NR503 Exam 4 Actual Exam Style V3 | NR
503 Population Health, Epidemiology &
Statistical Principles | Chamberlain
1. An epidemiologist is studying a rare neurological disorder. Which study design is most
efficient for investigating rare diseases when the outcome is already known?
A. Cohort Study
B. Randomized Controlled Trial
C. Cross-sectional Study
D. Case-Control Study
Correct Answer: D
Expert Explanation: A case-control study is highly efficient for researching rare conditions
because it starts with individuals who already have the outcome. By comparing cases to
controls, researchers can retrospectively look for exposures that might have led to the
disease. This method is much faster and less expensive than tracking a cohort over a long
period to see if a rare disease develops.
2. In a diagnostic test evaluation, sensitivity is defined as the ability of the test to:
A. Correctly identify those without the disease.
B. Maximize the negative predictive value.
C. Minimize false positives.
,D. Correctly identify those with the disease.
Correct Answer: D
Expert Explanation: Sensitivity refers to the proportion of truly diseased individuals who
are correctly identified by the screening test. A test with high sensitivity is crucial for
catching as many cases as possible, even if it results in some false positives. Understanding
sensitivity helps providers determine how reliable a negative result is in ruling out a
condition.
3. Which level of prevention is focused on reducing the impact of a long-term disease or
injury through rehabilitation and support groups?
A. Primary Prevention
B. Tertiary Prevention
C. Secondary Prevention
D. Quaternary Prevention
Correct Answer: B
Expert Explanation: Tertiary prevention aims to manage and soften the impact of ongoing
illness or injury that has lasting effects. This include activities like cardiac rehabilitation or
support groups for chronic conditions. It is distinct from secondary prevention, which
focuses on early detection before symptoms become severe.
, 4. A researcher reports a p-value of 0.02 for a study comparing two antihypertensive drugs.
Assuming an alpha of 0.05, what should the researcher conclude?
A. The results are not statistically significant.
B. There is a 2% chance the null hypothesis is true.
C. The null hypothesis should be rejected.
D. The study has low statistical power.
Correct Answer: C
Expert Explanation: A p-value of 0.02 is less than the standard significance level of 0.05,
indicating that the observed difference is unlikely to have occurred by chance.
Consequently, the researcher rejects the null hypothesis in favor of the alternative
hypothesis. This finding suggests a statistically significant difference between the two
medications studied.
5. What is the ‘ecological fallacy’ in epidemiological research?
A. Assuming that individuals have the same characteristics as the group they belong to.
B. Failing to account for environmental factors in a clinical trial.
C. The bias introduced when participants drop out of a cohort study.
D. Incorrectly generalizing results from an animal study to a human population.
Correct Answer: A
503 Population Health, Epidemiology &
Statistical Principles | Chamberlain
1. An epidemiologist is studying a rare neurological disorder. Which study design is most
efficient for investigating rare diseases when the outcome is already known?
A. Cohort Study
B. Randomized Controlled Trial
C. Cross-sectional Study
D. Case-Control Study
Correct Answer: D
Expert Explanation: A case-control study is highly efficient for researching rare conditions
because it starts with individuals who already have the outcome. By comparing cases to
controls, researchers can retrospectively look for exposures that might have led to the
disease. This method is much faster and less expensive than tracking a cohort over a long
period to see if a rare disease develops.
2. In a diagnostic test evaluation, sensitivity is defined as the ability of the test to:
A. Correctly identify those without the disease.
B. Maximize the negative predictive value.
C. Minimize false positives.
,D. Correctly identify those with the disease.
Correct Answer: D
Expert Explanation: Sensitivity refers to the proportion of truly diseased individuals who
are correctly identified by the screening test. A test with high sensitivity is crucial for
catching as many cases as possible, even if it results in some false positives. Understanding
sensitivity helps providers determine how reliable a negative result is in ruling out a
condition.
3. Which level of prevention is focused on reducing the impact of a long-term disease or
injury through rehabilitation and support groups?
A. Primary Prevention
B. Tertiary Prevention
C. Secondary Prevention
D. Quaternary Prevention
Correct Answer: B
Expert Explanation: Tertiary prevention aims to manage and soften the impact of ongoing
illness or injury that has lasting effects. This include activities like cardiac rehabilitation or
support groups for chronic conditions. It is distinct from secondary prevention, which
focuses on early detection before symptoms become severe.
, 4. A researcher reports a p-value of 0.02 for a study comparing two antihypertensive drugs.
Assuming an alpha of 0.05, what should the researcher conclude?
A. The results are not statistically significant.
B. There is a 2% chance the null hypothesis is true.
C. The null hypothesis should be rejected.
D. The study has low statistical power.
Correct Answer: C
Expert Explanation: A p-value of 0.02 is less than the standard significance level of 0.05,
indicating that the observed difference is unlikely to have occurred by chance.
Consequently, the researcher rejects the null hypothesis in favor of the alternative
hypothesis. This finding suggests a statistically significant difference between the two
medications studied.
5. What is the ‘ecological fallacy’ in epidemiological research?
A. Assuming that individuals have the same characteristics as the group they belong to.
B. Failing to account for environmental factors in a clinical trial.
C. The bias introduced when participants drop out of a cohort study.
D. Incorrectly generalizing results from an animal study to a human population.
Correct Answer: A
