QC Audits Are Performed Prior to Hard Database Lock to Ensure the Validity of the Trial Database

QC Audits

Pharmaceutical companies recognize the benefits of carefully managing the quality of data from their drug development and clinical trials. To ensure clinical data accuracy and integrity it is necessary to thoroughly review these data, to assess the validity of outlying data points, and to carefully document query identification and resolution throughout a study's duration. QC Audits have a major part to play in this process.

Most QC audits are performed prior to hard database lock to ensure the validity of the clinical trial database.


Quality Assurance or QA: the systematic, independent examination of all clinical trial-related documents and activities. These QA audits examine whether the activities performed were appropriately conducted, and whether the data were accurately generated, recorded, analysed, and reported according to Standard Operating Procedures (SOPs), the protocol, and Good Clinical Practice (GCP).

Quality Control or QC: the periodic operational checks within each department to confirm that the clinical data are generated, handled, analysed and reported according to SOPs, the protocol, and GCP.

Data Management

The accuracy of the data entry performed during the data management process is verified by an independent secondary entry of the data in addition to the primary entry, and a subsequent comparison of the datasets produced by the primary and secondary entries in order to highlight discrepancies. The data are then validated electronically using validation check programs, and queries are produced and subsequently resolved via manual review. At the end of the process the database is audited against the CRFs. The Tables, Listings and Graphs (TLGs or TFLs) that are programmed as part of the statistical analysis of the data are also inspected to ensure accuracy, as is the CSR text.

Statistical Analysis

After a QC review of a study database has taken place, the database is exported to SAS in order that the data listing, statistical summary and analysis programming can take place in order to produce the TLGs for inclusion in the CSR. The TLGs undergo QC and validation by independent programming of the same summary statistics and analyses. All discrepancies discovered are then resolved.

QA for the statistical summary and analysis process ensures that SAS programs are validated for the production of all TLGs by checking that all the study requirements were addressed. QA also confirms that the statistical analysis plan (SAP) was written following SOP-defined processes, and that all SAPs have the appropriate approvals.

In addition to a review of the statistical summary and analysis process, QC also inspects a seleced sample of TLGs. Sampled numbers from the summary tables are checked against data listings, and tables are checked against the formats specified by the SAP.