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Flashcards in L5 concept of cause Deck (16):
1

define causation

single condition or event that invariably leads to particular outcome

2

what are the three conditions of cause?

1. must precede the effect
2. can involve host or environment
3. can be either positive or negative

3

what are the three components of cause?

1. component causes eg/ pieces of pie
2. necessary causes eg/ most important piece of pie
3. sufficient causes eg/ whole pie

4

component causes can occur far apart in time true or false?

true

5

describe the difference between direct and indirect cause

direct cause = no known intervening variable between exposure factor and disease
indirect cause = effect exposure meditated through one or more intervening variable

6

how do we determination causation, with statistics or judgment?

JUDGEMENT
statistics is only used for association studies

7

What are the three criteria for making judgement on causation?

- koch's postulates
- hills criteria
- evans criteria

8

should hills criteria be used rigidly?

no

9

list the 8 factors of criteria for causation via the hills method

1. specificity
2. strength of association
3. consistency
4. plausibility and coherence
5. temporality
6. analogy
7. dose response
8. experimental evidence

some silly characters plan to annihilate dogs everywhere

10

describe strength of association

strong associations more likely to be causal because they are unlikely to be due entirely to bias and confounding
A WEAK ASSOCIATION DOES NOT ELIMINATE CAUSATION

11

describe consistency

has the cause and effect relationship been identified by a number of different researchers?

12

describe specificity

a single exposure should cause a single disease
- many exceptions e.g./ smoking associated w/ many diseases not just lung cancer

13

describe temporality

cause must PRECEDE the effect
- prospective studies less likely to confuse the issue of temporarlity

14

describe dose response relationship

level of exposure increased, rate of disease should increase

15

describe plausibility and coherence

causal interpretation should fit with known facts of nature, history, and biology of disease.
needs to make biological sense

16

describe experimental evidence

can we reproduce outcome - exposure in experiment
often can't because of ethical/ welfare reasons.