NR 503 Population Health, Epidemiology &
Statistical Principles | Chamberlain
1. Which of the following describes the number of new cases of a disease in a population over
a specific period?
A. Prevalence
B. Incidence
C. Mortality
D. Morbidity
Answer: B
Rationale: Incidence specifically tracks the rate at which new events occur in a defined
population. This metric is essential for understanding the risk of contracting a disease
within a certain timeframe. Prevalence, by contrast, accounts for all existing cases
regardless of when they started.
2. A study compares individuals with a disease to those without the disease to look for past
exposures. What type of study is this?
A. Case-control study
B. Randomized controlled trial
C. Cohort study
,D. Cross-sectional study
Answer: A
Rationale: A case-control study is retrospective in nature and starts with the outcome to
look for causes. Researchers select ‘cases’ with the condition and ‘controls’ without it to
identify differences in exposure history. This design is particularly useful for studying rare
diseases or those with long latency periods.
3. Which statistical value represents the probability that the observed results occurred by
chance alone?
A. P-value
B. Standard deviation
C. Relative risk
D. Confidence interval
Answer: A
Rationale: The p-value is a measure used in hypothesis testing to determine the
significance of the results. A low p-value suggests that the null hypothesis should be
rejected because the findings are unlikely to be due to random chance. Typically, a value
below 0.05 is considered statistically significant in clinical research.
4. Sensitivity is defined as the ability of a diagnostic test to:
A. Correctly identify those who do not have the disease
, B. Predict the likelihood of a future disease occurrence
C. Correctly identify those who actually have the disease
D. Measure the severity of a specific illness
Answer: C
Rationale: Sensitivity measures the proportion of true positives among those who actually
have the condition. A highly sensitive test is useful for screening because it minimizes false
negatives. It ensures that most individuals with the disease are captured during the initial
testing phase.
5. What is the primary focus of the Belmont Report’s principle of ‘Justice’?
A. Obtaining informed consent from all research subjects
B. Maximizing benefits and minimizing risks to participants
C. Ensuring the benefits and burdens of research are distributed fairly
D. Protecting the autonomy of vulnerable populations
Answer: C
Rationale: The principle of Justice requires that the selection of research subjects be
equitable and fair. It prohibits targeting specific groups based on convenience or
vulnerability rather than scientific necessity. This principle ensures that no single group
bears an unfair burden of research risks.