After reviewing external QC sample results, what should the laboratory do if performance is unsatisfactory?

• A. Investigate, correct unsatisfactory performance, and record corrective actions.
• B. Ignore results.
• C. Report to client without changes.
• D. Discard the sample.

Answer: (A)

When external quality control results are unsatisfactory, the essential step is to investigate what went wrong, implement corrective actions to fix the issue, and document those actions. This approach ensures the underlying problem is identified—whether it’s instrument calibration, reagent issues, procedural deviations, or environmental factors—and that steps are taken to prevent recurrence. After identifying the cause, you would apply the appropriate fix (recalibrate or repair equipment, replace reagents, retrain staff, adjust procedures, etc.) and then record what was done, by whom, and what the outcome was for future reference. This documentation creates a traceable record showing that the lab maintains quality, meets regulatory or accreditation requirements, and protects patient safety.

Ignoring results, reporting to the client without making changes, or discarding samples without addressing the issue would fail to correct the problem or provide assurance of reliability.