MT 520: MORE SAMPLE EXAM QUESTIONS

1. If selecting 2 control materials for a glucose method, which would you select ?

• A. 50 mg/dL
• B. 100 mg/dL
• C. 150 mg/dL
• D. 200 mg/dL
• E. 250 mg/dL
• F. 300 mg/dL

2. In calculating control limits for a control chart, it is best to use:

• A. the mean and SD quoted on the package insert
• B. the mean and SD determined experimentally by the manufacturer
• C. the mean and SD determined by the laboratory
• D. the target mean and SD determined by proficiency testing

3. The most common QC practice in use today in clinical laboratories in the USA would likely be:

• A. Levey-Jennings chart with 3SD limits
• B. Multirule QC procedure
• C. Shewhart mean/range charts
• D. Levey-Jennings chart with 2SD limits

4. A Levey-Jenning's chart with 3SD limits may have a problem with:

• A. High probability for false rejection
• B. Low probability for false rejection
• C. High probability for error detection
• D. Low probability for error detection

5. The probability for false rejection generally decreases as:

• A. N increases
• B. Standard deviation increases
• C. Mean increases
• D. Control limit increases (widens)

6. The QC practice employing a Levey-Jennings control charts for 2 materials with 2 SD control limits would be indicated by:

• A. 2-2SD
• B. 1_2s with N=2
• C. 2_2s
• D. 2S2N

7. In run number 5 on the preceding control chart, which of the following is the best interpretationof the control measurements?

• A. No problem
• B. Random error problem
• C. Systematic error problem

8. Which of the following multi-rule procedures will offer the best detection of systematic errors?

• A. 1_3s/2_2s
• B. 1_3s/2_2s/R_4s
• C. 1_3s/2_2s/4_1s
• D. 1_3s/R_4s

9. A good adaptation of the multi-rule QC procedure when N=3 is to use:

• A. (2of3)_2s rule instead of 2_2s
• B. 8_x rule instead of 10_x
• C. R_0.01 rule instead of R_4s
• D. 4_1s as a "warning" rule
• E. 10_x as a "warning" rule

10. One of the advantages of the 13s/22s/R4s/41s/10x- multi-rule procedure compared to a single rule procedure using 2SD control limits is:

• A. Lower probability for false rejection
• B. Lower probability for error detection
• C. High probability for false rejection
• D. High probability for error detection

11. Given control results from a multi-test analyzer are presented as z-scores, which of the following indicates a test with a problem?

• A. z= -.05
• B. z= 1.5
• C. z= +3.2
• D. z= -1.1
• E. z= +1.5

12. Given proficiency testing results with SDI values of 1.5, -0.8, +2.9, -0.3 and +0.8 for a group of 5 cholesterol samples, what would you conclude?

• A. All is well!
• B. Problem with sample 2 (SDI of 2.9)
• C. Possible precision problem with this test
• D. Possible accuracy problem with this test

13. Given a run that is out-of-control, the best action is to:

• A. Repeat the controls
• B. Try new controls
• C. Inspect the method for problems
• D. Inspect the QC procedure for problems