How would you respond to inconsistent source and eCRF data?

Short answer

First identify the discrepancy and whether it affects participant safety, eligibility or a critical endpoint. Compare the eCRF with the original, attributable source record, raise a documented query and obtain a justified correction without obscuring the audit trail.

Why

The purpose of source-to-eCRF checks is to preserve the meaning and provenance of clinical data. Start with the original record and ask whether the discrepancy is a transcription error, a definition problem, a timing difference or a genuine source inconsistency. A temperature documented at 08:05 and entered as 8.5 should not simply be replaced until the correct units and source are confirmed.

Protect the participant if the mismatch suggests a safety or dosing issue. Follow data-management procedures for queries, authorized corrections, reason-for-change documentation and audit-trail preservation. Escalate patterns that suggest a broader process or training problem.

Final reconciliation should leave a traceable explanation of which value is accepted and why, not just matching numbers across two systems.

An example

Source notes record a blood sample at 09:30 but the eCRF says 08:30. The team checks the time zone, sampling log and laboratory label before approving a traceable change.

Common mistakes

Editing the source document merely to agree with the eCRF or assuming every disagreement is a simple typo

The interviewer might ask next

Which discrepancies would you escalate immediately rather than queue for routine cleaning?