity": {
        "value": 2.44911795,
        "unit": "%"
      }
    },

Thank you for looking at this!

NIH-NCPI / ncpi-fhir-ig-2