The National Institutes of Health’s Office of Science Policy has released a revised definition of the term “clinical trial.” According to the OSP, this change was made in order to:

…make the distinction between clinical trials and clinical research studies clearer and to enhance the precision of the information NIH collects, tracks, and reports on clinical trials. The change is not intended to expand the scope of the category of clinical trials. No changes have been made to the NIH definition of a “Phase III clinical trial.”

The revised definition, which is available in full here, along with detailed footnotes, now defines “clinical trial” as:

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.