CORRECT ANSWERS
Which of the following conclusions to explain the hypothetical statement that "Air
pollution is higher in New York City than in Washington D.C., but mortality from lung
disease is lower in New York City than in Washington D.C." would be an example of
ecologic fallacy?
A. people in NYC may have better health insurance than people in DC
B. NYC may provide better treatment for lung disease than DC
C. persons dying of lung disease in DC may have moved from high air pollution cities
D. air pollution protects against lung disease deaths - Answer- D
Which of the following are advantages of ecologic studies?
A. individual-level data on exposure and health outcomes are often publicly available in
state and national data bases
B. useful for evaluating impact of community-level interventions
C. help conservationists understand ecological principles
D. convenience
E. low cost - Answer- C, D, E
Interpret the meaning of one study's reported odds ratio of 1.6 (95% CI 1.1, 3.4) for the
association between high level of fish oil consumption and prostate cancer. - Answer-
cases are statistically significantly more likely than controls to have a high level of
consumption of fish oil
Interpret the meaning of an odds ratio of 1.00 for the association between consumption
of fish oil and prostate cancer - Answer- there is no association between fish oil intake
and prostate cancer
True or false: both a prevalence ratio and a prevalence difference are considered
measures of occurrence. - Answer- false
True or false: both a risk ratio and a risk difference are considered measures of disease
occurrence. - Answer- false
True or false: The term "relative risk" is the most precise term to use when discussing
measures of association. - Answer- false
, True or false: The term "relative risk" is sometimes used to refer to any of the ratio
measures of association - Answer- true
Which of the following are ratio measures used in epidemiology?
A. odds ratio
B. risk ratio
C. rate ratio
D. prevalence ratio
E. occurrence ratio - Answer- A, B, C, D
True or false: It is best to use a difference measure when trying to understand the cause
or etiology of a health outcome or disease. - Answer- false
True or false: When a ratio measure is less than 1 it means the prevalence, risk or rate
in the exposed is greater than in the unexposed group. - Answer- false
True or false: When a ratio measure is greater than 1 it means the prevalence, risk or
rate in the exposed is greater than in the unexposed group. - Answer- true
What is true about a ratio measure that equals 1.0? - Answer- there is no association
between the exposure and the health outcome
What is true about a ratio measure is greater than 1.0? - Answer- there is possible
causal association between the exposure and the health outcome
What is true about a ratio measure that is less than 1.0? - Answer- there is possible
protective association between then exposure and the health outcome
True or false: A ratio measure of association expresses the prevalence, risk or rate
among exposed in excess of that among the unexposed or less-exposed. - Answer-
false
True or false: A difference measure treats the prevalence, risk or rate of the health
outcome among the unexposed group as a "background" prevalence, risk or rate. -
Answer- true
What is true about a difference measure that is less than 0? - Answer- there is possible
protective association between the exposure and the health outcome
True or false: The null value used when interpreting a difference measure is 0. -
Answer- true
Interpret the meaning of one study's reported rate ratio of 0.5 (95% CI 0.2, 0.9) for the
association between high level of Vitamin D consumption and breast cancer incidence. -
Answer- those who consume a high level of vitamin D are statistically significantly less