A participant says they entered the wrong value in their ePRO diary. How should it be corrected?

Why

ePRO data differ from case report form data in who owns them. The participant is the originator, and the investigator reviews but does not manage the data, which are often hosted by a vendor. EMA's computerised systems guideline notes that participants usually cannot correct entries in the app, so sponsors need a procedure for changes, initiated by the participant or by site staff.

The procedure must not prevent justified changes, and site-initiated changes need solid source, such as a phone note or email made right after the participant reported the error. The guideline also warns that corrections should not be made much later without good reason, because contemporaneous entry is what limits recall bias. So if a participant calls the next morning to say they tapped 8 instead of 3 for pain, the site records the call, and the change goes through the vendor's controlled process with the original value preserved.

If the participant raises it three weeks later, the case for changing it is weaker. Investigators also need timely access to ePRO data so they can spot safety signals hidden in diaries.