Interpretation of Epidemiological Findings Pt.1

Question 1

List the Bradford Hill criteria.

Answer 1

strength
consistency
specificity
temporality
biological gradient
plausibility
coherence
experiment
analogy

Question 2

What is ‘strength’?

Answer 2

strong association > increases confidence that exposure causes outcome

Question 3

What is ‘specificity’?

Answer 3

describes association between specific causes and specific effects

Question 4

What is ‘temporality’?

Answer 4

insufficient for exposure A and outcome B to coexist > A must precede B

Question 5

What is ‘biological gradient’?

Answer 5

dose response effect 9in the ‘right’ direction is a compelling argument for causality

Question 6

What is ‘coherence’?

Answer 6

association ought to be consistent with existing theory and knowledge

Question 7

What is ‘analogy’?

Answer 7

based off analogous findings, you can make inferences on the relationship

Question 8

Define internal validity.

Answer 8

extent to which findings accurately describe the relationship between exposure and outcome in the context of the study

Question 9

External validity is synonymous with?

Answer 9

Generalisability

Question 10

Define bias.

Answer 10

any trend in the collection, analysis. interpretation, publication or review of data that can lead to conclusions that are systematically different from the truth

Question 11

Name 3 types of bias.

Answer 11

selection bias
information bias
confounding

Question 12

What is selection bias?

Answer 12

when a patient’s chance of being selected for a study is related to the exposure or outcome

Question 13

List types of selection bias.

Answer 13

Berkson’s bias

healthy worker effect

Question 14

What is Berkson’s bias?

Answer 14

in a hospital based case control study and controls are selected from hospital patients

Question 15

How to minimise selection bias?

Answer 15

make sure controls are representative of the target population, minimise non response, compare respondents and non respondents

Question 16

List types of information bias.

Answer 16

misinformation
misclassification
interviewer bias
recall bias

Question 17

Non-differential misclassification always results in?

Answer 17

bias towards to null

Question 18

Differential misclassification can result in?

Answer 18

bias towards or away from the null

Question 19

What is information bias?

Answer 19

misclassification of the exposure, outcome or both

Question 20

Define external validity.

Answer 20

extent to which results of a study can be generalised to and across other situations, people, stimuli, times