ClinicalTrials.gov Protocol Registration Data Element Definitions
for Interventional and Observational Studies

October 1, 2020

• Unique Protocol Identification Number *
  Definition: Any unique identifier assigned to the protocol by the sponsor.
  Limit: 30 characters.
  

  Brief Title *
  Definition: A short title of the clinical study written in language intended for the lay public. The title should include, where possible, information on the participants, condition being evaluated, and intervention(s) studied.
  Limit: 300 characters.

  Acronym [*]
  Definition: An acronym or abbreviation used publicly to identify the clinical study, if any.
  Limit: 14 characters.

  Official Title *§
  Definition: The title of the clinical study, corresponding to the title of the protocol.
  Limit: 600 characters.

  Secondary IDs [*]
  Definition: An identifier(s) (ID), if any, other than the organization's Unique Protocol Identification Number or the NCT number that is assigned to the clinical study. This includes any unique clinical study identifiers assigned by other publicly available clinical trial registries. If the clinical study is funded in whole or in part by a U.S. Federal Government agency, the complete grant or contract number must be submitted as a Secondary ID.
  Limit: 30 characters.

  If there is a Secondary ID, then the following information must be provided:

  Secondary ID Type [*]
  Definition: A description of the type of Secondary ID. Select one.
  
  

  • U.S. National Institutes of Health (NIH) Grant/Contract Award Number: In the Secondary ID field, include activity code, institute code, and 6-digit serial number. Other components of the full award number (type code, support year, and suffix) are optional.
  • Other Grant/Funding Number: Identifier assigned by a funding organization other than the U.S. NIH; also required to enter the name of the funding organization.
  • Registry Identifier: Number assigned by a clinical trial registry (for example, a registry that is part of the World Health Organization [WHO] Registry Network); also required to enter the name of the clinical trial registry.
  • EudraCT Number: Identifier assigned by the European Medicines Agency Clinical Trials Database (EudraCT).
  • Other Identifier: Also required to enter a brief description of the identifier (for example, the name of organization that issued the identifier).

  Description [*]
  Definition: If a Secondary ID Type of "Other Grant/Funding Number," "Registry Identifier," or "Other Identifier" is selected, provide the name of the funding organization, clinical trial registry, or organization that issued the identifier.
  Limit: 119 characters.

  Study Type *
  Definition: The nature of the investigation or investigational use for which clinical study information is being submitted. Select one.

  • Interventional (clinical trial): Participants are assigned prospectively to an intervention or interventions according to a protocol to evaluate the effect of the intervention(s) on biomedical or other health related outcomes.
    
    
  • Observational: Studies in human beings in which biomedical and/or health outcomes are assessed in pre-defined groups of individuals. Participants in the study may receive diagnostic, therapeutic, or other interventions, but the investigator does not assign specific interventions to the study participants. This includes when participants receive interventions as part of routine medical care, and a researcher studies the effect of the intervention.
    
    
    • Patient Registry: An observational study that is also considered to be a Patient Registry. This type of study should only be registered once in the Protocol Registration and Results System (PRS), by the sponsor responsible for the primary data collection and analysis.
      
      Note: The Agency for Healthcare Research and Quality (AHRQ) defines a Patient Registry as including an organized system that uses observational methods to collect uniform data (clinical and other) prospectively for a population defined by a particular disorder/disease, condition (including susceptibility to a disorder), or exposure (including products, healthcare services, and/or procedures) and that serves a predetermined scientific, clinical, or policy purpose. Patient registries may be single purpose or on-going data collection programs that address one or more questions.
  • Expanded Access: An investigational drug product (including biological product) available through expanded access for patients who do not qualify for enrollment in a clinical trial. Expanded Access includes all expanded access types under section 561 of the Federal Food, Drug, and Cosmetic Act: (1) for individual patients, including emergency use; (2) for intermediate-size patient populations; and (3) under a treatment IND or treatment protocol. (For more information on data requirements for this Study Type, see Expanded Access Data Element Definitions).

• Record Verification Date *
  Definition: The date on which the responsible party last verified the clinical study information in the entire ClinicalTrials.gov record for the clinical study, even if no additional or updated information is being submitted.

  Overall Recruitment Status *
  Definition: The recruitment status for the clinical study as a whole, based upon the status of the individual sites. If at least one facility in a multi-site clinical study has an Individual Site Status of "Recruiting," then the Overall Recruitment Status for the study must be "Recruiting." Select one.

  • Not yet recruiting: Participants are not yet being recruited
  • Recruiting: Participants are currently being recruited, whether or not any participants have yet been enrolled
  • Enrolling by invitation: Participants are being (or will be) selected from a predetermined population
  • Active, not recruiting: Study is continuing, meaning participants are receiving an intervention or being examined, but new participants are not currently being recruited or enrolled
  • Completed: The study has concluded normally; participants are no longer receiving an intervention or being examined (that is, last participant’s last visit has occurred)
  • Suspended: Study halted prematurely but potentially will resume
  • Terminated: Study halted prematurely and will not resume; participants are no longer being examined or receiving intervention
  • Withdrawn: Study halted prematurely, prior to enrollment of first participant

  Why Study Stopped *§
  Limit: 250 characters.
  Definition: A brief explanation of the reason(s) why such clinical study was stopped (for a clinical study that is "Suspended," "Terminated," or "Withdrawn" prior to its planned completion as anticipated by the protocol).

  Study Start Date *§
  Definition: The estimated date on which the clinical study will be open for recruitment of participants, or the actual date on which the first participant was enrolled.

  Note: "Enrolled" means a participant's, or their legally authorized representative’s, agreement to participate in a clinical study following completion of the informed consent process. Potential participants who are screened for the purpose of determining eligibility for the study, but do not participate in the study, are not considered enrolled, unless otherwise specified by the protocol.

  Primary Completion Date *
  Definition: The date that the final participant was examined or received an intervention for the purposes of final collection of data for the primary outcome, whether the clinical study concluded according to the pre-specified protocol or was terminated. In the case of clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all of the primary outcomes.

  Once the clinical study has reached the primary completion date, the responsible party must update the Primary Completion Date to reflect the actual primary completion date.

  Study Completion Date *§
  Definition: The date the final participant was examined or received an intervention for purposes of final collection of data for the primary and secondary outcome measures and adverse events (for example, last participant’s last visit), whether the clinical study concluded according to the pre-specified protocol or was terminated.

  Once the clinical study has reached the study completion date, the responsible party must update the Study Completion Date to reflect the actual study completion date.