FAQ: Why is cohort a visit-level field, and how to map participant-level cohort from REDCap?

While a participant's cohort rarely changes mid-study, it can happen. For example, a participant may be DM+ and IBD+ at Visit 1 but DM+ and IBD– at Visit 2. To accurately capture such changes, the cohort field is placed at the visit level in OpenSpecimen.

If the cohort rarely changes in a study, users can create a custom field at the participant level and map it to the REDCap cohort field.