CRF Review and Source Data Verification

Source data verification and CRF review are important clinical trial monitoring and data-quality activities. They help identify errors, inconsistencies, missing information and other issues that could affect participant safety or the reliability of trial results.

Under the current Good Clinical Practice (GCP) framework, data review and verification activities should be proportionate to the risks and characteristics of the clinical trial. Source data verification should therefore not automatically be interpreted as requiring verification of every data point against source records.

Case Report Form Review

A Case Report Form (CRF) is designed to capture protocol-required information that is reported to the sponsor for each trial participant.

CRF review evaluates recorded trial data for issues such as:

• Missing or incomplete information
• Inconsistent data
• Implausible values
• Protocol deviations
• Data requiring clarification
• Inconsistencies between related data fields
• Potential safety or eligibility issues

CRF review may be supported by manual review, programmed data checks, data-management processes and centralised data analytics.

Source Records and Source Data

Source records are original documents, data and records, or certified copies, containing information relating to clinical findings, observations and other trial-related activities.

Examples may include medical records, laboratory reports, pharmacy records, imaging records, electronic health records and other systems or documents in which trial-related information is first recorded.

The protocol should identify the source records and methods of data capture used in the trial where appropriate.

Source Data Review

Source data review is broader than simply comparing individual CRF entries with source records.

It may involve evaluating source records to assess matters such as protocol compliance, participant eligibility, informed consent, safety information, medical oversight and the overall conduct of the clinical trial.

Source data review can therefore provide important context about how the trial is being conducted at an investigator site.

Source Data Verification

Source data verification (SDV) involves comparing reported trial data with relevant source records to evaluate whether the data have been accurately and reliably reported.

SDV may help identify transcription errors, inconsistencies and discrepancies between reported data and the underlying source information.

The extent of SDV should be determined according to the trial’s monitoring strategy and identified risks rather than assuming that all trial data require the same degree of verification.

Risk-Based Approach to Data Verification

Modern clinical trial monitoring focuses monitoring resources on information and processes that are critical to participant safety and the reliability of trial results.

The sponsor should determine the appropriate extent and nature of monitoring based on identified risks.

Current risk-based monitoring principles are described in the ICH E6 Good Clinical Practice guideline.

Depending on the trial, this may involve targeted source data verification, source data review, centralised monitoring, data analytics and other monitoring techniques.

The monitoring strategy may also be modified as knowledge is gained during trial conduct.

Data Queries and Discrepancy Management

When missing, inconsistent or potentially inaccurate data are identified, a data query may be raised for clarification or correction.

Investigator-site personnel should review and respond to queries appropriately. Changes to trial data should be made in accordance with applicable procedures and should maintain appropriate traceability.

Query resolution should focus on obtaining reliable trial data while avoiding unnecessary or repetitive queries that do not meaningfully contribute to participant safety or data reliability.

Electronic Data and Remote Review

Clinical trials increasingly use electronic data-capture systems and other computerized systems.

Where appropriate and permitted, monitoring may involve secure remote review or direct read-only access to relevant source records, data-acquisition tools and essential-record systems.

Access should be appropriately controlled and should protect participant confidentiality in accordance with applicable regulatory requirements, institutional policies and data-security standards.

Documentation of Review and Verification

Monitoring activities and significant findings should be appropriately documented.

Documentation should describe important issues identified during monitoring, actions taken or required, and follow-up through resolution where applicable.

Significant findings may also influence subsequent monitoring activities or indicate that the monitoring strategy should be modified.

For more information on how these activities fit within the broader monitoring strategy, see Routine Site Monitoring.

Importance of CRF Review and Source Data Verification

CRF review and source data verification contribute to reliable clinical trial data and effective sponsor oversight.

However, they form part of a broader monitoring strategy that can also include source data review, centralised monitoring, data analytics, communication with investigator sites and targeted on-site or remote monitoring.

A proportionate, risk-based approach helps direct monitoring resources toward the data and processes that are most important for protecting participants and ensuring reliable trial results.

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