Practice Exam

NOTE: This sample exam is not active: the check-boxes are here to demonstrate the format of the final exam only (i.e. you cannot submit this exam for automatic grading - you have to read the answers below).

1. For aspartate aminotransferase, performance is to be assessed at a decision level slightly above the upper limit of the referenced range. Using the CLIA criteria for acceptable performance in proficiency testing, what would be the allowable total error at this decision level?
a. 10%
b. 15%
c. 20%
d. 5%

2-3. For a lithium method, performance is to be assessed at decision levels of 0.4 mmol/L and 1.50 mmol/L. Using CLIA PT criteria, what would be the allowable total errors at these two decision levels?
 

2. TE_a at 0.4 mmol/L
a. 10%
b. 25%
c. 50%
d. 75%

3. TE_a at 1.5 mmol/L
a. 0.10 mmol/L
b. 0.20 mmol/L
c. 0.30 mmol/L
d. 0.40 mmol/L

4-5 For blood lead, it is of interest to optimize QC performance at decision levels of 10 ug/dL and 45 ug/dL. Using CLIA profiency testing criteria, what would be the allowable total errors at these two decision levels?

4. TE_a at 10 ug/dL
a. 1 ug/dL
b. 2 ug/dL
c. 3 ug/dL
d. 4 ug/dL

5. TE_a at 45 ug/dL
a. 2 ug/dL
b 4 ug/dL
c. 4.5 ug/dL
d. 5 ug/dL

6-7. Given the cholesterol data from a method evaluation study, a standard deviation of 3.0 mg/dL was calculated for a control having a mean of 200 mg/dL. The regression equation was Y = 4.0mg/dL + 1.01X for the data in a method comparison experiment.

6. What is the CV of the method?
a. 3.0 %
b. 2.0 %
c. 1.5 %
d. 3.0 mg/dL

7. What is the method bias at a decision level of 200 mg/dL?
a. 2 mg/dL or 1%
b. 4 mg/dL or 2%
c. 6 mg/dL or 3%
d. 10 mg/dL or 5%

8-12. Given a cholesterol method where the CV is 2.0% and bias is 2.0% and the laboratory is using a Levey-Jennings chart with 3SD limits and N of 2, assess the expected performance of the QC procedure. Assume that the quality requirement is 10% at a decision level of 200 mg/dL.

8. What is the critical systematic error that needs to be detected?
a. 20 mg/dL
b. 2.35s
c. 1.68s
d. 0.68s

9. What is the expected probability of detecting the critical systematic errror?
a. 30% or less
b. about 50%
c. about 70%
d. greater than 90%

10. What is the expected probability of false rejection?
a. 1% or less
b. 2-3%
c. 5%
d. 9%

11. What is your assessment of the adequacy of this QC procedure?
a. Almost perfect
b. Too high false rejection rate
c. Too low error detection rate
d. Too low false rejection rate

12. What would be your recommendation for a Total QC strategy?
a. High P_ed strategy (depend on statistical QC)
b. Moderate P_ed strategy (balance SQC with other QC and QI)
c. Low P_ed strategy (depend on other QC and make QI a priority)

13-15. Given an analyzer that is being evaluated for glucose, the method shows a CV of 1.5 % at a level of 110 mg/dL and a bias of 3.0%.

13. What is the CLIA PT quality requirement for glucose at a level of 110 mg/dL?
a. 10%
b. 6 mg/dL
c. 10 mg/dL
d. 2%

14. What QC procedure is appropriate to achieve 90% error detection of the critical SE?
a. 1_2s with N=2
b. 1_2.5s with N=2
c. 1_3s with N=2
d. 1_3.5s with N=2

15. What Total QC strategy would you recommend?
a. High P_ed strategy (depend on statistical QC)
b. Moderate P_ed strategy (balance SQC with other QC and QI)
c. Low P_ed strategy (depend on other QC and make QI a priority)

16-18. In another application, a method for erythrocyte counts gives a CV of 1.0% and a bias of 0.0% at a decision level of 6 M/uL.

16. What is the CLIA PT quality requirement for erythrocyte counts?
a. 10%
b. 15%
c. 7%
d. 6%

17. What QC procedure is appropriate to achieve 90% error detection of critical SE?
a. 1_2s with N=3
b. 1_2.5s with N=3
c. 1_3s with N=3
d. 1_3s with N=6

18. What Total QC strategy would you recommend?
a. High P_ed strategy (depend on statistical QC)
b. Moderate P_ed strategy (balance SQC with other QC and QI)
c. Low P_ed strategy (depend on other QC and make QI a priority)

19. The selection of QC procedures for glucose and erythrocyte count in the questions above is most readily and easily carried out using which QC planning tool?
a. Power function graphs
b. Critical-error graphs
c. OPSpecs charts
d. QC Selection Grids

20. Given a clinical quality requirement in the form of a medically important change, it is necessary to have access to:
a. The OPSpecs Manual
b. Normalized OPSpecs charts
c. An interactive QC Selection Grid calculator
d. QC Validator computer program

21-23. For cholesterol, guidelines for clinical interpretation suggest that a difference of 40 mg/dL is a significant change for an individual whose homestatic set point is at 200 mg/dL. Given that the intra-individual biological variation is 6.5%, apply the QC planning process to assess this situation.

21. In selecting an appropriate QC procedure, the QC planning process should be driven by a quality requirement in the form of:
a. Allowable total error of 10%
b. Decision interval of 40 mg/dL at 200 mg/dL, or 20%
c. Biological total error goal of 8.5%
d. Allowable imprecision and inaccuracy specifications of 3.0 %

22. Given a cholesterol method with a CV of 2.0% and a bias of 1.0%, an appropriate QC procedure would be:
a. 1_2s with N=2
b. 1_2.5s with N=2
c. 1_3s with N=2
d. 1_3.5s with N=2

23. What Total QC strategy would you recommend?
a. High P_ed strategy (depend on statistical QC)
b. Moderate P_ed strategy (balance SQC with other QC and QI)
c. Low P_ed strategy (depend on other QC and make QI a priority)

24. The QC desired for use with a glucose method is the 1_3s rule with N=2. Given an analytical quality requirement of 10%, what method CV is necessary (if bias is 0.0%)?
a. 2.2%
b. 1.8%
c. 1.5%
d. 1.0%

25. Specifications for allowable imprecision can be determined from which QC planning tool?
a. power function graphs
b. critical-error graphs
c. OPSpecs charts

Answers
1.c
2.d
3.c
4.d
5.c
6.c
7.c
8.b
9.b
10.a
11.c
12.b
13.a
14.b
15.a
16.d
17.c
18.a
19.c
20.d
21.b
22.c
23.a
24.b
25.c