The Subject Database import loads or reloads subject data in two situations: an initial import into an empty database, which the Datacapt team does for you, and a re-import after a form update, when you need to change the form structure without losing existing data, or add a few new participants.
Imports write directly into live study data, which is why this article is mostly about care rather than clicks.
⚠️ Warning: before deleting questions, changing the Subject Database form, or running any import, contact your Customer Success Manager.
An import always carries a risk of data loss or inconsistency if the file and the form configuration are not aligned, and the damage is not always visible immediately. Your CSM can review your approach first. An initial import into an empty database must be done by the Datacapt team.
1. Finalize your form first
Make sure the Subject Database form is fully configured.
If you need to add questions, do it now.
Do not delete questions that already hold data unless your CSM has validated it.
Once the import starts, Datacapt relies entirely on the current form structure.
2. Export what you already have
Exporting first does two jobs: it gives you a backup, and it gives you the exact file structure a successful re-import needs.
🛠️ Step by step guide
From the Subject Database, export the data.
Review the column names and formats carefully. These define the format your import file must follow.
Keep the export somewhere safe. It is your only way back.
🔬 Explore how it works
Click through this interactive guide to learn the process in seconds.
3. Prepare your import file
Use the exact same format as the export. That includes the first two header lines, not just the first one. Participant data starts on line 3.
Subject ID is the only mandatory column. Every other column can be kept, removed or left empty, and for clarity we recommend keeping only the columns where data needs to be created or updated.
💡 Tip: if you are importing new participants, keep at least the center name, the participant names and their email addresses. Without those the records arrive but are hard to use.
Formatting rules, to follow exactly
Element | Rule |
Column names | Identical to Datacapt, including case, spacing and wording. |
Dates |
|
Multiple choice | Separate values with a vertical bar and no spaces: |
Answer values | Must match the form's options exactly. Watch spaces and capitalization. |
Emails | Unique across subjects. |
Phone numbers | Include the international prefix, for example |
Calculated fields | Do not fill them. Leave the column empty or remove it. Datacapt recalculates from the date of birth after import. |
4. Validate, then import in stages
🛠️ Step by step guide
Review your XLSX file carefully.
If in doubt, ask your CSM for a quick review.
Import one single line first.
Then import a few lines.
Only then import the full file.
Importing in stages is what lets you find a formatting or mapping problem while it affects one subject rather than all of them.
5. Trigger the recalculation
After the import finishes, export all Subject Database data once. That export triggers the recalculation of computed fields and the re-evaluation of the form's conditional logic, which is what makes the database consistent with the updated form.
💡 Tip: this step looks pointless and is not. Until you run that export, calculated fields and conditions reflect the state before your import.
If you are unsure
Contact your Customer Success Manager before proceeding, particularly if your case involves restructuring a form, a live study, or a large dataset.