STUDY GUIDE 2026 | 200+ VERIFIED
QUESTIONS & ANSWERS WITH DETAILED
RATIONALES
• This study guide contains 200 verified multiple-choice questions with detailed
EXPERT RATIONALE, designed to comprehensively prepare you for your PUBH210
Epidemiology exam — work through each question independently before checking
the answer, then study the EXPERT RATIONALE to reinforce your understanding.
• Features include bolded questions and answers, one-option-per-line
formatting, A–E answer choices, highlighted correct answers, and topic-wide
coverage — use it for timed practice, self-assessment, or last-minute review.
Q1. Which of the following best defines epidemiology?
A) The study of drugs and their effects on the human body
B) The study of the distribution and determinants of health-related states in
specified populations
C) The clinical management of infectious diseases in hospital settings
D) The study of individual patient outcomes in a clinical trial
E) The study of environmental pollutants and their toxic effects
✔ Correct Answer: B) The study of the distribution and determinants of
health-related states in specified populations EXPERT RATIONALE:
Epidemiology is classically defined as the study of the distribution (who, where,
when) and determinants (why, how) of health-related states or events in specified
populations, and the application of this study to control health problems.
Q2. The primary goal of epidemiology is to:
A) Treat individual patients with infectious diseases
B) Develop new pharmaceutical drugs
C) Prevent and control disease at the population level
,D) Conduct laboratory analysis of blood samples
E) Provide surgical interventions to communities
✔ Correct Answer: C) Prevent and control disease at the population level
EXPERT RATIONALE: While epidemiology informs clinical medicine, its primary goal
is the prevention and control of disease at the population level by identifying risk
factors, causes, and effective interventions.
Q3. Which of the following is NOT a core function of epidemiology?
A) Describing the distribution of disease
B) Identifying causes and risk factors
C) Prescribing medications to patients
D) Evaluating preventive and therapeutic interventions
E) Providing data for health policy decisions
✔ Correct Answer: C) Prescribing medications to patients EXPERT RATIONALE:
Prescribing medications is a clinical function, not an epidemiological one.
Epidemiology focuses on populations — describing disease patterns, identifying
causes, evaluating interventions, and informing policy.
Q4. John Snow's investigation of the 1854 London cholera outbreak is
considered a landmark in epidemiology because he:
A) Discovered the cholera bacterium under a microscope
B) Identified the Broad Street pump as the source through systematic mapping
C) Developed the first cholera vaccine
D) Conducted the first randomized controlled trial
E) Proved that cholera was caused by foul-smelling air
,✔ Correct Answer: B) Identified the Broad Street pump as the source through
systematic mapping EXPERT RATIONALE: John Snow mapped cholera cases and
traced the outbreak to the Broad Street water pump, demonstrating a waterborne
transmission route long before the cholera bacterium was identified — establishing
foundational epidemiological methods.
Q5. Descriptive epidemiology characterizes disease occurrence according to:
A) Person, place, and time
B) Odds ratio, relative risk, and attributable risk
C) Incidence, prevalence, and mortality only
D) Exposure, confounder, and outcome
E) Sensitivity, specificity, and predictive value
✔ Correct Answer: A) Person, place, and time EXPERT RATIONALE: Descriptive
epidemiology characterizes health events by person (who is affected), place (where
it occurs), and time (when it occurs) to generate hypotheses about causes and risk
factors.
Q6. Incidence rate is best defined as:
A) The proportion of a population with a disease at a single point in time
B) The number of new cases of disease occurring in a population at risk during a
specified time period
C) The total number of existing cases in a population
D) The number of deaths due to a disease per 100,000 population
E) The ratio of exposed to unexposed individuals developing disease
✔ Correct Answer: B) The number of new cases of disease occurring in a
population at risk during a specified time period EXPERT RATIONALE: Incidence
, measures new cases in a defined population at risk over a specified time, making it
the key measure of disease risk and transition from health to disease.
Q7. Prevalence is best described as:
A) The rate at which new cases of disease develop
B) The proportion of individuals in a population who have a disease at a given point
or period in time
C) The probability of dying from a disease
D) The number of deaths per live births
E) The proportion of exposed individuals who develop disease
✔ Correct Answer: B) The proportion of individuals in a population who have a
disease at a given point or period in time EXPERT RATIONALE: Prevalence
measures the proportion of a population that has a disease at a specific point
(point prevalence) or during a period (period prevalence). It reflects disease burden
in a population.
Q8. Which of the following correctly expresses the relationship between
prevalence, incidence, and duration of disease?
A) Prevalence = Incidence × Mortality
B) Prevalence ≈ Incidence Rate × Average Duration of Disease
C) Incidence = Prevalence / Duration
D) Prevalence = Incidence + Duration
E) Prevalence = Incidence Rate / Population size
✔ Correct Answer: B) Prevalence ≈ Incidence Rate × Average Duration of
Disease EXPERT RATIONALE: For a stable population with a low prevalence,
prevalence ≈ incidence rate × mean duration of disease. This relationship shows