EPIDEMIOLOGY EXAM – PRACTICE QUESTIONS AND CORRECT ANSWERS (VERIFIED
ANSWERS) PLUS RATIONALES 2026 Q&A | INSTANT DOWNLOAD PDF.
*CORE DOMAINS*
*Principles of Disease Transmission*
*Measures of Morbidity and Mortality*
*Study Design and Methodology*
*Outbreak Investigation and Management*
*Screening and Diagnostic Tests*
*Biostatistics and Data Analysis*
*Ethical Conduct in Human Research*
*Environmental and Social Determinants*
*INTRODUCTION*
The purpose of this comprehensive assessment is to evaluate the candidate's mastery of
fundamental and advanced epidemiological concepts. This examination assesses skills in data
interpretation, the application of study designs, and the ability to identify patterns of health and
disease within diverse populations. Through a combination of multiple-choice and complex
scenario-based questions, the exam tests the ability to synthesize theoretical knowledge with real-
world public health challenges. Emphasis is placed on evidence-based decision-making, ethical
research practices, and the legal frameworks governing public health surveillance. Candidates must
demonstrate critical thinking to navigate variables and biases inherent in population health
research.
**SECTION ONE**
1. Which of the following best describes the primary focus of epidemiology?
,A. The clinical treatment of individual patients in a hospital setting.
B. The study of the distribution and determinants of health-related states in populations.
C. The development of new pharmacological agents for rare genetic diseases.
D. The physiological mechanisms of cellular degeneration.
🟢 B. The study of the distribution and determinants of health-related states in populations.
🔴 RATIONALE: Epidemiology is defined as the study of how often diseases occur in different
groups of people and why, focusing on populations rather than individuals.
2. In a population of 50,000 people, 500 cases of a specific disease are identified on January
1st. During the year, 100 new cases develop. What is the point prevalence on January 1st?
A. 1%
B. 2%
C. 5%
D. 10%
🟢 A. 1%
🔴 RATIONALE: Point prevalence is calculated by dividing the number of existing cases (500) by
the total population (50,000), which equals 0.01 or 1%.
3. A researcher is studying a rare disease and decides to compare individuals who have the
disease with a group of similar individuals who do not. This is an example of a:
A. Cohort study
B. Randomized controlled trial
C. Case-control study
D. Cross-sectional study
🟢 C. Case-control study
🔴 RATIONALE: Case-control studies are retrospective and specifically useful for rare diseases, as
they start with the outcome and look back at exposures.
, 4. Which measure of central tendency is most affected by extreme outliers in a skewed
distribution?
A. Median
B. Mode
C. Mean
D. Range
🟢 C. Mean
🔴 RATIONALE: The mean is calculated by summing all values; therefore, unusually high or low
values significantly shift the average, unlike the median or mode.
5. A screening test for a new virus has high sensitivity. This means the test:
A. Is very good at identifying those who do not have the disease.
B. Produces very few false positives.
C. Is very good at identifying those who actually have the disease.
D. Is only effective in symptomatic patients.
🟢 C. Is very good at identifying those who actually have the disease.
🔴 RATIONALE: Sensitivity measures the proportion of actual positives that are correctly
identified as such (true positive rate).
6. In an outbreak of food poisoning, 80 people ate potato salad and 40 of them became ill.
What is the attack rate among those who ate the potato salad?
A. 25%
B. 50%
C. 75%
D. 40%
🟢 B. 50%
, 🔴 RATIONALE: The attack rate is calculated as the number of new cases (40) divided by the total
population at risk (80), resulting in 50%.
7. Which of the following is an example of primary prevention?
A. Routine mammography for breast cancer screening.
B. Physical therapy after a stroke.
C. Immunization against measles, mumps, and rubella.
D. Surgical removal of a localized tumor.
🟢 C. Immunization against measles, mumps, and rubella.
🔴 RATIONALE: Primary prevention aims to prevent the onset of disease through measures such
as vaccination or lifestyle changes.
8. A study finds a Relative Risk (RR) of 1.0 for the association between coffee consumption
and pancreatic cancer. This indicates:
A. Coffee increases the risk of cancer.
B. Coffee decreases the risk of cancer.
C. There is no association between the exposure and the outcome.
D. The study results are invalid.
🟢 C. There is no association between the exposure and the outcome.
🔴 RATIONALE: An RR of 1.0 means the risk in the exposed group is exactly the same as the risk
in the unexposed group.
9. What is the term for the interval between the receipt of infection and the maximal
infectivity of the host?
A. Incubation period
B. Latent period
ANSWERS) PLUS RATIONALES 2026 Q&A | INSTANT DOWNLOAD PDF.
*CORE DOMAINS*
*Principles of Disease Transmission*
*Measures of Morbidity and Mortality*
*Study Design and Methodology*
*Outbreak Investigation and Management*
*Screening and Diagnostic Tests*
*Biostatistics and Data Analysis*
*Ethical Conduct in Human Research*
*Environmental and Social Determinants*
*INTRODUCTION*
The purpose of this comprehensive assessment is to evaluate the candidate's mastery of
fundamental and advanced epidemiological concepts. This examination assesses skills in data
interpretation, the application of study designs, and the ability to identify patterns of health and
disease within diverse populations. Through a combination of multiple-choice and complex
scenario-based questions, the exam tests the ability to synthesize theoretical knowledge with real-
world public health challenges. Emphasis is placed on evidence-based decision-making, ethical
research practices, and the legal frameworks governing public health surveillance. Candidates must
demonstrate critical thinking to navigate variables and biases inherent in population health
research.
**SECTION ONE**
1. Which of the following best describes the primary focus of epidemiology?
,A. The clinical treatment of individual patients in a hospital setting.
B. The study of the distribution and determinants of health-related states in populations.
C. The development of new pharmacological agents for rare genetic diseases.
D. The physiological mechanisms of cellular degeneration.
🟢 B. The study of the distribution and determinants of health-related states in populations.
🔴 RATIONALE: Epidemiology is defined as the study of how often diseases occur in different
groups of people and why, focusing on populations rather than individuals.
2. In a population of 50,000 people, 500 cases of a specific disease are identified on January
1st. During the year, 100 new cases develop. What is the point prevalence on January 1st?
A. 1%
B. 2%
C. 5%
D. 10%
🟢 A. 1%
🔴 RATIONALE: Point prevalence is calculated by dividing the number of existing cases (500) by
the total population (50,000), which equals 0.01 or 1%.
3. A researcher is studying a rare disease and decides to compare individuals who have the
disease with a group of similar individuals who do not. This is an example of a:
A. Cohort study
B. Randomized controlled trial
C. Case-control study
D. Cross-sectional study
🟢 C. Case-control study
🔴 RATIONALE: Case-control studies are retrospective and specifically useful for rare diseases, as
they start with the outcome and look back at exposures.
, 4. Which measure of central tendency is most affected by extreme outliers in a skewed
distribution?
A. Median
B. Mode
C. Mean
D. Range
🟢 C. Mean
🔴 RATIONALE: The mean is calculated by summing all values; therefore, unusually high or low
values significantly shift the average, unlike the median or mode.
5. A screening test for a new virus has high sensitivity. This means the test:
A. Is very good at identifying those who do not have the disease.
B. Produces very few false positives.
C. Is very good at identifying those who actually have the disease.
D. Is only effective in symptomatic patients.
🟢 C. Is very good at identifying those who actually have the disease.
🔴 RATIONALE: Sensitivity measures the proportion of actual positives that are correctly
identified as such (true positive rate).
6. In an outbreak of food poisoning, 80 people ate potato salad and 40 of them became ill.
What is the attack rate among those who ate the potato salad?
A. 25%
B. 50%
C. 75%
D. 40%
🟢 B. 50%
, 🔴 RATIONALE: The attack rate is calculated as the number of new cases (40) divided by the total
population at risk (80), resulting in 50%.
7. Which of the following is an example of primary prevention?
A. Routine mammography for breast cancer screening.
B. Physical therapy after a stroke.
C. Immunization against measles, mumps, and rubella.
D. Surgical removal of a localized tumor.
🟢 C. Immunization against measles, mumps, and rubella.
🔴 RATIONALE: Primary prevention aims to prevent the onset of disease through measures such
as vaccination or lifestyle changes.
8. A study finds a Relative Risk (RR) of 1.0 for the association between coffee consumption
and pancreatic cancer. This indicates:
A. Coffee increases the risk of cancer.
B. Coffee decreases the risk of cancer.
C. There is no association between the exposure and the outcome.
D. The study results are invalid.
🟢 C. There is no association between the exposure and the outcome.
🔴 RATIONALE: An RR of 1.0 means the risk in the exposed group is exactly the same as the risk
in the unexposed group.
9. What is the term for the interval between the receipt of infection and the maximal
infectivity of the host?
A. Incubation period
B. Latent period
