Source data verification (SDV) is the process of comparing data recorded in case report forms (CRFs) or electronic data capture systems with the original source documents to ensure accuracy, completeness, and reliability. SDV is a critical component of clinical trial monitoring under ICH E6.
What Is Source Data Verification?
SDV involves a monitor reviewing original medical records, laboratory reports, and other source documents to confirm that the data entered into the trial database matches the source. The process covers key data points including subject demographics, eligibility criteria, primary and secondary endpoint assessments, informed consent documentation, and adverse event reports. SDV is central to ensuring data integrity and the credibility of the clinical trial results.
Regulatory Framework
ICH E6 Section 5.18 requires that the monitor verify that the reported trial data are accurate, complete, and verifiable from source documents. The FDA and EMA expect sponsors to perform SDV as part of a risk-based monitoring strategy, where the extent of verification is commensurate with the risk to data integrity and subject safety. 21 CFR Part 312 and the EU Clinical Trials Regulation (536/2014) reinforce these requirements.
Key Requirements
SDV must be performed by qualified Clinical Research Associates (CRAs) who have access to all relevant source records. The sponsor must define the scope of SDV in the monitoring plan, specifying which data fields require 100% verification and which may be verified through targeted or centralized monitoring. Direct access to source documents must be granted by the investigator to the monitor, auditors, and regulatory inspectors.
Documentation
The monitor must document all SDV activities in monitoring visit reports, including the date, data points verified, discrepancies found, and corrective actions taken. Any discrepancies between source data and CRF entries must be resolved and documented through query resolution processes. The Trial Master File (TMF) must contain evidence that SDV was performed according to the monitoring plan.
Conclusion
Source data verification is fundamental to ensuring the reliability of clinical trial data. A risk-based approach to SDV enables efficient allocation of monitoring resources while maintaining data quality. Proper documentation of SDV activities is essential for demonstrating GCP compliance during regulatory inspections.
