Lecture 4: What is epidemiology

Question 1

Give the definition of epidemiology:

Answer 1

the study of the distribution and determinants of health-related states or events in specific populations

Question 2

Fill in the gaps: communicable diseases are s_________ and d___________ in the way they cause ill health

Answer 2

singular, deterministic

Question 3

Fill in the gaps: chronic diseases are m____________ and p____________ in their aetiology

Answer 3

multifactorial, probabilistic

Question 4

What is the purpose of the Bradford-Hill Viewpoints?

Answer 4

it acts as a framework used to assess whether an observed association is likely to be causal

Question 5

Describe how the ‘strength of association’ point of the Bradford-Hill Viewpoints is used to assess causality:

Answer 5

the stronger the association, the more likely the relationship is to be causal

Question 6

Describe how the ‘consistency of findings’ point of the Bradford-Hill Viewpoints is used to assess causality:

Answer 6

check whether the same findings have been observed among different populations at different times - this indicates causality

Question 7

Describe how the ‘specificity of association’ point of the Bradford-Hill Viewpoints is used to assess causality:

Answer 7

there must be a one to one relationship between cause and outcome

Question 8

Describe how the ‘temporal sequence’ point of the Bradford-Hill Viewpoints is used to assess causality:

Answer 8

the exposure must precede outcome

Question 9

Describe how the ‘dose response’ point of the Bradford-Hill Viewpoints is used to assess causality:

Answer 9

change in disease rates should follow from corresponding changes in exposure

Question 10

Describe how the ‘biological plausibility ‘ point of the Bradford-Hill Viewpoints is used to assess causality:

Answer 10

there should be a the presence of a potential biological mechanism behind the association

Question 11

Describe how the ‘coherence’ point of the Bradford-Hill Viewpoints is used to assess causality:

Answer 11

does the relationship agree with the current knowledge of the natural history of the disease? - if yes, this supports causality

Question 12

Describe how the ‘experiment’ point of the Bradford-Hill Viewpoints is used to assess causality:

Answer 12

does the removal of the exposure alter the frequency of the outcome? - if yes, this supports causality

Question 13

Describe how the ‘analogy’ point of the Bradford-Hill Viewpoints is used to assess causality:

Answer 13

are there similarities between the observed association and any other associations? -if yes, this supports causality

Question 14

What does the Prevention Paradox state?

Answer 14

a smaller risk affecting many people produces more cases than a larger risk affecting a few

Question 15

Give the definition of attributable risk:

Answer 15

a measure of the proportion of morbidity or mortality that can be attributed to a given exposure

Question 16

Give the equation for attributable risk (incidence):

Answer 16

total incidence - incidence (Non- Exposed)

Question 17

What is ‘background risk’?

Answer 17

The incidence not attributable to exposure

Question 18

What is ‘potential for prevention’?

Answer 18

takes attributable risk and states the counterfactual version

Question 19

Describe the link between factual and counterfactual:

Answer 19

the current situation versus the situation you’re hoping realise (the current level of exposure versus the ideal level of exposure)

Question 20

Give the two contexts that attributable risk can be used in?

Answer 20

1) dealing with individuals (clinical context)

2) dealing with populations (public health context)