NR503 Final Exam Actual Exam Style V3 |
NR 503 Population Health, Epidemiology
& Statistical Principles | Chamberlain
1. A provider is evaluating a new screening test for Type 2 Diabetes. The test correctly
identifies 90% of individuals who actually have the disease. This specific metric represents
which of the following?
A. Specificity
B. Positive Predictive Value
C. Sensitivity
D. Negative Predictive Value
Correct Answer: C
Expert Explanation: Sensitivity is defined as the ability of a test to correctly identify those
with the disease, also known as the true positive rate. In this scenario, the 90% figure
refers specifically to the proportion of diseased individuals who tested positive. High
sensitivity is crucial for screening tests to ensure that as few cases as possible are missed.
2. When conducting a study to determine if a specific environmental toxin is associated with
a rare form of leukemia, which study design is most efficient and cost-effective?
A. Case-Control Study
B. Prospective Cohort Study
C. Randomized Controlled Trial
,D. Retrospective Cohort Study
Correct Answer: A
Expert Explanation: Case-control studies are the preferred design when investigating rare
diseases because they begin by identifying individuals who already have the outcome. This
approach allows researchers to look back at exposures without waiting for new cases to
develop over many years. It is significantly more cost-effective and time-efficient than
following a large cohort until a sufficient number of rare events occur.
3. An epidemiologist reports that the incidence of influenza in a specific county has doubled
over the last month, while the prevalence has remained relatively stable. Which of the
following best explains this phenomenon?
A. The duration of the disease is very short due to rapid recovery or death.
B. The duration of the disease has increased.
C. The population size has decreased significantly.
D. The test used for diagnosis has become less sensitive.
Correct Answer: A
Expert Explanation: Prevalence is a product of incidence and the average duration of the
disease. If incidence increases but prevalence stays the same, it implies that people are
leaving the ‘prevalent’ pool as quickly as they are entering it. This typically occurs in
diseases with a very short duration, such as acute infections where patients either recover
quickly or die shortly after onset.
,4. A research study yields a p-value of 0.02. If the alpha level was set at 0.05, what is the most
appropriate conclusion regarding the null hypothesis?
A. Fail to reject the null hypothesis.
B. Accept the null hypothesis as true.
C. Reject the null hypothesis.
D. The results are clinically significant but not statistically significant.
Correct Answer: C
Expert Explanation: In statistical hypothesis testing, if the p-value is less than the
predetermined alpha level, the result is considered statistically significant. Because 0.02 is
less than 0.05, the researcher should reject the null hypothesis in favor of the alternative
hypothesis. This indicates that the observed effect is unlikely to have occurred by chance
alone under the assumption that the null hypothesis is true.
5. The ‘Social Determinants of Health’ refer to which of the following factors?
A. Individual genetic predispositions and biological markers.
B. The conditions in which people are born, grow, live, work, and age.
C. Only the availability of high-technology medical equipment in hospitals.
D. The specific surgical techniques used to treat chronic illnesses.
Correct Answer: B
, Expert Explanation: Social determinants of health (SDOH) encompass the non-medical
factors that influence health outcomes, such as socioeconomic status, education, and
physical environment. These factors are shaped by the distribution of money, power, and
resources at global, national, and local levels. Understanding SDOH is essential for
population health as these factors often have a greater impact on health outcomes than
healthcare delivery itself.
6. A public health nurse is reviewing a report that describes the ‘Attack Rate’ of a foodborne
illness at a local picnic. What does the Attack Rate represent?
A. The total number of deaths divided by the total population.
B. The number of new cases per person-year of observation.
C. The proportion of people who became ill after being exposed to the source.
D. The percentage of the population that is immune to the pathogen.
Correct Answer: C
Expert Explanation: An attack rate is a specific type of incidence rate used during short-
term outbreaks, usually expressed as a percentage. it compares the number of people who
became ill to the total number of people who were exposed to the specific risk factor. This
metric helps investigators pinpoint the source of an outbreak, such as a contaminated food
item at a specific event.
NR 503 Population Health, Epidemiology
& Statistical Principles | Chamberlain
1. A provider is evaluating a new screening test for Type 2 Diabetes. The test correctly
identifies 90% of individuals who actually have the disease. This specific metric represents
which of the following?
A. Specificity
B. Positive Predictive Value
C. Sensitivity
D. Negative Predictive Value
Correct Answer: C
Expert Explanation: Sensitivity is defined as the ability of a test to correctly identify those
with the disease, also known as the true positive rate. In this scenario, the 90% figure
refers specifically to the proportion of diseased individuals who tested positive. High
sensitivity is crucial for screening tests to ensure that as few cases as possible are missed.
2. When conducting a study to determine if a specific environmental toxin is associated with
a rare form of leukemia, which study design is most efficient and cost-effective?
A. Case-Control Study
B. Prospective Cohort Study
C. Randomized Controlled Trial
,D. Retrospective Cohort Study
Correct Answer: A
Expert Explanation: Case-control studies are the preferred design when investigating rare
diseases because they begin by identifying individuals who already have the outcome. This
approach allows researchers to look back at exposures without waiting for new cases to
develop over many years. It is significantly more cost-effective and time-efficient than
following a large cohort until a sufficient number of rare events occur.
3. An epidemiologist reports that the incidence of influenza in a specific county has doubled
over the last month, while the prevalence has remained relatively stable. Which of the
following best explains this phenomenon?
A. The duration of the disease is very short due to rapid recovery or death.
B. The duration of the disease has increased.
C. The population size has decreased significantly.
D. The test used for diagnosis has become less sensitive.
Correct Answer: A
Expert Explanation: Prevalence is a product of incidence and the average duration of the
disease. If incidence increases but prevalence stays the same, it implies that people are
leaving the ‘prevalent’ pool as quickly as they are entering it. This typically occurs in
diseases with a very short duration, such as acute infections where patients either recover
quickly or die shortly after onset.
,4. A research study yields a p-value of 0.02. If the alpha level was set at 0.05, what is the most
appropriate conclusion regarding the null hypothesis?
A. Fail to reject the null hypothesis.
B. Accept the null hypothesis as true.
C. Reject the null hypothesis.
D. The results are clinically significant but not statistically significant.
Correct Answer: C
Expert Explanation: In statistical hypothesis testing, if the p-value is less than the
predetermined alpha level, the result is considered statistically significant. Because 0.02 is
less than 0.05, the researcher should reject the null hypothesis in favor of the alternative
hypothesis. This indicates that the observed effect is unlikely to have occurred by chance
alone under the assumption that the null hypothesis is true.
5. The ‘Social Determinants of Health’ refer to which of the following factors?
A. Individual genetic predispositions and biological markers.
B. The conditions in which people are born, grow, live, work, and age.
C. Only the availability of high-technology medical equipment in hospitals.
D. The specific surgical techniques used to treat chronic illnesses.
Correct Answer: B
, Expert Explanation: Social determinants of health (SDOH) encompass the non-medical
factors that influence health outcomes, such as socioeconomic status, education, and
physical environment. These factors are shaped by the distribution of money, power, and
resources at global, national, and local levels. Understanding SDOH is essential for
population health as these factors often have a greater impact on health outcomes than
healthcare delivery itself.
6. A public health nurse is reviewing a report that describes the ‘Attack Rate’ of a foodborne
illness at a local picnic. What does the Attack Rate represent?
A. The total number of deaths divided by the total population.
B. The number of new cases per person-year of observation.
C. The proportion of people who became ill after being exposed to the source.
D. The percentage of the population that is immune to the pathogen.
Correct Answer: C
Expert Explanation: An attack rate is a specific type of incidence rate used during short-
term outbreaks, usually expressed as a percentage. it compares the number of people who
became ill to the total number of people who were exposed to the specific risk factor. This
metric helps investigators pinpoint the source of an outbreak, such as a contaminated food
item at a specific event.
