Office of Clinical Research

ClinicalTrials.Gov Definitions Definitions

    A public registry developed by the National Library of Medicine (NLM) as part of a mandate from the Food and Drug Administration Modernization Act (FDAMA) and further enhanced to include a results database as part of a mandate from FDAAA.
  • Enrollment
    Typically defined as placing a consenting a human research subject into a clinical trial.
  • Food and Drug Administration (FDA), Food and Drug Administration Amendments Act (FDAAA) Applicable Clinical Trial (ACT)

    a. Drug/Biologic – a controlled, clinical investigation, other than a phase I clinical investigation, of a drug subject to section 505 of the Federal Food, Drug, and Cosmetic Act or to section 351 of the Public Health Service Act, where ‘clinical investigation’ has the meaning given in 21 CFR 312.3 (or any successor regulation) and ‘Phase I’ has the meaning given in 21 CFR 312.21 (or any successor regulation).

    b. Device – a prospective clinical study of health outcomes comparing an intervention with a device subject to section 510(k), 515, or 520(m) of the Federal Food, Drug, and Cosmetic Act against a control in human subjects (other than a small clinical trial to determine the feasibility of a device, or a clinical trial to test prototype devices where the primary outcome measure relates to feasibility and not to health outcomes); and a pediatric post-market surveillance of a device as required under section 522 of the Federal Food, Drug, and Cosmetic Act.

  • International Committee of Medical Journal Editors (ICMJE) clinical trial
    Any research project that prospectively assigns people or a group of people to an intervention, with or without concurrent comparison or control groups, to study the cause-and-effect relationship between a health-related intervention and a health outcome.
  • National Clinical Trial Number
    An eight-digit number initiated with the acronym NCT that is assigned to identify the record and is issued when the record registration is publically posted on
  • National Institutes of Health (NIH) clinical trial
    A research study in which one or more human subjects are prospectively assigned to one or more interventions (which may include placebo or other control) to evaluate the effects of those interventions on health-related biomedical or behavioral outcomes.
  • Primary Completion Date
    The date that the final subject was examined or received an intervention for the purposes of final collection of data for the primary outcome measure.
  • Principal Investigator
    The responsible leader of a team of investigators (and research team) who has the ultimate responsibility for the conduct of the research. The Principal Investigator is delegated the Responsible Party role and assumes the associated responsibilities on an Indiana University or investigator initiated clinical trial.
  • Protocol Registration and Results System (PRS)
    The internal system where data entry is completed prior to the public posting of the record on Each sponsoring entity has an assigned PRS organizational account.
  • Responsible Party
    The entity or individual who is responsible for registering a clinical trial and submitting clinical trial data to