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Compound Evidence InstituteEvidence synthesis · established 2023Graded assessments of compounds, trials, methods and supply
Document set current to 30 July 2026
Defined term · Trial design and conduct

Run-in period

A period before randomisation during which all participants receive the same treatment. A run-in that excludes non-responders or non-tolerators produces a randomised population that is not the…

Document identifier
CEI-GT-047
Series
Defined term
Version
1.0
Published
30 Jul 2026
Last reviewed
30 Jul 2026
Certainty
Not rated

§1Run-in period

§1.1Also known as

Lead-in

§1.2Category

Trial design and conduct — Terms describing how a clinical study is constructed and run.

§1.3Related terms

  • Randomised withdrawal — A design in which participants who have responded during an open-label lead-in are randomised to continue or to discontinue. Establishes whether an effect requires…
Compound Evidence Institute · CEI-GT-047 · https://compoundevidence.com/glossary/run-in-period/ · retrieved 30 July 2026
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