# About multi-instance forms and visits

Your study may include any number of multi-instance forms or items, including:

- Repeating forms.
- Non-repeating forms that occur within repeating visits.
- Itemsets.

When you create ad hoc reports, you can include data from more than one of these multi-instance forms, items, or visits on the same report.

A report can accurately provide data on the adverse events and concomitant medications for a subject. For example, it can accurately illustrate the relationships between:

- The subject and each adverse event.
- The subject and each medication.
- The adverse event and its associated concomitant medication.

Note: When the same form is used in multiple visits, if a subject does not have any instances of the form, the resulting report may display extra rows that contain incomplete information.

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