CHAPTER 5: QUALITY ASSURANCE IN HEMATOLOGY AND HEMOSTASIS TESTING

Question 1

(1) What procedure is employed to validate a new assay?

a. Comparison of assay results to a reference method
b. Test for assay precision
c. Test for assay linearity
d. All of the above

Answer 1

d. All of the above

Question 2

(2) You validate a new assay using linear regression to compare assay calibrator results with the distributor’s published calibrator results. The slope is 0.99 and the y intercept is +10%. What type of error is present?

a. No error
b. Random error
c. Constant systematic error
d. Proportional systematic error

Answer 2

b. Random error

Question 3

(3) Which is a statistical test comparing means?

a. Bland-Altman
b. Student’s t-test
c. ANOVA
d. Pearson

Answer 3

b. Student’s t-test

Question 4

(4) The acceptable hemoglobin control value range is 13 ± 0.4 g/dL. The control is assayed five times and produces the following five results:

12.0 g/dL
12.3 g/dL
12.0 g/dL
12.2 g/dL
12.1 g/dL

These results are:
a. Accurate but not precise
b. Precise but not accurate
c. Both accurate and precise
d. Neither accurate nor precise

Answer 4

b. Precise but not accurate

Question 5

(5) A WBC count control has a mean value of 6000/uL and a standard deviation of 300/uL. What is the 95.5% confidence interval?

a. 3000 to 9000/uL
b. 5400 to 6600/uL
c. 5500 to 6500/uL
d. 5700 to 6300/uL

Answer 5

b. 5400 to 6600/uL

Question 6

(6) The ability of an assay to distinguish the targeted analyte from interfering substances within the specimen matrix is called:

a. Analytical specificity
b. Analytical sensitivity
c. Clinical specificity
d. Clinical sensitivity

Answer 6

a. Analytical specificity

Question 7

(7) The laboratory purchases reagents from a manufacturer and develops an assay using standard references. What FDA category is this assay?

a. Cleared
b. Home-brew
c. Research use only
d. Analyte-specific reagent

Answer 7

d. Analyte-specific reagent

Question 8

(8) A laboratory scientist measures prothrombin time for plasma aliquots from 15 healthy males and 15 healthy females. She computes the mean and 95.5% confidence interval and notes that they duplicate the manufacturer’s statistics within 5%. This procedure is known as:

a. Confirming linearity
b. Setting the reference interval
c. Determining the therapeutic range
d. Establishing the reference interval by transference

Answer 8

d. Establishing the reference interval by transference

Question 9

(9) You purchase a preserved whole blood specimen from a distributor who provides the mean values for several complete blood count analytes. What is this specimen called?

a. Normal specimen
b. Calibrator
c. Control
d. Blank

Answer 9

c. Control

Question 10

(10) You perform a clinical efficacy test and get the following
results:

https://drive.google.com/file/d/1Afb6n7OPv80jwS_ucc-MwfU0LvDSUFHd/view

What is the number of false-negative results?
a. 40
b. 10
c. 5
d. 45

Answer 10

c. 5

Question 11

(11) What agency provides external quality assurance (proficiency) surveys and laboratory accreditation?

a. Clinical Laboratory Improvement Advisory Committee (CLIAC)
b. Centers for Medicare and Medicaid Services (CMS)
c. College of American Pathologists (CAP)
d. Joint Commission

Answer 11

c. College of American Pathologists (CAP)

Question 12

(12) What agency provides continuing medical laboratory education?

a. Colorado Association for Continuing Medical Laboratory Education (CACMLE)
b. Clinical Laboratory Improvement Advisory Committee (CLIAC)
c. Centers for Medicare and Medicaid Services (CMS)
d. College of American Pathologists (CAP)

Answer 12

a. Colorado Association for Continuing Medical Laboratory Education (CACMLE)

Question 13

(13) Regular review of blood specimen collection quality is an example of:

a. Postanalytical quality assurance
b. Preanalytical quality assurance
c. Analytical quality control
d. External quality assurance

Answer 13

b. Preanalytical quality assurance

Question 14

(14) Review of laboratory report integrity is an example of:

a. Preanalytical quality assurance
b. Analytical quality control
c. Postanalytical quality assurance
d. External quality assurance

Answer 14

c. Postanalytical quality assurance

Question 15

(15) When performing a receiver operating curve analysis, what parameter assesses the overall efficacy of an assay?

a. Area under the curve
b. Performance limit (threshold)
c. Positive predictive value
d. Negative predictive value

Answer 15

a. Area under the curve

Question 16

(16) You require your laboratory staff to annually perform manual lupus anticoagulant profiles on a set of plasmas with known values. This exercise is known as:

a. Assay validation
b. Proficiency testing
c. External quality assessment
d. Pre-pre analytical variable assay

Answer 16

b. Proficiency testing