Causation and Causal Inference

Question 1

● Without it an outcome will not be observed even if other conditions are satisfied

Answer 1

NECESSARY CAUSE

Question 2

● A malnourished individual will not develop TB if the individual has not acquired the mycobacterium tuberculosis bacteria

Answer 2

NECESSARY CAUSE

Question 3

“consists of several components that interact to promote the occurrence of the outcome”

Answer 3

SUFFICIENT CAUSE

Question 4

•The causes other than necessary cause, complementing or helping the necessary cause are considered as

Answer 4

components of the cause.

Question 5

Epidemiologic Triad

Answer 5

Host, Agent, Environment

Question 6

This model implies that an interplay of these factors must be analyzed and understood for comprehension and predictions of patterns of disease

Answer 6

Epidemiologic Triangle

Question 7

In this model the host and agent are at opposite ends of a hypothetical lever for which the environment serves as the fulcrum

Answer 7

Epidemiologic Lever

Question 8

The hub or center of the wheel represents the host and the surrounding is the biological, social and physical environment

Answer 8

The Wheel

Question 9

Effects are not due to single isolated causes but develop as a result of chain of causation in which each link can be linked to another

Answer 9

The Web of Causation

Question 10

A process of proving that a particular hypothesis is a real one and causal

Answer 10

Causal Inference

Question 11

A small association does not mean that there is not a causal effect

Answer 11

Strength

Question 12

Consistent findings observed by different persons in different places with different samples strengthens the likelihood of an effect

Answer 12

Consistency

Question 13

Causation is likely if a very specific population at a specific site and disease with no other likely explanation.
-The more specific an association between a factor and an effect is, the bigger the probability of a causal relationship.

Answer 13

Specificity:

Question 14

The effect has to occur after the cause (and if there is an expected delay between the cause and expected effect, then the effect must occur after that delay).

Answer 14

Temporality

Question 15

Greater exposure should generally lead to greater incidence of the effect.
• However, in some cases, the mere presence of the factor can trigger the effect.

Answer 15

Biological gradient:

Question 16

Coherence between epidemiological and laboratory findings increases the likelihood of an effect.
• However, Hill noted that “… lack of such [laboratory] evidence cannot nullify the epidemiological affect on associations”

Answer 16

Coherence

Question 17

removal of the possible cause lead to reduction of the disease risk

Answer 17

Reversibility