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National Institutes of Health (NIH)

National Institutes of Health (NIH) Studies API

Related to clinical trial studies

Documentation Provider Profile APIs.io OpenAPI GitHub

National Institutes of Health (NIH) Studies API is one of 15 APIs that National Institutes of Health (NIH) publishes on the APIs.io network, described by a machine-readable OpenAPI specification.

Tagged areas include Studies. The published artifact set on APIs.io includes an OpenAPI specification and API documentation.

This API exposes 5 operations across 5 paths, and defines 144 schemas. It is described by OpenAPI 3.2.0, at version 2.0.5.

Requests are made against a single base URL, https://clinicaltrials.gov/api/v2.

5 operations 5 paths 144 schemas 5 GET

Metadata

The identity and technical contract details declared by the specification.

Specification
OpenAPI 3.2.0
API Version
2.0.5
Base URL
https://eutils.ncbi.nlm.nih.gov/entrez/eutils/
Resource Areas
1

Paths & Operations 5

Across 5 paths, the API surfaces 5 operations — 5 GET. Each is listed below with its method, path, parameters, and response codes.

Studies 5

Related to clinical trial studies

GET
/studies
Studies
listStudies 29 params → 200400
GET
/studies/{nctId}
Single Study
fetchStudy 4 params → 200301400404
GET
/studies/metadata
Data Model Fields
studiesMetadata 2 params → 200400
GET
/studies/search-areas
Search Areas
searchAreas → 200400
GET
/studies/enums
Enums
enums → 200400

Schemas 144

The contract defines 144 schemas that model the data the API accepts and returns. The most detailed are StatusModule (21 properties), MeasureAnalysis (21 properties), OutcomeMeasure (17 properties), FieldNode (16 properties). Each schema is shown below with its type and property counts.

WhoMasked
string
FlowPeriod
object
3 properties
Retraction
object
2 properties
DocumentSection
object
1 property
GeoName
string
State/province or city name
InterventionalAssignment
string
DesignMasking
string
ExpandedAccessInfo
object
3 properties
OrgStudyIdType
string
MeasureAnalysis
object
21 properties
GeoPoint
object
2 properties 2 required
StudiesCsv
string
Study objects in csv file
DescriptionModule
object
2 properties
DesignTimePerspective
string
AnalysisDispersionType
string
errorMessage
string
A text message describing an error
StandardAge
string
NonInferiorityType
string
MoreInfoModule
object
3 properties
OutcomesModule
object
3 properties
FirstMcpInfo
object
1 property
BaselineMeasure
object
10 properties
CertainAgreement
object
4 properties
SearchPart
object
5 properties 5 required
MeasureCategory
object
2 properties
ExpandedAccessTypes
object
3 properties
FlowStats
object
4 properties
StudiesZip
string
Study objects as files in zip archive
FieldNodeList
array
LargeDocumentModule
object
2 properties
SponsorCollaboratorsModule
object
3 properties
ProtocolSection
object
13 properties
ResponsiblePartyType
string
SearchDocumentList
array
OrgStudyIdInfo
object
3 properties
Contact
object
5 properties
DesignInfo
object
7 properties
ArmsInterventionsModule
object
2 properties
ContactsLocationsModule
object
3 properties
ResponsibleParty
object
6 properties
StudyFhir
object
Study in FHIR JSON format
StatusModule
object
21 properties
PartialDateStruct
object
2 properties
SamplingMethod
string
EventGroup
object
9 properties
BioSpecRetention
string
PrimaryPurpose
string
AgencyClass
string
Status
string
MaskingBlock
object
3 properties
ParticipantFlowModule
object
5 properties
MeasureParam
string
UnpostedAnnotation
object
2 properties
SubmissionTracking
object
3 properties
Official
object
3 properties
EventAssessment
string
MeasureGroup
object
3 properties
DateTimeMinutes
string
Date and time in yyyy-MM-dd'T'HH:mm format
DesignAllocation
string
Measurement
object
6 properties
UnpostedEvent
object
3 properties
OutcomeMeasuresModule
object
1 property
PagedStudies
object
3 properties 1 required
FlowMilestone
object
3 properties
AvailIpd
object
4 properties
Intervention
object
5 properties
EnumInfoList
array
EventStats
object
4 properties
StudyType
string
BrowseLeaf
object
4 properties
MiscInfoModule
object
3 properties
ConfidenceIntervalNumSides
string
UnpostedEventType
string
ContactRole
string
EnrollmentType
string
ReferencesModule
object
3 properties
IpdSharingStatementModule
object
6 properties
AdverseEventsModule
object
7 properties
EnumItem
object
3 properties 2 required
DerivedSection
object
3 properties
ObservationalModel
string
SearchDocument
object
2 properties 2 required
BrowseModule
object
4 properties
Mesh
object
2 properties
PartialDate
string
Date in yyyy, yyyy-MM, or yyyy-MM-dd format
BioSpec
object
2 properties
StudyList
array
study field values of type markup are in markdown format.
ReportingStatus
string
SeeAlsoLink
object
2 properties
AdverseEvent
object
6 properties
BaselineCharacteristicsModule
object
5 properties
SecondaryIdInfo
object
4 properties
LargeDoc
object
9 properties
PointOfContact
object
5 properties
EligibilityModule
object
10 properties
ExpandedAccessStatus
string
DateStruct
object
2 properties
AnnotationModule
object
2 properties
DropWithdraw
object
3 properties
DateType
string
FieldNode
object
16 properties 4 required
Outcome
object
3 properties
RecruitmentStatus
string
Sponsor
object
2 properties
ViolationEventType
string
ResultsSection
object
5 properties
LimitationsAndCaveats
object
1 property
IpdSharing
string
BrowseLeafRelevance
string
MeasureDispersionType
string
OfficialRole
string
MeasureClass
object
3 properties
ReferenceType
string
BrowseBranch
object
2 properties
OutcomeMeasureType
string
IdentificationModule
object
8 properties
Organization
object
2 properties
EnrollmentInfo
object
2 properties
Sex
string
ConditionsModule
object
2 properties
ArmGroup
object
4 properties
Phase
string
SubmissionInfo
object
5 properties
OversightModule
object
7 properties
Study
object
6 properties
Location
object
8 properties
SecondaryIdType
string
DesignModule
object
9 properties
nct
string
NCT number
DenomCount
object
2 properties
OutcomeMeasure
object
17 properties
ArmGroupType
string
SearchArea
object
4 properties 2 required
WebLink
object
2 properties 2 required
AnnotationSection
object
1 property
ViolationAnnotation
object
1 property
ViolationEvent
object
6 properties
AgreementRestrictionType
string
Reference
object
4 properties
FlowGroup
object
3 properties
Denom
object
2 properties
InterventionType
string
IpdSharingInfoType
string
EnumInfo
object
3 properties 3 required

Specification

The full machine-readable OpenAPI contract behind this narrative.

Source

nih-studies-api-openapi.yml Raw ↑

Other APIs National Institutes of Health (NIH) publishes across the network.

NCBI E-utilities (Entrez Programming Utilities)
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PubChem Power User Gateway (PUG REST)
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NIH RePORTER API
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NCBI BLAST URL API
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PubMed Central (PMC) OA API
AE Profile APIs.io
National Institutes of Health (NIH) BioSample API
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National Institutes of Health (NIH) Gene API
AE Profile APIs.io
National Institutes of Health (NIH) Genome API
AE Profile APIs.io
National Institutes of Health (NIH) Organelle API
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National Institutes of Health (NIH) Prokaryote API
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National Institutes of Health (NIH) Stats API
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National Institutes of Health (NIH) Taxonomy API
AE Profile APIs.io
#Studies
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API Details
ID
nih:nih-studies-api
Base URL
https://eutils.ncbi.nlm.nih.gov/entrez/eutils/
Docs
https://www.ncbi.nlm.nih.gov/home/develop/api/
Provider
National Institutes of Health (NIH)
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