1.Confounding is described as a:

a.Systematic difference in soliciting, recording, or interpreting information

b.Systematic difference between the groups being compared that distorts the true association between a cause and an effect

c.Systematic similarity between the groups being compared that distorts the true association between an exposure and disease

d.None of the above

2.Concerning confounding:

a.It results in mixing of effects between exposure and disease

b.Occurs when cases and controls have different characteristics

c.It is an inherent characteristic of the population

d.All of the above

3.Relating Confounding to the Counterfactual Ideal:

a.Confounding occurs when the risk of disease in the unexposed group does not equal the risk of disease the exposed group had they been unexposed.

b.Confounding can be thought of as a failure to come close to the counterfactual ideal

c.A & B are correct

d.None of the above is correct

4.A confounding variable must meet the following criteria, EXCEPT:

a.The confounder is a risk factor for disease among people who are unexposed.

b.The confounder occurs more or less often among the exposed than the unexposed

c.The confounder is an intermediate on the causal pathway between exposure and disease

d.A and C

5.In the study analysis phase, researchers can control or adjust for confounders by:

a.Randomization

b.Restriction

c.Standardization

d.All of the above

6.Which of the following statements is about randomization is incorrect?

a.Limited to case control studies

b.Randomly allocate study subjects to treatment groups so each subject has an equal chance of being assigned to the treatment or comparison group

c.This only works when study sample is large enough

d.This only works when treatment assignment is not influenced by investigator

7.The sensitivity of a test:

a.is the probability that a test correctly classifies individuals without preclinical disease as negative.

b.is the probability that a test correctly classifies positive individuals who have a preclinical disease.

c.is the proportion of individuals with a positive test who have preclinical disease

d.the proportion of individuals without the pre-clinical disease who test negative