Quality control represents the tactical implementation of quality verification activities throughout clinical trial conduct. While quality assurance establishes the systems and standards for quality, quality control involves the specific checks and reviews that verify compliance with those standards. QC activities are typically embedded within operational processes rather than functioning as an independent oversight function.

QC activities in clinical trials take many forms depending on the specific processes being controlled. Data quality control includes edit checks in electronic data capture systems, medical coding review, and manual verification of critical data points. Document quality control encompasses review of essential documents for completeness and accuracy before filing. Process quality control involves verification that procedures are followed correctly, such as confirming that samples are processed according to specified protocols.

The integration of quality control into routine operations represents a key principle of modern quality management. Rather than relying solely on end-stage inspection to identify problems, effective QC builds verification into each process step. This approach enables earlier detection of issues, reduces rework, and produces higher quality outputs. The specific QC activities implemented should be proportionate to the risks associated with each process, consistent with the risk-based approach emphasized throughout ICH E6(R3).