Quality assurance encompasses the organizational systems, procedures, and activities designed to provide confidence that quality requirements for clinical trials will be fulfilled. QA operates at a strategic level, establishing the framework within which quality is achieved rather than checking individual outputs. This function is independent from trial operations to provide objective oversight and assessment of compliance with quality standards, GCP, and regulatory requirements.

The QA function typically includes developing and maintaining quality management systems, establishing standard operating procedures, conducting internal audits, managing corrective and preventive action programs, and providing compliance training. QA personnel review protocols and essential documents, evaluate vendor qualifications, assess risk management plans, and oversee continuous improvement initiatives. Their independence from operational responsibilities enables objective evaluation of trial conduct.

Quality assurance differs fundamentally from quality control, though the two functions are complementary. While QA focuses on building quality into processes and systems, quality control addresses the verification of specific outputs against requirements. A robust quality management system integrates both functions, with QA establishing the standards and systems that QC activities verify. Together, these functions ensure that clinical trials generate reliable data while protecting participant rights and welfare.