epidemiology questions

1.      A study is said to have internal validity when:

A. there have been proper selection of study groups

B.  a lack of error in measurement.

C. There is ability to generalize beyond a set of observations to some universal statement.

D. A and B

2.      A test that determines whether disease is actually present is a:

                        A.        screening test

                        B.        diagnostic test

                        C.        reliability test

                        D.        none of the above

3.      Sensitivity refers to the ability of a screening test to correctly identify all screened individuals who have a disease.

A.    True

B.     False

4.      The ability of a measuring instrument to give consistent results on repeated trials refers to:

A.    Accuracy

B.     Reliability

C.     Sensitivity

D.    Specificity

Use the information below to answer questions 5 to 10

5.      Calculate the sensitivity of the test:

6.      Calculate the specificity of the test:

7.      What is the positive predictive value?

8.      What is the negative predictive value?

9.      What is the accuracy of the screening test?

10.  What is the prevalence?

Reference book: R. Frriis, “Epidemiology for Public Health Practice (2009)