Clinical Research Glossary

substudy substudy


A study with a smaller group of participants already enrolled in the main study.

Example of substudy in a sentence

A substudy is a study to answer questions related to the main study.

More Info

A substudy asks a separate research question from the main study. It adds to the main study’s objectives and uses all or a subset of participants or samples from the main study.

A substudy is sometimes designed at the beginning of the main study. It is also possible that a substudy could happen later after some data have been analyzed.

Other info to think about when joining a study

When you enroll in a study, there may be additional substudies you can choose to enroll in. For some substudies, you may need to go in for extra study visits or do some extra tests. The study team may want to collect more information from you to answer additional questions that the first study you enrolled in is not looking at. You will be consented for additional substudies.

You may want to ask if there are substudies in the study you join. Additionally, you can ask if you have to join any substudies and ask for more information about how the substudy is different from the first study you are enrolling in. It could also be helpful to ask if you have to do additional tests or go in for more study visits if you join a substudy. This could help you decide if you have the time to join.

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