Causality

Question 1

What is selection bias?

Answer 1

This is when our group which we are testing are not representative of the population and so any comparison made is not like with like.

Question 2

What is reverse causality?

Answer 2

Reverse causality is where if we are testing to see if X causes Y, then the truth is that Y causes X.

Question 3

If we observe an association between X and Y, it can be due to:

Answer 3

An unknown confounding factor
Common cause
Reverse causality
A true causal association

Question 4

According to Koch Postulates, what are the three cause-effect relationships?

Answer 4

Necessary - the agent is present in all cases of disease
Sufficient - the agent can produce disease in animal testing
Specific - the agent is not found in any other diseases.

Question 5

What are the 9 Bradford Hill Criteria?

Answer 5

Strength of Association, Specificity of association, consistency of association, temporal sequence, dose response, reversibility, coherence of theory, biological plausibility, analogy.