1. Question: Suppose that an experimental study investigator randomized 100 men to the treatment
group and 100 men to the comparison group. However, only 75 men in the treatment group and
85 men in the comparison group were able to comply exactly with their assigned regimens.
Should the data analysis be based on the 200 men originally randomized or the 160 men who
were able to comply? Choose the best answer.
2. Question: What type of observational study design is best suited to study a disease that has a
long latent and induction period?
3. Question: Length bias occurs because fast growing tumors are more likely to be picked up by a
screening test than are slow growing tumors.
4. Question: Cigarette smoking is a of lung cancer.
5. Question: A cohort study of coffee drinking and anxiety was conducted at a university campus.
There were a total of 30,000 freshmen who participated. 10,000 were coffee drinkers and 20,000
were not. Of the coffee drinkers, 500 developed anxiety during the 4 year follow-up period. Of
the non-coffee drinkers, 200 developed anxiety during the same time period. Assume that no one
in the population died or was lost during the follow-up period. Calculate the risk ratio (a.k.a.
relative risk) using the given data. The numeric value of the risk ratio is…
6. Question: Adherence to which ethical principle helps determine whether the burdens and
benefits of research are distributed fairly?
7. Question: Which measure of association is commonly used by public health officials to
determine which exposures are most important to the entire population and helps prioritize
prevention activities?
8. Question: Which type of measure of disease frequency best describes the following: the
percentage of healthy, at-risk children in a daycare who develop impetigo (a skin disease) during
March 2012.
9. Question: What would happen to the predictive value positive if a screening test were
administered in a population with a disease prevalence of 1% instead of 30%? (Assume that the
sensitivity and specificity of the test remain the same.)
10. Question: What is the main limitation of a case series?
11. Question: Suppose that your company has just developed a new screening test for a disease and
you are in charge of testing its validity and feasibility. You decide to evaluate the test on 1000
individuals and compare the results of the new test to the gold standard. You know the prevalence
of disease in your population is 30%. The screening test gave a positive result for 292 individuals.
285 of these individuals actually had the disease on the basis of the gold standard determination.
Calculate the sensitivity of the new screening test:
12. Question: The main limitation of which type of study design is that researchers cannot infer the
temporal sequence between exposure and disease when the exposure is a changeable
characteristic?
13. Question: A case-control study was conducted to identify risk factors for the common cold.
Living with children under the age of 10 was one of the risk factors evaluated. The odds ratio for
this association was 9.0 and the 95% confidence interval ranged from 1.2 to 85. Which of the
following statements is true about this association?
14. Question: The purpose of a control group in a case-control study is to provide an estimate of the
exposure distribution in the source population that produced the cases.
15. Question: Which measure of disease frequency best describes the following:
16. Question: Non-compliance in an experimental study biases the results towards the null.
17. Question: A study followed 900,000 US adults from 1992 to 2008. At baseline, all participants
were screened and determined to be cancer free and their body mass index (BMI) was calculated.
Body mass index is a measure of obesity that is calculated using a person’s height and weight.
Subjects were separated into the following groups according to their BMI: (a) normal weight, (b)
slightly overweight, (c) moderately overweight and (d) greatly overweight. 57,145 deaths from
cancer occurred in the population during the follow-up period. Calculate the cumulative incidence
group and 100 men to the comparison group. However, only 75 men in the treatment group and
85 men in the comparison group were able to comply exactly with their assigned regimens.
Should the data analysis be based on the 200 men originally randomized or the 160 men who
were able to comply? Choose the best answer.
2. Question: What type of observational study design is best suited to study a disease that has a
long latent and induction period?
3. Question: Length bias occurs because fast growing tumors are more likely to be picked up by a
screening test than are slow growing tumors.
4. Question: Cigarette smoking is a of lung cancer.
5. Question: A cohort study of coffee drinking and anxiety was conducted at a university campus.
There were a total of 30,000 freshmen who participated. 10,000 were coffee drinkers and 20,000
were not. Of the coffee drinkers, 500 developed anxiety during the 4 year follow-up period. Of
the non-coffee drinkers, 200 developed anxiety during the same time period. Assume that no one
in the population died or was lost during the follow-up period. Calculate the risk ratio (a.k.a.
relative risk) using the given data. The numeric value of the risk ratio is…
6. Question: Adherence to which ethical principle helps determine whether the burdens and
benefits of research are distributed fairly?
7. Question: Which measure of association is commonly used by public health officials to
determine which exposures are most important to the entire population and helps prioritize
prevention activities?
8. Question: Which type of measure of disease frequency best describes the following: the
percentage of healthy, at-risk children in a daycare who develop impetigo (a skin disease) during
March 2012.
9. Question: What would happen to the predictive value positive if a screening test were
administered in a population with a disease prevalence of 1% instead of 30%? (Assume that the
sensitivity and specificity of the test remain the same.)
10. Question: What is the main limitation of a case series?
11. Question: Suppose that your company has just developed a new screening test for a disease and
you are in charge of testing its validity and feasibility. You decide to evaluate the test on 1000
individuals and compare the results of the new test to the gold standard. You know the prevalence
of disease in your population is 30%. The screening test gave a positive result for 292 individuals.
285 of these individuals actually had the disease on the basis of the gold standard determination.
Calculate the sensitivity of the new screening test:
12. Question: The main limitation of which type of study design is that researchers cannot infer the
temporal sequence between exposure and disease when the exposure is a changeable
characteristic?
13. Question: A case-control study was conducted to identify risk factors for the common cold.
Living with children under the age of 10 was one of the risk factors evaluated. The odds ratio for
this association was 9.0 and the 95% confidence interval ranged from 1.2 to 85. Which of the
following statements is true about this association?
14. Question: The purpose of a control group in a case-control study is to provide an estimate of the
exposure distribution in the source population that produced the cases.
15. Question: Which measure of disease frequency best describes the following:
16. Question: Non-compliance in an experimental study biases the results towards the null.
17. Question: A study followed 900,000 US adults from 1992 to 2008. At baseline, all participants
were screened and determined to be cancer free and their body mass index (BMI) was calculated.
Body mass index is a measure of obesity that is calculated using a person’s height and weight.
Subjects were separated into the following groups according to their BMI: (a) normal weight, (b)
slightly overweight, (c) moderately overweight and (d) greatly overweight. 57,145 deaths from
cancer occurred in the population during the follow-up period. Calculate the cumulative incidence
