CC1: QUALITY ASSURANCE AND QUALITY CONTROL Flashcards
What is the primary goal of Quality Assurance in a laboratory?
A) Ensure cost efficiency
B) Ensure accurate and reliable results
C) Increase the number of tests performed
D) Reduce the use of reagents
Answer: B) Ensure accurate and reliable results
Quality Control focuses on:
A) Testing patient samples only
B) Ensuring precision and accuracy in results
C) Increasing laboratory efficiency
D) Reducing test costs
Answer: B) Ensuring precision and accuracy in results
Which of the following is NOT an objective of Quality Control?
A) Check the stability of the machine
B) Check the quality of reagents
C) Increase the number of test results per hour
D) Identify technical/clerical errors
Answer: C) Increase the number of test results per hour
What is another name for Internal Quality Control?
A) External QC
B) Intralab QC
C) Proficiency Testing
D) Standard QC
Answer: B) Intralab QC
External Quality Control (Interlab QC) is best described as:
A) Testing control samples daily
B) Comparing results with other laboratories
C) Checking machine stability
D) Using the same reagents for all tests
Answer: B) Comparing results with other laboratories
What is a characteristic of an ideal QC material?
A) Must contain unknown analyte concentrations
B) Should be expensive and complex
C) Must resemble human samples
D) Must always contain infectious agents
Answer: C) Must resemble human samples
Which type of reagent contains only one analyte?
A) Control
B) Standard
C) Blank
D) Matrix
Answer: B) Standard
What is the primary purpose of a screening test?
A) Diagnose a disease
B) Detect disease in healthy individuals
C) Determine treatment plans
D) Measure exact analyte levels
Answer: B) Detect disease in healthy individuals
A diagnostic test is different from a screening test because:
A) It is done only on healthy individuals
B) It is more accurate and expensive
C) It does not require reagents
D) It has no clinical significance
Answer: B) It is more accurate and expensive
What does “Validity” measure in quality control?
A) The cost of the test
B) The accuracy of the test
C) The precision of the test
D) The speed of the test
Answer: B) The accuracy of the test
Which of the following represents a False Positive (FP)?
A) A person has a disease, but the test is negative
B) A person is healthy, but the test is positive
C) A person does not have a disease, and the test is negative
D) A person has a disease, and the test is positive
Answer: B) A person is healthy, but the test is positive
Sensitivity refers to a test’s ability to:
A) Detect only large amounts of analyte
B) Identify all diseased individuals correctly
C) Detect only normal levels of analyte
D) Identify individuals without disease
Answer: B) Identify all diseased individuals correctly
Specificity refers to a test’s ability to:
A) Detect any kind of interference
B) Identify individuals who do NOT have the disease
C) Measure only large analyte concentrations
D) Give the same result every time
Answer: B) Identify individuals who do NOT have the disease
What does “Standard Deviation” measure?
A) Accuracy
B) Precision
C) Speed of testing
D) Test cost
Answer: B) Precision
Which chart is commonly used in quality control?
A) Scatter plot
B) Levey-Jennings chart
C) Pie chart
D) Kaplan-Meier chart
Answer: B) Levey-Jennings chart
A trend in a Levey-Jennings chart is identified when:
A) The control values show a sudden spike
B) The control values gradually increase or decrease over time
C) The control values remain within normal limits
D) The control values remain on one side of the mean
Answer: B) The control values gradually increase or decrease over time
Westgard Multirule System is used to:
A) Monitor random and systematic errors
B) Replace external quality control
C) Track reagent expiration dates
D) Predict patient outcomes
Answer: A) Monitor random and systematic errors
What does “10x” mean in the Westgard rules?
A) 10 consecutive values are above or below the mean
B) 10 different analytes are tested at once
C) The mean value increases by 10%
D) A test must be repeated 10 times
Answer: A) 10 consecutive values are above or below the mean
What is the lowest analyte concentration that can be accurately detected?
A) Limit of Detection
B) Accuracy Index
C) Precision Threshold
D) Specificity Limit
Answer: A) Limit of Detection
Which error occurs randomly and unpredictably?
A) Systematic error
B) Constant error
C) Proportional error
D) Random error
Answer: D) Random error
Quality assurance focuses only on external quality control.
False
Precision refers to how close repeated measurements are to each other.
True
Systematic errors are unpredictable and occur randomly.
False
The Levey-Jennings chart helps detect trends and shifts in quality control data.
True
A shift in a control chart means the values cluster on one side of the mean.
True
Specificity measures the ability to detect diseased individuals.
False
Sensitivity measures the test’s ability to detect small amounts of analyte.
True
Westgard rules only apply to random errors.
False
A reagent blank contains no analyte.
True
The purpose of quality control is to maintain the accuracy and precision of laboratory tests.
True
Which of the following is an example of a Systematic Error?
A) Pipetting error
B) Temperature fluctuation
C) Calibration issue
D) Mislabeling of samples
Answer: C) Calibration issue
What is the purpose of proficiency testing in External Quality Control?
A) To assess the accuracy of a laboratory compared to other laboratories
B) To check for reagent contamination
C) To determine the lifespan of laboratory equipment
D) To detect human errors only
Answer: A) To assess the accuracy of a laboratory compared to other laboratories
Which of the following is an example of a Constant Error?
A) Measurement consistently off by 5 mg/dL
B) A temperature spike in the laboratory
C) Random variations in test results
D) Poor sample labeling
Answer: A) Measurement consistently off by 5 mg/dL
Which type of Quality Control is performed daily in laboratories?
A) External QC
B) Proficiency Testing
C) Intralab QC
D) None of the above
Answer: C) Intralab QC
Which parameter is used to measure how well a test detects only the intended analyte?
A) Sensitivity
B) Specificity
C) Reliability
D) Precision
Answer: B) Specificity
Which type of error is caused by factors such as reagent deterioration and instrument calibration issues?
A) Random Error
B) Systematic Error
C) Measurement Bias
D) Human Error
Answer: B) Systematic Error
Which of the following is a violation of the Westgard 22SD rule?
A) One control result exceeds ±3SD
B) Two consecutive control values exceed ±2SD on the same side of the mean
C) Four consecutive control results exceed ±1SD
D) Ten consecutive control values are on the same side of the mean
Answer: B) Two consecutive control values exceed ±2SD on the same side of the mean
What does the “R4SD” rule in Westgard’s Multirule System indicate?
A) Two consecutive results are outside ±2SD
B) One result is beyond +2SD and another is beyond -2SD
C) Four consecutive results are within ±1SD
D) Ten consecutive values fall on one side of the mean
Answer: B) One result is beyond +2SD and another is beyond -2SD
Which of the following is NOT a factor that contributes to Random Error?
A) Pipetting error
B) Temperature fluctuation
C) Instrument calibration drift
D) Reagent instability
Answer: C) Instrument calibration drift
A test method that has a high false positive rate will have:
A) High specificity
B) Low specificity
C) High sensitivity
D) Low sensitivity
Answer: B) Low specificity
