Quality Control & Assurance in Testing Flashcards
7 cards from real CLT 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 Testing flashcards as text
A new point-of-care glucose meter is being evaluated for ward use. Correlation with the central laboratory shows r=0.98. The r value PRIMARILY tells you about:
Answer: Strength of linear association between methods
The correlation coefficient r measures the strength of linear association but does not assess agreement or the magnitude of differences between methods.
A laboratory's QC program uses three levels of control: low, normal, and high. The PRIMARY reason for using multiple QC levels is to:
Answer: Detect errors across the entire analytical measurement range
Using multiple QC levels ensures that errors are detected at medically relevant concentrations throughout the analytical range of the assay.
Which of the following BEST describes the purpose of a method's analytical measurement range (AMR)?
Answer: The concentration range over which the method is linear without dilution
The AMR is the range of analyte concentrations that can be directly measured without specimen dilution or concentration and still yield accurate results.
Frozen aliquots of pooled patient serum are used as QC material. After 6 months, QC values for total protein begin trending downward. The MOST likely cause is:
Answer: Protein degradation in the frozen QC matrix
Prolonged frozen storage can cause protein denaturation and degradation in pooled serum QC material, leading to declining values over time.
A laboratory must perform corrective action after a QC failure. Which document MUST be completed and retained?
Answer: Written record of the problem, investigation, and corrective action taken
CLIA requires laboratories to document QC failures, the investigation performed, corrective actions taken, and the outcome of those actions.
A Youden plot (twin plot) is used in proficiency testing to evaluate:
Answer: Both accuracy and precision of two related analytes simultaneously
The Youden plot displays two analyte levels on x and y axes, revealing both the laboratory's accuracy (position relative to group mean) and precision (distance from the group cluster).
Under CLIA, a laboratory that fails the same analyte on two consecutive proficiency testing events must:
Answer: Submit a root-cause analysis and corrective action plan
CLIA requires laboratories that fail PT on the same analyte in two consecutive events or two of three events to perform and document a corrective action plan.