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NIH Definition of Clinical Trial Case Studies

The case studies provided below are designed to help you identify whether your study would be considered by NIH to be a clinical trial. Expect the case studies and related guidance to evolve over the upcoming year. For continuity and ease of reference, case studies will retain their original numbering and will not be renumbered if cases are revised or removed.

The simplified case studies apply the following four questions to determine whether NIH would consider the research study to be a clinical trial:

  • Does the study involve human participants?
  • Are the participants prospectively assigned to an intervention?
  • Is the study designed to evaluate the effect of the intervention on the participants?
  • Is the effect being evaluated a health-related biomedical or behavioral outcome?

If the answer to all four questions is “yes,” then the clinical study would be considered a clinical trial according to the NIH definition.


See this page for more information about the NIH definition of a clinical trial.


On this page:

General Case Studies

Updated: 4/28/2021
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Institute or Center specific Case Studies

New: 1/4/18
This page last updated on April 28, 2021
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