What is the primary difference between QA and QC in laboratory testing?

• A. QA concentrates on end-product outcomes; QC ensures process quality.
• B. QA focuses on the overall process quality, while QC uses controls and calibrators to monitor test performance.
• C. QA and QC are the same concept.
• D. QA is only about patient satisfaction.

Answer: (B)

Quality assurance is about the overall quality system and the processes that shape how tests are designed, validated, documented, and audited. It’s preventive and process-oriented, covering things like standard operating procedures, staff training, documentation control, equipment maintenance planning, and participation in proficiency testing to reduce the chance of errors across the entire testing workflow. Quality control, by contrast, is the daily check of the test itself. It uses control materials and calibrators to monitor the performance of assays during each run, ensuring results are accurate and precise and flagging any out-of-spec issues so they can be addressed before reporting.

So, the best choice captures that QA focuses on the overall process quality, while QC uses controls and calibrators to monitor test performance.