run-in period run-in period
A planned time before randomization at the start of a research study for additional screening and participant preparation.
Example of run-in period in a sentence
Some studies have a run-in period, which occurs after informed consent and before randomization or any study drug or treatment is given, for additional screening, wash-out of other medications, or preparation.
More Info
A run-in period in a study can be a time to:
– Conduct more screening activities
– Wean participants off medications that they are taking at home
– Stabilize participants before the study treatment
– Practice study activities to support participants in completing the study.
More screening may be done in the run-in period because the second round of screening could have some increased risks, involve a longer procedure, or cost more.
During the run-in period, a participant could learn they are not able to continue in the study.
A run-in period could last from a few weeks to a few months, depending on the study
Other info to think about when joining a study
You may see the term “run-in period” in materials that talk about the design of a research study. For example, on clinicaltrials.gov, under the sections titled “Design Details” and “Arms and Intervention” there may be information that says if there is a planned run-in period in the study.
If a study you are thinking about joining has a run-in period, you can ask the study team how long the run-in period will last and what will happen during the run-in period.
