ResearchStudy.enrollment Inconsistencies b/t dbGap, KidsFirst and AnVIL

[bwalsh]

The following queries will produce a Bundle of ResearchStudy and all its subjects:

• https://healthcare.googleapis.com/v1beta1/projects/fhir-test-11-329119/locations/us-west2/datasets/anvil-test/fhirStores/public/fhir/ResearchStudy?_id=1000G-high-coverage-2019&_revinclude=ResearchSubject:study
• https://kf-api-fhir-service.kidsfirstdrc.org/ResearchStudy?_id=76758&_revinclude=ResearchSubject
• https://dbgap-api.ncbi.nlm.nih.gov/fhir/x1/ResearchStudy?_id=phs002409&_revinclude=ResearchSubject:study

However, only dbGap will return a populated enrollment field

  "enrollment": [ {
        "reference": "Group/phs002409.v1.p1-all-subjects"
      } ]

Which in turn points to enrollment description

{
  "resourceType": "Group",
  "id": "phs002409.v1.p1-all-subjects",
  "meta": {
    "versionId": "1",
    "lastUpdated": "2021-11-04T03:02:17.853-04:00",
    "source": "#RE1Du0b0kHjND2mT"
  },
  "text": {
    "status": "additional",
    "div": "<div xmlns=\"http://www.w3.org/1999/xhtml\"><p>Simulated data to be used for FHIR testing</p><dl><dt>Actual</dt><dd>True</dd><dt>Active</dt><dd>True</dd><dt>Name</dt><dd>All subjects in phs002409.v1.p1</dd><dt>Total Subjects</dt><dd>813</dd></dl></div>"
  },
  "active": true,
  "type": "person",
  "actual": true,
  "name": "All subjects in phs002409.v1.p1",
  "quantity": 813
}```