1. A test has 95% sensitivity and specificity for a disease with a prevalence of 1 in 500. What is the positive predictive value (PPV) of this test?

2. Positive and negative predictive values are dependent in part of all of the following EXCEPT:

3. A company is introducing a new test for detecting a “test choking” gene. 92 people known to be “test chokers” are tested, and 87 are positive. 610 people who are not “test chokers” are tested, and 576 are negative. Based on this information, calculate the sensitivity and specificity of the new test to detect “test chokers.”

4. Levy-Jennings plots are useful for evaluating which of the following types of analytical changes within a testing system in sequential plotting of quality control test results?

5. The image shown for this question is a skewed distribution. The point along the horizontal axis represented by the variable X is best descriptive of which of the following statistical terms?

6. The image shown for this question is a Gaussian distribution. The variable X and the variable Y correspond to what percentage of the data represented under the curve?

7. When evaluating a relative operating characteristic (ROC) curve to compare different tests, which of the following will have the greatest efficiency (correctly classify the largest percentage of patients)? Note: sensitivity is plotted from 0 to 100 on the y-axis, and specificity is plotted from 100 to 0 on the x-axis.

8. If 10 tests were performed on a “healthy” individual, what is the likelihood all of the results will be within the reference range?

9. If the prevalence of the “test chokers” is 1 in 750, what is the positive predictive value of the test described in the previous question?

10. When evaluating a Levy-Jennings plot for random error, shifts, and trends, if present, which would indicate an unstable system?