Research & Regulation
Randomized Controlled Trial (RCT)
Also called: RCT, randomized trial
Definition
A study in which participants are assigned by a random process to different intervention or control groups.
What Randomized Controlled Trial (RCT) means
Randomization helps reduce systematic differences between comparison groups. Depending on the question, an RCT may compare a treatment with placebo, usual care, or another active treatment.
Why the distinction matters
The strength of an RCT still depends on factors such as sample size, blinding, outcome selection, missing data, duration, and whether the study population matches the question being asked.
Common confusion
Being randomized is an important design feature, but it does not automatically make every trial large, definitive, or free from bias.
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Related glossary terms
Research & Regulation
Placebo
A control intervention designed to resemble the study treatment without containing the active study intervention being evaluated.
Research & Regulation
Phase 2 Clinical Trial
A stage of human clinical development that commonly explores efficacy signals, dose selection, and continued safety assessment.
Research & Regulation
Phase 3 Clinical Trial
A later-stage clinical trial designed to provide substantial evidence about efficacy and safety in the intended population and use context.
Published September 6, 2026. BACToBasics glossary pages are educational definitions only and do not provide medical, dosing, preparation, treatment, or product-selection advice.