Why is participation in external quality assessment (EQA) included in QC design?

• A. To compare performance to peers and identify bias or drift.
• B. To replace internal QC materials.
• C. To ensure instrument uptime.
• D. To train staff.

Answer: (A)

External quality assessment is included in QC design because it provides an independent benchmark to gauge how your results compare with those of other laboratories. By participating, you can detect bias—where results systematically deviate from the true value—and drift over time, which might not be evident from internal QC alone. EQA reveals differences between labs or instruments and helps ensure accuracy and consistency across the field, not just within a single lab’s procedures. Internal QC materials and rules monitor day-to-day performance, and uptime is about maintaining equipment, while training staff is beneficial but not the primary purpose of EQA.