generated: '2026-09-06'
method: probed
source: >-
  GET https://clinicaltrials.gov/api/v2/studies/metadata (live, 2026-09-06, 175,633 bytes)
  cross-checked against openapi/_original/clinical-trials-gov-openapi.yml and
  https://clinicaltrials.gov/data-api/about-api/study-data-structure
note: >-
  The harvested OpenAPI declares only two schemas (Study, StudiesResponse) with
  `protocolSection` and `derivedSection` typed as bare objects, so the real data model is not
  in the contract at all — it is served, machine-readable, from GET /studies/metadata. That
  endpoint is the authoritative field dictionary and is what this artifact is derived from.
  Every entity below was read from that live response, not inferred.
primary_key:
  entity: Study
  field: protocolSection.identificationModule.nctId
  format: 'NCT followed by 8 digits (e.g. NCT00141635)'
  aliases: >-
    NCTIdAlias — historical identifiers. Since API 2.0.2, GET /studies/{nctId} redirects an
    alias to the current record.
entities:
- name: Study
  description: One registered clinical study record — the single root aggregate of the registry.
  operations:
  - GET /studies
  - GET /studies/{nctId}
  fields:
  - hasResults (boolean)
  relationships:
  - has_one: ProtocolSection
    via: protocolSection
  - has_one: ResultsSection
    via: resultsSection
    note: present only when hasResults is true
  - has_one: AnnotationSection
    via: annotationSection
  - has_one: DocumentSection
    via: documentSection
  - has_one: DerivedSection
    via: derivedSection
- name: ProtocolSection
  description: What the study intends to do — registered before or during conduct.
  relationships:
  - has_one: IdentificationModule
    via: identificationModule
    note: carries nctId, orgStudyIdInfo, secondaryIdInfos, organization, brief and official titles
  - has_one: StatusModule
    via: statusModule
    note: overallStatus, start/completion dates, last-update posting
  - has_one: SponsorCollaboratorsModule
    via: sponsorCollaboratorsModule
    note: responsibleParty, leadSponsor, collaborators[]
  - has_one: OversightModule
    via: oversightModule
  - has_one: DescriptionModule
    via: descriptionModule
  - has_one: ConditionsModule
    via: conditionsModule
  - has_one: DesignModule
    via: designModule
    note: study type, phases, enrollment, allocation/masking
  - has_one: ArmsInterventionsModule
    via: armsInterventionsModule
    note: arm groups and the interventions assigned to them
  - has_one: OutcomesModule
    via: outcomesModule
    note: primary and secondary outcome measures as specified
  - has_one: EligibilityModule
    via: eligibilityModule
  - has_one: ContactsLocationsModule
    via: contactsLocationsModule
    note: central contacts, overall officials, and locations[] (facility, city, country, geoPoint)
  - has_one: ReferencesModule
    via: referencesModule
    note: citations and links, including PubMed identifiers
  - has_one: IpdSharingStatementModule
    via: ipdSharingStatementModule
- name: ResultsSection
  description: What the study found — posted after completion, when results were submitted.
  relationships:
  - has_one: ParticipantFlowModule
    via: participantFlowModule
  - has_one: BaselineCharacteristicsModule
    via: baselineCharacteristicsModule
  - has_one: OutcomeMeasuresModule
    via: outcomeMeasuresModule
    note: reported outcomes with measurement and statistical-analysis tables
  - has_one: AdverseEventsModule
    via: adverseEventsModule
  - has_one: MoreInfoModule
    via: moreInfoModule
- name: AnnotationSection
  description: Registry annotations attached to the record.
  relationships:
  - has_one: AnnotationModule
    via: annotationModule
- name: DocumentSection
  description: Uploaded study documents (protocol, statistical analysis plan, informed consent form).
  relationships:
  - has_many: LargeDocument
    via: documentSection.largeDocumentModule.largeDocs
- name: DerivedSection
  description: Fields NLM computes rather than receives from the sponsor.
  relationships:
  - has_one: MiscInfoModule
    via: miscInfoModule
  - has_one: BrowseModule
    via: conditionBrowseModule
    note: MeSH condition terms derived from the record
  - has_one: BrowseModule
    via: interventionBrowseModule
    note: MeSH drug/intervention terms derived from the record
external_identifier_domains:
- name: NCT number
  field: protocolSection.identificationModule.nctId
  authority: ClinicalTrials.gov / NLM
- name: MeSH terms
  field: derivedSection.conditionBrowseModule / interventionBrowseModule
  authority: NLM Medical Subject Headings
- name: PubMed ID
  field: protocolSection.referencesModule.references[].pmid
  authority: NLM PubMed
- name: Organization study ID
  field: protocolSection.identificationModule.orgStudyIdInfo.id
  authority: the sponsoring organization
- name: FHIR ResearchStudy
  field: 'whole record, via ?format=fhir.json'
  authority: HL7 — profile http://hl7.org/fhir/uv/ebm/StructureDefinition/study-registry-record
enumerations:
  endpoint: GET /studies/enums
  note: controlled vocabularies for status, phase, study type, sex, age group and similar fields
search_areas:
  endpoint: GET /studies/search-areas
  docs: https://clinicaltrials.gov/data-api/about-api/search-areas
  note: the named areas the query.* parameters target; required to build a non-trivial query
render: null
render_note: no subway/ diagram exists in this repo