STP Quality Management 5 — Questions and Answers
Question 1: A laboratory implements a new centrifuge. Which pre-analytical quality consideration is MOST directly affected by centrifuge speed and time settings?
- Sample labeling accuracy
- Adequate separation of serum or plasma from cells (Correct answer)
- Request form completeness
- Patient identification verification
Correct answer: Adequate separation of serum or plasma from cells
Centrifuge speed (RCF) and duration determine whether serum or plasma is adequately separated from cellular components, directly affecting sample quality.
Question 2: In risk management for laboratories (ISO 22367), what is the formula used to calculate a Risk Priority Number (RPN) in a Failure Mode and Effects Analysis (FMEA)?
- Severity × Detectability
- Occurrence × Detectability
- Severity × Occurrence × Detectability (Correct answer)
- Severity + Occurrence + Detectability
Correct answer: Severity × Occurrence × Detectability
RPN = Severity × Occurrence × Detectability; higher RPNs identify failure modes requiring the most urgent mitigation action.
Question 3: What is the key difference between 'validation' and 'verification' of a laboratory method?
- Validation is done by manufacturers; verification is done by users to confirm performance in their setting (Correct answer)
- Verification is more rigorous and requires more samples than validation
- Validation applies only to qualitative methods; verification applies to quantitative methods
- They are synonymous terms under CLIA regulations
Correct answer: Validation is done by manufacturers; verification is done by users to confirm performance in their setting
Manufacturers validate methods by establishing performance claims; laboratories verify those claims are achieved in their specific environment before clinical use.
Question 4: When reviewing a Pareto chart of laboratory errors, the bars represent which of the following?
- Error types arranged by time of occurrence
- Error types ranked in descending order of frequency with a cumulative percentage line (Correct answer)
- Error severity scores plotted against detection rate
- Monthly error counts compared between two laboratories
Correct answer: Error types ranked in descending order of frequency with a cumulative percentage line
A Pareto chart ranks defect categories from most to least frequent with a cumulative percentage line, applying the 80/20 rule to prioritize improvement efforts.
Question 5: A critical value (panic value) result is generated in the laboratory. What is the MOST important next step according to quality and patient safety standards?
- Repeat the sample using a different analyzer before communicating
- Immediately communicate the result to the responsible clinician and document the notification (Correct answer)
- File an incident report and quarantine the patient's remaining samples
- Archive the result and await the clinician's call
Correct answer: Immediately communicate the result to the responsible clinician and document the notification
Critical values must be communicated immediately to the responsible clinician, with the notification documented including time, recipient, and read-back confirmation.
Question 6: Which term describes the ability of an analytical method to measure only the analyte of interest and not cross-react with similar substances?
- Sensitivity
- Specificity / Analytical specificity (Correct answer)
- Reproducibility
- Robustness
Correct answer: Specificity / Analytical specificity
Analytical specificity is the ability of a method to measure only the target analyte without interference from structurally similar compounds or matrix components.
Question 7: In a laboratory quality audit, the auditor finds that corrective actions from a previous audit cycle were documented but never implemented. This BEST represents a failure in which quality system element?
- Document control
- Corrective and Preventive Action (CAPA) effectiveness monitoring (Correct answer)
- Personnel training records
- Equipment maintenance scheduling
Correct answer: Corrective and Preventive Action (CAPA) effectiveness monitoring
CAPA systems require not only documenting actions but verifying their implementation and effectiveness; failure to implement documented actions reflects a CAPA monitoring breakdown.
STP Quality Management 5
A laboratory implements a new centrifuge.
Which pre-analytical quality consideration is MOST directly affected by centrifuge speed and time settings?