Study design
Blinding
Keeping participants, clinicians or assessors unaware of group assignment to reduce bias.
What it means
Definition
Blinding. Blinding helps prevent expectations from influencing symptoms, care, outcome assessment or analysis. Lack of blinding is particularly important for subjective outcomes such as pain or fatigue.
What it can tell you
It can show how close the evidence is to a real human health outcome.
What it cannot tell you
It cannot prove that a treatment works in people unless human outcome data are available.
Headline trap
Why this matters in headlines
A trial of a supplement may overestimate symptom benefit if participants know they are receiving the active product.