In the Clinical Trials dataset you will find details specific to clinical trials, such as intervention model, arms, start date, and eligibility, as well as some linked literature and grants data. Below is a glossary of terms that can be found in the Clinical Trials dataset (search fields, record view, export, and more) along with example search criteria.
To learn more about how to search using search fields, visit the Search Strategies section. Note: When performing a manual query, search fields can be selected by clicking the Search Fields button below the Search icon in the search bar. If a field is not displayed in the list, you can still search it by using a Custom Field.
Acronym: This field contains the commonly used acronym or abbreviation for each clinical study.
Example:ISS-RESMEPO
AI labels: These are the AI labels for clusters across the different display levels (broad, intermediate, and narrow). You can use this field to search for terms or phrases in the labels. Read more about AI labels.
Example:Antibodies
Allocation: This is the method used to assign participants to an arm of a clinical study. The types of allocation are randomized and nonrandomized. Potential values are: Randomized, Non-Randomized, and blank.
Example:Randomized
All People Affiliations: Field contains the organization(s) affiliated with the people listed on the Clinical Trial.
Example:"Duke University"
All People Degrees: Field contains the degree levels achieved by the people listed on the Clinical Trial.
Example:MD
All People First Names: Field contains the first names of the people listed on the Clinical Trial.
Example:Karen
All People Last Names: Field contains the last names of the people listed on the Clinical Trial.
Example:Waldman
All People Names: Field contains the names of the people listed on the Clinical Trial.
Example:Amati, Francesca;Tappy, Luc
All People Investigator Roles: Field shows which people listed on the Clinical Trial are Principal Investigators.
Example:"Principal Investigator"
All People Types: This field contains the recorded roles for each person listed on the Clinical Trial.
Example:lead
Arm Group Description: An “arm” means a pre-specified group or subgroup of participant(s) in a clinical trial assigned to receive specific intervention(s) (or no intervention) according to a protocol. This field describes the individual clinical trial arms.
Example:(receive AND doses AND ataluren)
Arm Group Label: This field provides the label for each arm group within the clinical trial.
Example:Perampanel
Arm Group Type: This field describes the clinical trial arm type. It identifies the role of the intervention that participants receive. Types of arms include experimental arm, active comparator arm, placebo comparator arm, sham comparator arm, and no intervention arm.
Example:"placebo comparator"
Biospec Retention: Biospecimen Retention. This field indicates whether samples of material from research participants are retained in a biorepository. Potential values are: None Retained, samples With DNA, or Samples Without DNA.
Example:“samples With DNA”
Biospec Description: Biospecimen Description. This field lists all types of biospecimens to be retained (e.g., whole blood, serum, white cells, urine, tissue).
Example:“white cells”
Brief Summary: This is a short description of the clinical study, including a brief statement of the clinical study's hypothesis. You can search for terms or phrases in the brief summary of a clinical study without needing to include the full, exact summary.
Example:“breast cancer”
Brief Title: This is the abbreviated title of the clinical trial. If using this as a search field, you can find terms or phrases in the title without needing to include the entire, exact title.
Example:Migraine
Collaborator Agency: This contains the name of an organization, other than the Sponsor, that provides support for a clinical study. This support may include funding, design, implementation, data analysis, or reporting. Note: In the Record view, this field is listed in a table under Sponsor Name.
Example:“National Institute of Allergy and Infectious Disease”
Collaborator Agency Class: This contains the class of the organization listed as a collaborator agency on the clinical trial.
Examples:Industry
Chemicals and Drugs: These are chemical and drug names extracted from pieces of literature using a custom dictionary. The chemicals/drugs dictionary is derived from the MeSH tree.
Example:Estrogen
Completion Date: This is the date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). This can be Anticipated or Actual (see Completion Date Type field).
Example:September 22, 2026
Completion Date Type: This is the type of completion date shown in the Completion Date field. Possible values are Anticipated or Actual.
Example:Anticipated
Condition: This is the name(s) of the disease(s) or condition(s) studied in the clinical study, or the focus of the clinical study.
Example:Nephrosis
Contacts Affiliation: This is the organization affiliated with the enrollment contact(s).
Example:“Virginia Commonwealth University"
Contacts Degrees: Field contains the degree levels achieved by the contacts listed on the Clinical Trial.
Example:MD
Contacts Name: This is name of a person to whom questions concerning enrollment at any location of the study can be addressed.
Example:“Liu, Wei”
Contacts First Name: This is first name of a person to whom questions concerning enrollment at any location of the study can be addressed.
Example:“Wei”
Contacts Last Name: This is last name of a person to whom questions concerning enrollment at any location of the study can be addressed.
Example:“Liu”
Contacts Types: This field contains the recorded role types for each contact person listed on the Clinical Trial. Values include 'facility contact' and 'overall contact'.
Example:"overall contact"
CT URL: This is the link for the clinical trial of interest at the clinicaltrials.gov webpage.
Example:https://classic.clinicaltrials.gov/ct2/show/NCT05910476
Detailed Description: This is an extended description of the clinical study protocol. You can search for terms or phrases in the description of a clinical study without needing to include the full, exact description.
Example:“diabetes type 2”
Devices: This an extracted field based on content in the Brief Title, Official Title, and Intervention fields. These fields are searched for terms from a dictionary of devices. The definition of a device is any healthcare product that does not achieve its principal intended purposes by chemical action or by being metabolized. Multiple values are separated by ';'.
Example:“injection device”
Early Phase: This field indicates whether the clinical trial is an early phase trial. Early Phase includes 'Early Phase 1', 'Phase 1', and 'Phase 1/Phase 2'. Values are Yes or No.
Eligibility Criteria: This field contains the criteria that set out eligibility for inclusion in the clinical trial.
Example:youth
Enrollment Count: This is the number of participants within a clinical study. This number can be the actual number or an anticipated number. Use in conjunction with the Enrollment Type field.
Example:1,000
Enrollment Type: There are two enrollment type values: Actual and Anticipated. Actual is the number of study participants actually enrolled in a study and Anticipated is the number of study participants that are expected to enroll.
Example:Actual
Facility City: This is the city/cities of the facilities participating in clinical studies.
Example:Cairo
Facility Country: This is the country/countries of the facilities participating in clinical studies.
Example:Egypt
Facility Investigator Name: This is the name(s) of the investigator(s) from the facilities participating in clinical studies. Multiple investigators are separated by ';'.
Example:“Bisschop, Peter H”
Facility Investigator Role: This is the role(s) of the facility investigator in the clinical study. Possible values are Principal Investigator or Sub-Investigator.
Example:“Principal Investigator”
Facility Name: This is the full names(s) of the organization(s) where the clinical study is being conducted.
Example:“Saga University Hospital”
Facility State: This is the state(s) of the facilities participating in clinical studies.
Example:Pennsylvania
Facility Zip: This is the zip code(s) of the facilities participating in clinical studies.
Example:19104
FDA Regulated Drug: This field says whether the clinical trial studies a U.S. FDA-regulated drug product. Possible values are Yes, No, or blank.
Example:Yes
FDA Regulated Device: This field says whether the clinical trial studies a U.S. FDA-regulated device product. Possible values are Yes, No, or blank.
Example:Yes
First Received Date: This is the date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on clinicaltrials.gov (the first posted date). This field is called 'First Submitted date' in ClinicalTrials.gov
Example:2023-03-31
First Received Year: The is the year in which summary clinical study information was first available on clinicaltrials.gov. First Received Year is the calendar year of the First Received Date.
Example:2023
First Results Received Date: The date on which the study sponsor or investigator first submits a study record with summary results information. There is typically a delay between the results first submitted date and when summary results information becomes available on ClinicalTrials.gov (the results first posted date).
Example:2022-10-01
Has Raw PMIDs: This field indicates if a clinical trial has PMIDs (not limited to results) associated with it.
Example:Yes
Has Raw Results PMIDs: This field indicates if a clinical trial has results PMIDs associated with it.
Example:Yes
Has Results: This field indicates if the clinical trial has results, either linked PMIDs (publications) containing results or date first results received to identify if a clinical trial has results.
Example:Yes
Intervention: With this field you can search for a process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as surveys, education, and interviews.
Example:Capsaicin
Intervention Model: This is the general design of the strategy for assigning interventions to participants in a clinical study. Types of intervention models include: Single Group Assignment, Parallel Assignment, Crossover Assignment, Sequential Assignment, and Factorial Assignment. Field can also be blank.
Example:“Parallel Assignment”
Intervention Model Description: This field describes the intervention model in detail. Free text field.
Example:“single dose”
Intervention Name: This is a normalized intervention field created based on text extracted from the official title, brief title, and intervention fields from clinicaltrials.gov.
Example:Nivolumab
Intervention Other Names: This field contains other current and former name(s) or alias(es), if any, different from the Intervention Name(s) that the sponsor has used publicly to identify the intervention(s), including, but not limited to, past or present names such as brand name(s), or serial numbers.
Example:Advil
Intervention type: This is a process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Example:device
Investigator Affiliations: Field contains the organization(s) affiliated with the Investigators listed on the Clinical Trial.
Example:"Cedars-Sinai Medical Center"
Investigator Degrees: Field contains the degree levels achieved by the Investigators listed on the Clinical Trial.
Example:MD
Investigator Names: Field contains the names of the Investigators listed on the Clinical Trial.
Example:"Anger, Jennifer"
Investigator Roles: Field shows the roles of the Investigators listed on the Clinical Trial. Examples include 'Study Chair', 'Study Director', 'Sub-investigator'
Example:"study chair"
Investigator Type: This field contains the recorded roles for each Investigator listed on the Clinical Trial. Types include 'official', 'facility contact', 'overall contact', 'facility investigator'. An individual can have more than one type on the same trial.
Example:official
Keywords: These are words or phrases that best describe the clinical trial protocol.
Example:“Kidney Disease”
Last Changed Date: This is the date on which the last update was submitted to ClinicalTrials.gov. Note that this date will be a few days before the Last Update Posted date on clinicaltrials.gov.
Example:2019-12-13
Lead Sponsor Agency: This is the lead sponsor agency where the sponsor is the organization or person who oversees the clinical study and is responsible for analyzing the study data. Note: In the Record view, this field is listed in a table under Sponsor Name.
Example:”National Institute of Diabetes and Digestive and Kidney Diseases”
Lead Sponsor Agency Class: This field describes the type of lead sponsor agency for a clinical study. Clinicaltrials.gov refers to four types of funders: U.S. National Institutes of Health, Other U.S. federal agency (e.g., FDA), Industry (e.g., pharmaceuticals), and Other (e.g., universities or community-based organizations). This field can be seen in the record view or in export. Note: In the record view, this field is listed in a table under Sponsor Name.
Example:Industry
Linked Data: This field shows which other datasets the record is linked to, Grants or Literature. Multiple values are separated by ';'.
Example:Literature
Linked Grants Activity Code: This field indicates the type of grant record that supported the clinical trial. Activity codes are composed of 3-characters used to identify a specific category of extramural research activity (see the Grants glossary for more information).
Example:R01
Linked Grants Admin IC: This is the full IC acronym, usually 2-5 letters, to designate the agency, NIH Institute, or Center that supported the clinical trial. See Institute/Center code definitions.
Example:NIGMS
Linked Grants Appl ID: This field can be used to search the grant record application identification number associated with a grant record that is linked to the clinical trial.
Example:6825594
Linked Grants Count (Count of Linked Grants): The total number of grants linked to the clinical trial.
Example:6
Linked Grants Fiscal Year: This is the Fiscal Year(s) (FY) of grants linked to clinical trials. A FY begins on October 1 and ends September 30 of the following year, e.g., FY2018: Started October 1, 2017 and ended September 30, 2018.
Example:2022
Linked Grants Funding Agency: This is the funding agency of grants linked to clinical trials.
Example:“National Institutes of Health (NIH)”
Linked Grants Grant Number: This is the grant number linked to the clinical trial.
Example:R01DK043752
Linked Grants PI IDs: Field contains the PI Identifiers (PIIDs) of the Grant Principal Investigators for grants linked to the clinical trial.
Example:"8484271;1944911"
Linked Grants PI Names: Field contains the names of the Grant Principal Investigators for grants linked to the clinical trial.
Example:"Medina, Kay Lynn"
Linked Grant Source: Field containing a hyperlink to the RePORTER record for the linked grant. Note this field is not searchable.
Linked Publication Authors: This field lists the authors on each publication linked to the clinical trial.
Example:"Glassock, Richard"
Linked Publication Citation Count: This field contains the number of citations for each publication linked to the clinical trial.
Example:187;787
Linked Publication Link Type: This field identifies the type of publication to clinical trial linkage. Values include 'Cited' (Cited by the Clinical Trial) or 'Published' (results of the clinical trial).
Example:cited
Linked Publication PMID: This is the unique number assigned to a PubMed citation for an article published in a journal. Search PMIDs that are cited by clinical trials or literature that results from a clinical trial.
Example:15161733
Linked Publication RCR: Relative Citation Ratio (RCR) of publication(s) cited by the clinical trial. Field will contain multiple values if the trial cites multiple publications (and RCR is available).
Example:2.2;0.5
Linked Publication Source: Field containing a hyperlink to the PubMed record or preprint server for the linked literature. Note this field is not searchable.
Example:Pubmed
Linked Publication Title: Field contains the title of each publication linked to the clinical trial. You can search for keywords in the title also.
Example:"breast cancer"
Linked Publication Year: This is the publication year of articles cited by the clinical trial. Field will contain multiple values if the trial cites multiple publications.
Example:2020;2021
Location Country: These are the countries in which research facilities for a study are located.
Example:France;Italy;Canada
Masking: This is a clinical trial design strategy in which one or more parties involved in the trial, such as the investigator or participants, do not know which participants have been assigned which interventions. Types of masking include: open label, single-blind masking, and double-blind masking. Field values are None, Single, Double, Triple, Quadruple with detail in parentheses. Field can also be blank.
Example:“Double (Participant, Investigator)”
Masking Description: This provides information about how the masking will be carried out in the trial.
Example:“Participant, care provider, and investigator are not masked”
MeSH Plus: Medical Subject Headings (MESH) are assigned to Clinical Trials to identify content, in a similar way to RCDC for grants. MeSH Plus identifies extracted MeSH terms in relevant content fields (specifically: brief Title, official Title, brief Summary, condition and keywords). The dictionary used is a version of the MeSH tree with some terms and phrases removed to improve search results.
Example:Transplantation
NIH Linked: This field indicates whether the Clinical Trial is linked to an NIH grant, or NIH is the lead sponsor or collaborator Agency. Values are Yes or No.
Example:Yes
Number of Arms (Interventional): An “arm” means a pre-specified group or subgroup of participants in an Interventional clinical trial assigned to receive a specific intervention(s) (or no intervention) according to a protocol. For a trial with multiple periods or phases that have different numbers of arms, the number of arms is the maximum number of arms during all periods or phases.
Example:2
Number of Groups (Observational): In Observational studies, group is used in place of “arm”, describing pre-specified groups or subgroups of participants in a clinical trial. For a trial with multiple periods or phases that have different numbers of arms, the number of arms is the maximum number of arms during all periods or phases.
Example:2
Observational Model: This is the general design of the strategy for identifying and following up with participants during an observational study. Types of observational study models include cohort, case-control, case-only, case-cross-over, ecologic or community studies, family-based, and other. Field can also be blank.
Example:“Defined Population”
Official Title: This is the full title of the clinical trial. If using this as a search field, you can find terms or phrases in the title without having to include the entire, exact title.
Example:“breast cancer”
Other Outcome Description: This defines how any other outcomes will be assessed. If using this as a search field, you can find terms or phrases in the outcome description.
Example:“cortisol levels”
Other Outcome Measure: Some clinical study protocols, will include outcomes in addition to the primary and secondary outcome measures. Additional outcome measures are listed in this field. If using this as a search field, you can find terms or phrases in the outcome measure.
Example:"change in sleep"
Other Outcome Time Frame: This defines the timeframe for measurement of any other outcome measures.
Example:“12 months”
Overall Status: This indicates the current stage of a clinical study and whether it is, or will be, open for enrollment.
Example:Recruiting
Phase: This is the stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions. Some phases can also be combined, e.g., Phase 1/Phase 2. Learn more about clinical trial phases.
Example:Phase 4
Primary Completion Date: This is the date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. The "estimated" primary completion date is the date that the researchers think will be the primary completion date for the study.
Example:2024-01-10
Primary Completion Date Type: Field identifies whether the Primary completion data is 'anticipated' or 'actual'. If there is no Primary Completion Date, the field is blank/empty.
Example:actual
Primary Outcome Description: This defines how the primary outcome will be assessed. If using this as a search field, you can find terms or phrases in the outcome description.
Example:“cortisol levels”
Primary Outcome Measure: In a clinical study's protocol, the primary outcome measure is the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one. If using this as a search field, you can find terms or phrases in the outcome measure.
Example:“Noninferiority in mean differences between groups in their daily blood glucose concentrations”
Primary Outcome Time Frame: This defines the timeframe for measurement of the primary outcome measure.
Example:“12 months”
Primary Purpose: This is the main reason for the clinical trial. Possible primary purposes include: Treatment, Prevention, Diagnostic, Supportive Care, Screening, Health Services Research, Basic Science, Device Feasibility, Educational/Counseling/Training, and Other. This field can also be blank.
Example:Prevention
Principal Investigator Affiliation: This is the organization affiliated with the Principal Investigator for the clinical trial.
Example:“National University of Malaysia”
Principal Investigator (PI) Name: This the name of the principal investigator (PI)/person who is responsible for the scientific and technical direction of the entire clinical study. Format is first name space last name. Multiple PIs are separated by ';'.
Example:“Norfilza Mokhtar”
Principal Investigator Degree: Field contains the degree levels achieved by the Principal Investigator for the Clinical Trial.
Example:MD
Results First Posted Date: The date on which summary results information was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay between the date the study sponsor or investigator first submits summary results information (the results first submitted date) and the results first posted date.
Example:2010-01-20
Results First Posted Date Type: This field shows whether the Results First Posted Date is 'Estimated' or 'Actual'.
Example:Estimated
Start Date/From: This is the date when the first participant was enrolled in a clinical study. This can be Anticipated or Actual (see Start Date Type field).
Example:2010-01-20
Start Date Type: This field contains the type of completion date shown in the Start Date field. Possible values are Anticipated or Actual.
Example:Actual
Start Year: The year in which the first participant was enrolled in the clinical study. Taken from the Start Date field.
Example:2010
Secondary Outcome Description: This defines how the primary outcome will be assessed. If using this as a search field, you can find terms or phrases in the outcome description.
Example:“cortisol levels”
Secondary Outcome Measure: In a clinical study's protocol, the secondary outcome measure is a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Example:“Lipid Profile (triglyceride level , LDL ,HDL ,Total cholesterol)”
Secondary Outcome Time Frame: This defines the timeframe for measurement of the secondary outcome measure(s).
Example:“2 weeks”
Source: The source of the clinical trial record. Currently all clinical trial data comes from clinicaltrials.gov.
Sponsor Class: Sponsor Class is used in the Sponsor Collaborator table in the Record View. The table shows the Lead Sponsor Agency Name and/or the Collaborator Agency Name. The Sponsor Class field describes the organization that provides funding or support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting. There are four types of sponsors: U.S. National Institutes of Health, Other U.S. federal agency (e.g., FDA), Industry (e.g., pharmaceuticals), and Other (e.g., universities or community-based organizations). This is also a Refine Panel filter. Note: The refine filter is a combination of the lead sponsor and collaborator fields.
Example:"Industry"
Sponsor Name: This is used in the Sponsor Collaborator table in the Record View. The table shows the Lead Sponsor Agency Name and/or the Collaborator Agency Name.
Example:"Roche Holding AG"
Sponsor Type: This is used in the Sponsor Collaborator table in the Record View to differentiate between sponsor agency and collaborator agency.
Example:"Lead"
Study model: This describes the type of Interventional Model or Observational Model being used in the study. This is available as a filter under the Refine Panel and can be seen in the Results View. To understand which type of model it is, see the Study Type field in the Record View. You can also download the specific model by selecting the Interventional Model and/or Observational Model fields from the export window.
Example:"Parallel Assignment"
Study Type: This is the nature of the investigation or investigational use for which clinical study information is being submitted. Field will contain: Interventional (clinical trial), Observational, Patient Registry, or Expanded Access.
Example:"Interventional"
System ID: For the clinical trials dataset, this field is the clinical trial number. A unique identification code is given to each clinical study registered on clinicaltrials.gov. Clinical trial numbers, otherwise known as NCT numbers, begin with "NCT" followed by an 8-digit number.
Example:NCT00255398
Target: These are drug targets and are created using a dictionary of target terms and searching the text of the Title and Abstract in articles. The dictionary comes from http://www.guidetopharmacology.org/.
Example:SLC12A9
Total Publications: This is the number of literature (publications) cited by the clinical trial.
Example:10
Trial Eligibility - Eligibility Criteria: The key standards that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility Criteria include both inclusion criteria and exclusion criteria. For most records Inclusion and Exclusion criteria are split into the 'Exclusion Criteria' and 'Inclusion Criteria' fields, so for many records this field will be blank.
Example:pregnan*
Trial Eligibility - Exclusion Criteria: Eligibility Criteria are the key standards that people who want to participate in a clinical study must meet or the characteristics they must have. Exclusion criteria are the characteristics someone may have which would prevent them from participating.
Example:immunocompromised
Trial Eligibility - Gender: This field allows you to search by the gender of the participants eligible to participate in a clinical study.
Example:Female
Trial Eligibility - Inclusion Criteria: Eligibility Criteria are the key standards that people who want to participate in a clinical study must meet or the characteristics they must have. Inclusion criteria are the characteristics someone must have in order to participate.
Example:smok*
Trial Eligibility - Maximum Age: This is the maximum age a person can be to participate in a specific clinical study.
Example:“18 years”
Trial Eligibility - Minimum Age: This indicates the minimum age a person must be to participate in a specific clinical study.
Example:“10 years”
Unapproved Device: This is a flag to indicate devices or product not approved or cleared by U.S. FDA. Values are Yes, No, and blank.
Example:No
US Export: This is a flag to indicate products manufactured in and exported from the U.S. Values are Yes, No, and blank.
Example:Yes
Verification Date: This is the most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current.
Example:2008-09-05