File/Picture variables allow users to upload documents or images directly from both the eCRF (investigator interface) and the ePRO (patient interface).

These variables are commonly used to collect supporting documentation such as clinical photographs, wound images, radiology exports, PDFs, signed forms, laboratory reports, DICOM files, or any other study-related document.

When configuring the variable, study designers can define which file formats are accepted. More than 25 file types are supported, including common image formats (JPG, PNG, HEIC), PDF documents, Microsoft Office files, archives, and DICOM files. Each file is limited to 5MB. There is no limit to the number of files for a study or a patient.

In ePRO, participants can either select an existing file from their device or capture a new photo directly using their smartphone camera. During upload, a progress indicator is displayed to provide real-time feedback on the upload status.

Data storage and analysis

Unlike most variables, File and Picture variables do not store the uploaded file itself as the variable value.

Instead, the associated variable behaves as a Yes/No variable:

• Yes: a valid file has been successfully uploaded.
• NC: no file is attached to the variable.

The uploaded file is stored separately and linked to the patient record.

No statistical analysis is available for this type of variable.

Filtering and data review

Because the variable behaves as a standard Yes/No variable, it can be used as a filter.

Users can quickly identify records with or without uploaded files using the standard filters:

• Is known → patients with at least one uploaded file.
• Is unknown → patients without an uploaded file.

This is particularly useful for monitoring study completeness and identifying missing documentation.

Limitations

File and Picture variables are intended for data collection and review. 

As a result, they are not available for statistical analyses and can not be used in dynamic formula (calculated variables).