Safety and research
RCT
Definition
A randomized controlled trial assigns participants by chance to intervention groups and compares outcomes between the concurrently followed groups.
Aliases and abbreviations
RCT · randomised controlled trial · randomized trial
Editorial record
Published: August 25, 2026 · Reviewed: August 25, 2026
Expanded definition
Random allocation aims to make prognostic factors similar on average between groups before the intervention begins, reducing confounding in the estimated comparison.
A control group may receive sham stimulation, another intervention, standard care, or no intervention. Blinding, allocation concealment, adherence, missing data, outcome measurement, and selective reporting still affect validity.
An RCT estimates an effect for the tested population, protocol, comparator, and outcomes. Its result should not automatically be transferred to another device, dose, setting, or intended use.
What the term does not establish
Why the distinction matters
Understanding what randomization does—and does not do—helps readers interpret trial results without treating the design label as a quality guarantee.
Main guide
Browse individual trials and evidence summaries across VNS methods and research questions.
Browse studiesRelated terms
Safety and research
Measurement and interpretation
Safety and research
Safety and research
Measurement and interpretation
Safety and research
Editorial scope
This glossary entry supports general education. It does not diagnose, recommend treatment, or transfer findings from one VNS method, protocol, or device to another.