CC1: QUALITY ASSURANCE AND QUALITY CONTROL

Question 1

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 1

Answer: B) Ensure accurate and reliable results

Question 2

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 2

Answer: B) Ensuring precision and accuracy in results

Question 3

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 3

Answer: C) Increase the number of test results per hour

Question 4

What is another name for Internal Quality Control?
A) External QC
B) Intralab QC
C) Proficiency Testing
D) Standard QC

Answer 4

Answer: B) Intralab QC

Question 5

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 5

Answer: B) Comparing results with other laboratories

Question 6

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 6

Answer: C) Must resemble human samples

Question 7

Which type of reagent contains only one analyte?
A) Control
B) Standard
C) Blank
D) Matrix

Answer 7

Answer: B) Standard

Question 8

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 8

Answer: B) Detect disease in healthy individuals

Question 9

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 9

Answer: B) It is more accurate and expensive

Question 10

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 10

Answer: B) The accuracy of the test

Question 11

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 11

Answer: B) A person is healthy, but the test is positive

Question 12

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 12

Answer: B) Identify all diseased individuals correctly

Question 13

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 13

Answer: B) Identify individuals who do NOT have the disease

Question 14

What does “Standard Deviation” measure?
A) Accuracy
B) Precision
C) Speed of testing
D) Test cost

Answer 14

Answer: B) Precision

Question 15

Which chart is commonly used in quality control?
A) Scatter plot
B) Levey-Jennings chart
C) Pie chart
D) Kaplan-Meier chart

Answer 15

Answer: B) Levey-Jennings chart

Question 16

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 16

Answer: B) The control values gradually increase or decrease over time

Question 17

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 17

Answer: A) Monitor random and systematic errors

Question 18

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 18

Answer: A) 10 consecutive values are above or below the mean

Question 19

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 19

Answer: A) Limit of Detection

Question 20

Which error occurs randomly and unpredictably?
A) Systematic error
B) Constant error
C) Proportional error
D) Random error

Answer 20

Answer: D) Random error

Question 21

Quality assurance focuses only on external quality control.

Answer 21

False

Question 22

Precision refers to how close repeated measurements are to each other.

Answer 22

True

Question 23

Systematic errors are unpredictable and occur randomly.

Answer 23

False

Question 24

The Levey-Jennings chart helps detect trends and shifts in quality control data.

Answer 24

True

Question 25

A shift in a control chart means the values cluster on one side of the mean.

Answer 25

True

Question 26

Specificity measures the ability to detect diseased individuals.

Answer 26

False

Question 27

Sensitivity measures the test's ability to detect small amounts of analyte.

Answer 27

True

Question 28

Westgard rules only apply to random errors.

Answer 28

False

Question 29

A reagent blank contains no analyte.

Answer 29

True

Question 30

The purpose of quality control is to maintain the accuracy and precision of laboratory tests.

Answer 30

True

Question 31

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 31

Answer: C) Calibration issue

Question 32

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 32

Answer: A) To assess the accuracy of a laboratory compared to other laboratories

Question 33

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 33

Answer: A) Measurement consistently off by 5 mg/dL

Question 34

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 34

Answer: C) Intralab QC

Question 35

Which parameter is used to measure how well a test detects only the intended analyte? A) Sensitivity B) Specificity C) Reliability D) Precision

Answer 35

Answer: B) Specificity

Question 36

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 36

Answer: B) Systematic Error

Question 37

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 37

Answer: B) Two consecutive control values exceed ±2SD on the same side of the mean

Question 38

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 38

Answer: B) One result is beyond +2SD and another is beyond -2SD

Question 39

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 39

Answer: C) Instrument calibration drift

Question 40

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 40

Answer: B) Low specificity