SMB Validation

For clinical data management systems, where does the audit trail begin.... after first entry or after the data has been verified and uploaded to the data management system?

The latter. Clinical research organizations are mandated to comply with 21 CFR Part 11, which requires tracking the activity and ownership of electronic clinical data in audit trails. If you are using Remote Data Entry (RDE) software for data entry, or especially a Web-based RDE, you need to exercise due diligence to protect your data from inadvertent or malicious changes.