Question

1. Disease X has a low prevalence in population A, and high prevalence in population B. Which of the following is true? (2 points)
   1. The positive predictive value of a screening test will be higher in population B compared to population A.
   2. The positive predictive value of a screening test will be higher in population A compared to population B.
   3. The predictive value of a test is not related to the prevalence of disease in a population.
   4. None of the above.

2. If a test has a sensitivity of 100%, it means: (2 points)
   1. That the test identifies everyone with the disease and never flags healthy people as having the disease.
   2. That the test identifies everyone with the disease, but it may mistakenly flag some healthy people as having the disease.
   3. It should not be used as a screening test because it may have some false positives.
   4. All of the above.

3. At a population level, which of the following aspects of a screening test cannot lead to improved health outcomes? (2 points)
   1. The high proportion of the population with the condition that the test seeks to detect.
   2. The high sensitivity of the test in identifying the condition.
   3. A low frequency of false positive tests or a low frequency of adverse health outcomes from false positive results.
   4. The efficacy of treatment for persons who are screened as positive is not significant.

4. Which of the following statements describes the Kappa statistic? (2 points)
   1. A Kappa value of <0.40 represents excellent agreement.
   2. The Kappa statistic is a measure of agreement.
   3. The Kappa statistic is a measure of reliability.
   4. All of the above.
   5. Only B and C.

5. Positive predictive value is more influenced by the sensitivity than the specificity of the screening test. (1 point)
   1. True
   2. False
6. A “gold standard” is used to determine whether a screening test is
   1. cost-effective
   2. reliable
   3. valid
   4. none of the above

Please answer the 6 questions. Thank you.

Answer 1