Quality Control & Assurance in Laboratory Practices Flashcards
7 cards from real CMLA practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Quality Control & Assurance in Laboratory Practices flashcards as text
A laboratory assistant notices the QC mean has gradually increased over 30 days. What is the most likely cause?
Answer: Reagent deterioration or calibration drift
A gradual shift in the QC mean over time typically indicates reagent deterioration, instrument drift, or a calibration issue requiring investigation.
What action should be taken when proficiency testing results are found to be unacceptable?
Answer: Document and submit a corrective action plan to the accrediting body
Unacceptable PT results require documentation, root cause analysis, and a corrective action plan submitted to the accrediting organization.
Which of the following best describes the difference between accuracy and precision in laboratory QC?
Answer: Accuracy measures closeness to true value; precision measures reproducibility
Accuracy refers to how close a result is to the true value, while precision refers to how reproducible repeated measurements are.
A calibration verification requires testing patient-like samples at a minimum of how many concentration levels?
Answer: Three levels (low, mid, high)
CLIA requires calibration verification at a minimum of three levels (low, mid, and high) spanning the reportable range.
Which QC approach involves using patient data statistics such as the average of normals (AON) to monitor analytical performance?
Answer: Patient-based real-time QC (PBRTQC)
Patient-based real-time QC uses the statistical distribution of patient results to detect systematic errors without relying solely on traditional controls.
When a new reagent lot is placed into service, the laboratory should first:
Answer: Perform parallel testing with the old and new lot before switching
Parallel testing of old and new reagent lots ensures equivalent performance before transitioning to the new lot to protect patient safety.
The R-4s Westgard rule is triggered when:
Answer: The range between two controls within the same run exceeds 4 standard deviations
The R-4s rule flags a run when the difference between the highest and lowest control values within one run is greater than 4 standard deviations, indicating random error.