Quality control in clinical trials refers to the operational techniques and activities implemented within the clinical trial process to ensure that data are generated, documented, and reported in compliance with the study protocol, regulatory requirements, and Good Clinical Practice (GCP) guidelines. It involves systematic checks at each stage of the trial—from protocol development and site initiation to patient safety monitoring, data collection, and reporting—to verify accuracy, consistency, and reliability.
Quality control measures include ongoing review of trial documentation, monitoring of investigational sites, data verification, and adherence to predefined procedures and standards. Unlike quality assurance, which focuses on system-wide processes, quality control emphasizes detecting and correcting errors in real time to maintain the integrity of the study. Effective quality control contributes to patient safety, credible study outcomes, and regulatory acceptance by reducing risks of bias, variability, and non-compliance.