Models of causality I

Question 1

Deterministic model

Answer 1

C —> D

• Specificity of the cause
• Specificity of the disease
• C is a sufficient and necessary cause for D

Question 2

Koch’s postulates (deterministic model)

Answer 2

• The organism is always found in people with the disease (necessary cause).

• The organism is not found with any other disease (specificity of the effect).

• The organism, when isolated from one who has the disease, and cultured through several generations, produces the disease (in experimental animals) (sufficient cause), and only one microorganism is isolated in a pure culture (specific cause).

-> Not perfect but very useful for infectious diseases.
-> Does no longer apply

Question 3

Multicausal model

Answer 3

It originates from the fact that we live in an ecological system where there is a complex relationship between factors intrinsic to the individual and extrinsic factors.

Question 4

Intrinsic factors

Answer 4

Genoma
Specific immunity
Personality

Question 5

Extrinsic factors

Answer 5

Biological
Social
Chemical
Physical

Question 6

Types of causal relationships in multicausal model

Answer 6

Conjunctive plurality of causes
Disjunctive plurality of causes

(In both cases, each cause can lead to multiple outcomes)

Question 7

Conjunctive plurality of causes

Answer 7

Each factor is necessary, but not sufficient

Question 8

Disjunctive plurality of causes

Answer 8

Each factor is sufficient, but not necessary

Question 9

Rothman’s model allows to

Answer 9

Explain certain epidemiological phenomena:
- Strength of the association
- Interaction
- Proportion of a disease that can be attributed to a given exposure
- Induction period

Question 10

Rothman’s modified deterministic model

Answer 10

(Presentación)