Blinding (known as masking) is a method used to reduce bias by withholding specific information from study participants, investigators, or both. This lack of knowledge prevents preconceived notions or expectations that could influence research outcomes.

Blinding can be single (participants or investigators) or double (both), and it enhances the validity of clinical trial results by minimizing unconscious biases and ensuring a more objective evaluation of interventions.

Definitions

ICH E6

A procedure in which one or more parties to the trial are kept unaware of the treatment assignment(s). Single-blinding usually refers to the subject(s) being unaware, and doubleblinding usually refers to the subject(s), investigator(s), monitor, and, in some cases, data analyst(s) being unaware of the treatment assignment(s).

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