It is a clinical trial where specific information – such as group allocation (e.g. treatment versus placebo) – is withheld from participants, researchers, or evaluators to prevent bias.
- National Cancer Institute (NCI) https://www.cancer.gov/publications/dictionaries/cancer-terms/def/blinded-study
To go in depth
Blinding purpose is to prevent subjective reporting of side effects or benefits. It also improves data quality, ensuring that the results are due to the treatment, not participant or researcher expectations. Finally, it overcomes the placebo effect.
There are different types of blinding:
- Single blind: only the participants do not know which treatment they are receiving.
- Double blind: neither the participants nor the research team/doctors know who is receiving the treatment or the placebo.
- Triple blind: participants, researchers, and data analysts are unaware of the treatment assignments.
- EUPATI Open Class https://learning.eupati.eu/mod/book/tool/print/index.php?id=342#:~:text=For%20example%2C%20if%20we%20want,to%20which%20treatment%20is%20which
