Association & Causation (10) - End E2

Question 1

What is more objective?

Answer 1

scientific inquiry

Question 2

What is the terminology of analytic epidemiology?

Answer 2

variable

Question 3

Variables are either _____ or they are not. If not, they are said to be ______

Answer 3

independent or dependent

not: independent

Question 4

In associations, X and Y are dependent. What are the types?

Answer 4

non-casually (x does not cause y)

casually (x causes y)

Question 5

What is an independent variable?

Answer 5

a factor that stands alone and isn’t changed by the other factor you are trying to measure
- species, breed, sex, age

Question 6

What is a dependent variable?

Answer 6

a factor that is influenced or changed by another factor

Question 7

What is a confounding variable?

Answer 7

interference by a third factor that distorts the association within a study of two primary variables

Question 8

In an scatter plot, the closer the points lie with respect to the straight line of best fit through them, the [stronger/weaker] the association between variables X and Y

Answer 8

stronger

Question 9

What is a dose-response curve?

Answer 9

type of correlative association between an exposure and an effect

Question 10

What is threshold in a dose-response curve?

Answer 10

refers to the lowest dose at which a particular response occurs

Question 11

What is an epidemic curve?

Answer 11

a graph plotting the distribution of cases by time of onset

Question 12

What is a contingency table?

Answer 12

tabular method of demonstrating association
data are tabulated in two dimensions

Question 13

What is causality in epidemiologic studies?

Answer 13

one of the central concerns of epidemiology - to be able to assert that a causal association exists between an exposure factor and a disease

causality is a very complex issue

Question 14

What is USPHS causality criteria?

Answer 14

Question 15

What is consistency?

Answer 15

the association has been observed repeatedly, ideally by different observers

Question 16

What is the strength of association?

Answer 16

refers to the magnitude of relative risk or odds ratios from observed studies

Question 17

A [positive/negative] dose-response gradient is another attribute of a causal association

Answer 17

positive

Question 18

What is specificity?

Answer 18

one particular exposure produces one specific outcome (or disease)

• if the biological response to an exposure is variable, it is less likely to be causal

Question 19

What is temporality?

Answer 19

the exposure or factor must precede the outcome or disease

Question 20

What is coherence?

Answer 20

the cause-and-effect interpretation of the data should not seriously conflict with the generally known facts of the natural history and biology of the disease

synonymous with “biological plausibility”

Question 21

What is multifactorial (multiple) causality?

Answer 21

many types of causal relationships involve diseases with more than one causal factor

two models:
epidemiologic triangle
web of causation

Question 22

What are the 2 models of multifactorial causality?

Answer 22

epidemiologic triangle
web of causation

Question 23

What is an agent?

Answer 23

a factor — such as a microorganism, chemical substance, or form of radiation— whose presence, excessive presence, or (in deficiency disease) relative absence is essential for the occurrence of a disease

Question 24

What is host?

Answer 24

person or other living animal, including birds and arthropods, that affords subsistence or lodgment to an infectious agent under natural conditions

Question 25

What is an environment?

Answer 25

the domain in which disease-causing agents may exist, survive, or originate

Question 26

What is a web of causation?

Answer 26

Question 27

How do we rule out chance?

Answer 27

epidemiologists employ statistical procedures to assess the degree to which chance may have accounted for observed associations

we never completely rule out chance!

Question 28

What are methods for minimizing chance?

Answer 28

work through the causality criteria
minimize bias and confounding

Question 29

What is a risk factor?

Answer 29

na exposure that is associated with a disease, morbidity, mortality, or adverse health outcome

Question 30

What is risk assessment?

Answer 30

methodology used to provide quantitative measurement of risk to health

Question 31

What is probability vs chance?

Answer 31

probability: chance or risk of an event occurring (a proportion)

odds: ratio of the probability of an event occurring to the probability of an event not occurring

Question 32

Probability varies from ___ and ____. Odd varies between ____ and ____

Answer 32

probability: 0 and 1
odds: 0 and infinity