Database lock is the moment the data becomes final for analysis. Getting there depends on everything before it: queries closed, critical data verified, casebooks signed. Capture lets data managers freeze and lock data as they go, so lock is a confirmation, not a scramble.
Free sandbox · No credit card · 21 CFR Part 11 aligned
Open queries
3
Fields verified
98%
Casebooks signed
46/48
0 open
Key points
The approach
The traditional path to lock is a long sprint after the last visit: chase every open query, verify the remaining critical fields, collect investigator signatures, reconcile safety data and hope nothing new appears. The work is the same whether it happens at the end or throughout the study, but doing it at the end puts it all on the critical path.
Progressive locking spreads it out. As each visit is cleaned and verified, the data manager freezes or locks it, so the remaining work at the end is small and visible. Sites stop being asked about data from a year ago, and the final lock becomes a check that nothing is outstanding. See the database lock glossary entry for the definitions.
Studies with interim analyses often need a snapshot or interim lock of data up to a cut-off date. Define the cut-off, the data included and the cleaning standard for the interim in the data management plan, and lock the relevant data before the snapshot is taken.
Lock readiness
| Item | Typical owner | Evidence |
|---|---|---|
| All queries resolved or closed | Data manager, sites | Query list with no open items |
| Critical data verified | Monitors | SDV status for the fields in the monitoring plan |
| Investigator sign-off | Principal investigators | Signed casebooks |
| Medical coding complete | Coders, medical monitor | Coded AEs, medical history and medications |
| SAE reconciliation | Safety and data management | Safety database and clinical database agree |
| External data reconciled | Data manager | Central lab, imaging and other vendor data matched |
| Protocol deviations reviewed | Clinical team | Final deviation list and classification |
Your data management plan defines the exact criteria and approvals for lock.
In Capture
Data managers freeze and lock data field by field or in bulk. Unfreezing or unlocking requires a reason, and every change is recorded in the field-level audit trail with who, when and why. Queries, source data verification and principal investigator sign-off of the casebook happen in the same system, so the evidence for lock is in one place.
Weight changed 68.0 to 68.5 kg
Site coordinator · Reason: Transcription error
Query Q-0014 answered on Weight
Site coordinator · Reason: Source checked
Vital signs form locked
Data manager · Reason: Visit cleaned
Try the workflow on sample data in the free sandbox.
From last visit to lock
All scheduled data is due. Sites enter remaining data within the agreed timeline.
Edit check queries and manual review queries are resolved; monitors complete verification of critical data.
Medical coding is finalised, SAEs reconciled with the safety database and external data matched.
Principal investigators sign their casebooks.
Data is locked after the approvals in the data management plan, and the final export is taken.
After lock
Sometimes an error is found after lock. The data management plan should define who can approve an unlock, what justification is needed, how the change is made and reviewed, and how the database is re-locked. Every step should leave a record, because inspectors will ask why locked data changed.
Unlocks are also a quality signal. A pattern of post-lock changes usually points to gaps in cleaning or verification earlier in the study, which is worth fixing in the next study's data management plan.
Planning
In the data management plan, with approvers.
Freeze or lock cleaned visits during the study.
Fields that must be verified before lock.
SAE and external data reconciled regularly, not only at the end.
Investigators know when casebooks will be ready to sign.
Who approves, how changes are documented, how re-lock works.
The point at which trial data is declared final for analysis. After lock, changes require a documented unlock.
A freeze protects data from routine changes while final review continues; a lock makes it final. Exact definitions vary by organisation and are set in the data management plan.
Data managers freeze and lock data, field by field or in bulk.
Only after unlocking, which requires a reason. Every change is recorded in the audit trail.
It depends on how clean the data is at the last visit. Studies that clean and verify continuously can lock in weeks rather than months.
Yes, in the free sandbox with sample data.
Freeze and lock as you go. Free sandbox.