Establishment and use of reference values

Question 1

1. A “subject-based” reference value is:

a. obtained from a group of systematically defined reference individuals.
b. the type of value referred to when the term reference
value is used with no qualifying words.
c. based on several samples collected over time in a single
individual.
d. a random sample of all individuals in the parent population who fulfill the selection criteria.

Answer 1

c. based on several samples collected over time in a single
individual.

Question 2

2. True-negatives ÷ (false-positives + true-negatives) × 100 is
   the formula for determining:
   a. clinical sensitivity.
   b. clinical specificity.
   c. predictive value.
   d. reference value

Answer 2

b. clinical specificity.

Question 3

3. The proportion of a population that has the particular disease being studied for establishment of reference values is
   referred to as the:
   a. prevalence.
   b. predictive value.
   c. positive value.
   d. clinical sensitivity.

Answer 3

a. prevalence.

Question 4

4. When reference values are established, the criteria used
   to determine which individuals should be included in the
   group of reference individuals are referred to as:
   a. exclusion criteria.
   b. inclusion criteria.
   c. partition criteria.
   d. selection criteria.

Answer 4

d. selection criteria.

Question 5

5. Calculate the predictive value of a test in which 220 tested
   individuals with positive test results actually have the disease and 45 tested individuals with positive test results do
   not have the disease.
   a. 16.9%
   b. 66%
   c. 83%
   d. 120%

Answer 5

c. 83%

Question 6

6. An example of an exclusion criterion when establishing
   reference values would be a(n):
   a. individual’s age.
   b. risk factor such as obesity.
   c. individual’s ethnic origin.
   d. individual’s sex.

Answer 6

b. risk factor such as obesity.

Question 7

7. In the selection of reference individuals, subclassifying
   a set of these individuals into homogeneous groups is referred to as:
   a. partitioning.
   b. excluding.
   c. transferring.
   d. including.

Answer 7

a. partitioning.

Question 8

8. The number of true positive results divided by the sum of
   true positive results plus false positive results is referred to
   as:
   a. clinical sensitivity of a positive result.
   b. clinical specificity of a positive result.
   c. prevalence of the disease.
   d. predictive value of a positive result.

Answer 8

d. predictive value of a positive result.

Question 9

9. When reference limits are determined, the statistical
   method that assumes that the true distribution of reference values is a Gaussian (normal) distribution is the:
   a. nonparametric method.
   b. parametric method.
   c. interpercentile interval method.
   d. predictive value.

Answer 9

b. parametric method.