Deck 9: Causality

Question 1

Why is a strong statistical association in a single study insufficient to show causal relations?

Answer 1

(Statements about causality require consideration of a number of factors, such as time sequence of events, biologic credibility, and dose-response relationships. Also, because a measured statistical association in a given study may be explained by chance, bias, or confounding, consistency with other investigations provides more convincing evidence to support claims about causality.)

Question 2

A valid statistical association in any analytic study design requires consideration of confounding. Which of the following best describes confounding?
A) When an extrinsic factor influences the disease outcome and may or may not influence the exposure

A) When the exposure variable influences the extrinsic factor, which then influences the disease outcome
B) When an extrinsic factor influences the disease outcome and, independent of that relationship, also influences the exposure
C) When an exposure and disease outcome are related

Answer 2

C

Question 3

Establishing a valid statistical association is a necessary part of establishing a cause-effect relationship.

Answer 3

True

Question 4

For each of the following statements, indicate whether the statistical association is likely due
-A case-control study showed that a strong negative association existed between exercise and heart disease.

A) chance
B) bias
C) confounding.

Question 5

For each of the following statements, indicate whether the statistical association is likely due
-A case-control study found a positive association between self-reported alcohol use during pregnancy and fetal alcohol syndrome.

A) chance
B) bias
C) confounding.

Question 6

For each of the following statements, indicate whether the statistical association is likely due
-A cohort study found no statistical association between smoking and coronary heart
Disease (RR = 1, p-value = 0.75).

A) chance
B) bias
C) confounding.

Question 7

For each of the following statements, indicate whether the statistical association is likely due
-The interviewer in a case-control study assumed that an association existed between alcohol consumption and myocardial infarction. She was aware of whether individuals in the study had myocardial infarction or not.

A) chance
B) bias
C) confounding.

Question 8

Match the following:
-___ A way to control for confounding

A) Blind
B) Increase sample size
C) Randomize

Question 9

Match the following:
-___ A way to control for bias

A) Blind
B) Increase sample size
C) Randomize

Question 10

Match the following:
-___ A way to control for a chance finding

A) Blind
B) Increase sample size
C) Randomize

Question 11

Precipitating factors are best defined as:

A) factors essential to the development of disease, conditions, injuries, disability, and death.
B) factors or conditions allowing or assisting the disease, condition, injury, disability, or death to begin and to be able to run its course of events.
C) factors or conditions already present that produce a susceptibility or disposition in a host to a disease or condition without actually causing it.
D) None of these is correct.

Question 12

Match the following:
-___ Method of difference

A) Increased numbers of children not immunized against measles cause the incidence rate for measles to go up.
B) Valley Fever (coccidioidomycosis) occurs only in the deserts of the southwestern United States.
C) Increasing trends in cigarette smoking are directly associated with increasing trends in lung cancer in many different places throughout the world.

Question 13

Match the following:
-___ Method of agreement

A) Increased numbers of children not immunized against measles cause the incidence rate for measles to go up.
B) Valley Fever (coccidioidomycosis) occurs only in the deserts of the southwestern United States.
C) Increasing trends in cigarette smoking are directly associated with increasing trends in lung cancer in many different places throughout the world.

Question 14

Match the following:
-___Method of concomitant variation

A) Increased numbers of children not immunized against measles cause the incidence rate for measles to go up.
B) Valley Fever (coccidioidomycosis) occurs only in the deserts of the southwestern United States.
C) Increasing trends in cigarette smoking are directly associated with increasing trends in lung cancer in many different places throughout the world.

Question 15

Among the causal criteria presented in the text, temporality was mentioned. Of the following study designs, which is best for establishing temporality?

A) Cross-sectional
B) Ecologic
C) Case-control
D) Experimental