What is it? Why is it important?
During the final database lock actions are taken to prevent further changes to the study database. The final lock is performed at the end of the study once:
- All required data has been collected and entered into the study database (eCRF)
- Data has been checked and corrected for missing and incorrect entries
- Data queries triggered by the study monitor have been resolved by study staff
- The SP-INV or Site-INV has signed off the eCRF, confirming data to be correct and complete
After final lock:
- Changes to the study database (eCRF) is no longer possible
- The locked data is ready for export and statistical analysis
In the event of a multi-centre study, respective locks must be performed or adapted based on study progression at individual study sites. Some sites might complete data collection earlier than others. Thus, individual site-specific locks might precede the final global lock of the study.
Studies with large amounts of data or lasting over long periods might profit from interim locks, as this will:
- Reduce the amount of work during final lock
- Allow for data quality checks to be performed in close proximity of the originally collected data
What do I need to do?
- Final database locks require structured and well-defined procedures
- Document database locking procedures that must be followed in study SOPs/WIs
- If applicable, make special provisions based on individual site locks versus the global lock of the study
- Document time and date of database lock to prove that:
- Statistical analysis took place after database lock
- If applicable, blinded randomisation codes were broken after database lock
In order to avoid chaos and facilitate database lock, plan ahead and ensure that:
- Data entries are performed on an ongoing basis, while data is still “fresh”. Thus, Site-INVs can sign off any complete and correct data on an ongoing basis, so as not postpone this task to the very end
- External data providers (e.g. laboratories) are informed head of time of upcoming locks in order for them to ensure that their data becomes integrated into the main study database
- Adequate time for data monitoring and resolution of data queries is given
Hindsight management of large volumes of data carries a significant risk to the quality and integrity of study data.
Where can I get help?
Your local CTU↧ can support you with experienced staff regarding this topic
Basel, Clinical Trials Unit, CTU, dkf.unibas.ch
Bellinzona, Clinical Trials Unit, CTU-EOC, www.ctueoc.ch
Bern, Clinical Trials Unit, CTU, www.ctu.unibe.ch
Geneva, Clinical Research Center, CRC, crc.hug.ch
Lausanne, Clinical Research Center, CRC, www.chuv.ch
St. Gallen, Clinical Trials Unit, CTU, www.kssg.ch
Zürich, Clinical Trials Center, CTC, www.ctc.usz.ch
ICH-GCP E6(R2) – see in particular guidelines
- 5.5. Trial management, data handling, and record-keeping