Epidemiology & Biostatistics Nursing Exam | 2026/2027
EPIDEMIOLOGY & BIOSTATISTICS NURSING EXAM
Data Interpretation | 2026/2027 Edition
60 Questions with Correct Answers and Rationales
Domain Questions Points
Study Design & Research Methodology 1–6
Measures of Disease Frequency 7–12
Risk Assessment (RR, OR, AR) 13–18
Statistical Inference & Hypothesis Testing 19–24
Data Interpretation & Graphical Analysis 25–30
Screening Test Validity (Sensitivity, Specificity, PPV/NPV) 31–36
Outbreak Investigation Principles 37–42
Evidence-Based Practice Application 43–48
Health Disparities & Population Health Metrics 49–54
Ethical Considerations in Epidemiologic Research 55–60
TOTAL 1–60 60
Instructions
• This examination consists of 60 multiple-choice questions covering 10 epidemiology and biostatistics domains.
• Select the single best answer for each question. Each correct answer is worth 1 point (Total: 60 points).
• Correct answers are displayed in bold cyan with a detailed rationale explaining epidemiologic and statistical
reasoning.
• All questions are aligned with CDC/WHO public health frameworks, AACN Essentials, and NCSBN competency
standards.
• Calculations and interpretive reasoning are emphasized; basic statistical formulas may be required.
Name: Date: ________________________ Score: _______ / 60
________________________
Domain 1: Study Design & Research Methodology
1
, Epidemiology & Biostatistics Nursing Exam | 2026/2027
1. Which study design provides the strongest evidence for establishing a cause-and-effect relationship between an
exposure and a disease?
A. Cross-sectional study
B. Case-control study
C. Randomized controlled trial
D. Ecological study
Correct Answer: C. Randomized controlled trial
Rationale: Randomized controlled trials (RCTs) are considered the gold standard for establishing causality because
randomization minimizes confounding and selection bias, allowing a direct comparison between intervention and
control groups.
2. A researcher conducts a study where a group of participants is followed over 10 years to determine the
development of diabetes. Which study design is this?
A. Case-control study
B. Cross-sectional study
C. Prospective cohort study
D. Case series
Correct Answer: C. Prospective cohort study
Rationale: A prospective cohort study follows a group of exposed and unexposed individuals forward in time to
measure the incidence of disease. This design is ideal for studying temporal relationships between risk factors and
outcomes.
3. In a case-control study, what is the primary measure of association used?
A. Relative risk (RR)
B. Odds ratio (OR)
C. Absolute risk reduction (ARR)
D. Number needed to treat (NNT)
Correct Answer: B. Odds ratio (OR)
Rationale: Case-control studies cannot directly calculate incidence rates, so the odds ratio (OR) is used as the measure
of association. The OR approximates the RR when the disease is rare in the population.
4. Which type of bias occurs when participants selected for a study differ systematically from the target
population?
A. Recall bias B. Information bias
C. Selection bias D. Confounding
Correct Answer: C. Selection bias
Rationale: Selection bias occurs when the study sample is not representative of the target population, often due to non-
random sampling, loss to follow-up, or volunteer bias. It threatens the external validity of study findings.
5. A cross-sectional survey administered at a single point in time measures the prevalence of hypertension in a
community. What is a key limitation of this design?
A. It cannot determine temporal sequence between exposure and outcome
B. It requires a very large sample size
2
, Epidemiology & Biostatistics Nursing Exam | 2026/2027
C. It is only useful for rare diseases
D. It always involves invasive procedures
Correct Answer: A. It cannot determine temporal sequence between exposure and outcome
Rationale: Cross-sectional studies capture a snapshot at one time point, making it impossible to determine whether the
exposure preceded the outcome. This limitation prevents causal inference despite being useful for estimating disease
prevalence.
6. A systematic review that uses statistical methods to combine results from multiple independent studies is best
described as:
A. A meta-analysis B. A narrative review
C. A scoping review D. An integrative review
Correct Answer: A. A meta-analysis
Rationale: A meta-analysis quantitatively combines data from multiple studies to produce a pooled effect estimate,
increasing statistical power and precision. It follows a rigorous protocol with inclusion criteria, quality assessment,
and heterogeneity evaluation.
Domain 2: Measures of Disease Frequency
7. In a city of 100,000 people, 500 new cases of tuberculosis were diagnosed in 2025. The incidence rate of
tuberculosis is:
A. 5 per 1,000 person-years
B. 50 per 1,000 person-years
C. 0.5 per 1,000 person-years
D. 500 per 100,000 person-years
Correct Answer: A. 5 per 1,000 person-years
Rationale: Incidence rate = (number of new cases / total person-time at risk). With 500 new cases in a population of
100,000, the rate is 500/100,000 = 5 per 1,000 person-years.
8. The number of existing cases of asthma in a community on January 1, 2026, divided by the total population on
that date represents the:
A. Incidence rate B. Point prevalence
C. Cumulative incidence D. Mortality rate
Correct Answer: B. Point prevalence
Rationale: Point prevalence measures the proportion of individuals with a disease at a specific point in time. It includes
both new and pre-existing cases and is useful for assessing the burden of disease in a population.
9. A nurse epidemiologist notes that the infant mortality rate in County A is 12 per 1,000 live births. This rate is
calculated as:
A. (Number of infant deaths / Total population) x 1,000
B. (Number of infant deaths under age 1 / Number of live births) x 1,000
C. (Number of infant deaths / Number of births including stillbirths) x 1,000
D. (Number of neonatal deaths / Total deaths) x 1,000
3
EPIDEMIOLOGY & BIOSTATISTICS NURSING EXAM
Data Interpretation | 2026/2027 Edition
60 Questions with Correct Answers and Rationales
Domain Questions Points
Study Design & Research Methodology 1–6
Measures of Disease Frequency 7–12
Risk Assessment (RR, OR, AR) 13–18
Statistical Inference & Hypothesis Testing 19–24
Data Interpretation & Graphical Analysis 25–30
Screening Test Validity (Sensitivity, Specificity, PPV/NPV) 31–36
Outbreak Investigation Principles 37–42
Evidence-Based Practice Application 43–48
Health Disparities & Population Health Metrics 49–54
Ethical Considerations in Epidemiologic Research 55–60
TOTAL 1–60 60
Instructions
• This examination consists of 60 multiple-choice questions covering 10 epidemiology and biostatistics domains.
• Select the single best answer for each question. Each correct answer is worth 1 point (Total: 60 points).
• Correct answers are displayed in bold cyan with a detailed rationale explaining epidemiologic and statistical
reasoning.
• All questions are aligned with CDC/WHO public health frameworks, AACN Essentials, and NCSBN competency
standards.
• Calculations and interpretive reasoning are emphasized; basic statistical formulas may be required.
Name: Date: ________________________ Score: _______ / 60
________________________
Domain 1: Study Design & Research Methodology
1
, Epidemiology & Biostatistics Nursing Exam | 2026/2027
1. Which study design provides the strongest evidence for establishing a cause-and-effect relationship between an
exposure and a disease?
A. Cross-sectional study
B. Case-control study
C. Randomized controlled trial
D. Ecological study
Correct Answer: C. Randomized controlled trial
Rationale: Randomized controlled trials (RCTs) are considered the gold standard for establishing causality because
randomization minimizes confounding and selection bias, allowing a direct comparison between intervention and
control groups.
2. A researcher conducts a study where a group of participants is followed over 10 years to determine the
development of diabetes. Which study design is this?
A. Case-control study
B. Cross-sectional study
C. Prospective cohort study
D. Case series
Correct Answer: C. Prospective cohort study
Rationale: A prospective cohort study follows a group of exposed and unexposed individuals forward in time to
measure the incidence of disease. This design is ideal for studying temporal relationships between risk factors and
outcomes.
3. In a case-control study, what is the primary measure of association used?
A. Relative risk (RR)
B. Odds ratio (OR)
C. Absolute risk reduction (ARR)
D. Number needed to treat (NNT)
Correct Answer: B. Odds ratio (OR)
Rationale: Case-control studies cannot directly calculate incidence rates, so the odds ratio (OR) is used as the measure
of association. The OR approximates the RR when the disease is rare in the population.
4. Which type of bias occurs when participants selected for a study differ systematically from the target
population?
A. Recall bias B. Information bias
C. Selection bias D. Confounding
Correct Answer: C. Selection bias
Rationale: Selection bias occurs when the study sample is not representative of the target population, often due to non-
random sampling, loss to follow-up, or volunteer bias. It threatens the external validity of study findings.
5. A cross-sectional survey administered at a single point in time measures the prevalence of hypertension in a
community. What is a key limitation of this design?
A. It cannot determine temporal sequence between exposure and outcome
B. It requires a very large sample size
2
, Epidemiology & Biostatistics Nursing Exam | 2026/2027
C. It is only useful for rare diseases
D. It always involves invasive procedures
Correct Answer: A. It cannot determine temporal sequence between exposure and outcome
Rationale: Cross-sectional studies capture a snapshot at one time point, making it impossible to determine whether the
exposure preceded the outcome. This limitation prevents causal inference despite being useful for estimating disease
prevalence.
6. A systematic review that uses statistical methods to combine results from multiple independent studies is best
described as:
A. A meta-analysis B. A narrative review
C. A scoping review D. An integrative review
Correct Answer: A. A meta-analysis
Rationale: A meta-analysis quantitatively combines data from multiple studies to produce a pooled effect estimate,
increasing statistical power and precision. It follows a rigorous protocol with inclusion criteria, quality assessment,
and heterogeneity evaluation.
Domain 2: Measures of Disease Frequency
7. In a city of 100,000 people, 500 new cases of tuberculosis were diagnosed in 2025. The incidence rate of
tuberculosis is:
A. 5 per 1,000 person-years
B. 50 per 1,000 person-years
C. 0.5 per 1,000 person-years
D. 500 per 100,000 person-years
Correct Answer: A. 5 per 1,000 person-years
Rationale: Incidence rate = (number of new cases / total person-time at risk). With 500 new cases in a population of
100,000, the rate is 500/100,000 = 5 per 1,000 person-years.
8. The number of existing cases of asthma in a community on January 1, 2026, divided by the total population on
that date represents the:
A. Incidence rate B. Point prevalence
C. Cumulative incidence D. Mortality rate
Correct Answer: B. Point prevalence
Rationale: Point prevalence measures the proportion of individuals with a disease at a specific point in time. It includes
both new and pre-existing cases and is useful for assessing the burden of disease in a population.
9. A nurse epidemiologist notes that the infant mortality rate in County A is 12 per 1,000 live births. This rate is
calculated as:
A. (Number of infant deaths / Total population) x 1,000
B. (Number of infant deaths under age 1 / Number of live births) x 1,000
C. (Number of infant deaths / Number of births including stillbirths) x 1,000
D. (Number of neonatal deaths / Total deaths) x 1,000
3
