#1
What is the difference between incidence and prevalence?
Incidence refers to the number of new cases occurring in a population over a defined period of time, while prevalence refers to the proportion of individuals with a particular disease at a specific point in time.
ExplanationIncidence reflects new cases; prevalence reflects existing cases.
#2
What is herd immunity?
The immunity acquired by a population through vaccination or previous exposure to a disease, reducing the likelihood of disease transmission
ExplanationHerd immunity protects the unvaccinated.
#3
Which of the following is NOT a common measure of central tendency?
Standard deviation
ExplanationStandard deviation measures dispersion.
#4
What is the purpose of a case-control study?
To identify risk factors for a disease by comparing individuals with and without the disease
ExplanationCase-control studies analyze past exposures.
#5
What is the purpose of surveillance in epidemiology?
To identify outbreaks and trends in disease occurrence
ExplanationSurveillance aids in early detection.
#6
What is the primary goal of outbreak investigation in epidemiology?
To identify and control the source of an infectious disease outbreak
ExplanationOutbreak investigations prevent disease spread.
#7
What is the basic reproductive number (R0) in epidemiology?
The number of secondary cases produced by a single infected individual in a susceptible population
ExplanationR0 measures the potential for disease spread.
#8
What is the purpose of randomization in experimental studies?
To ensure equal allocation of participants to treatment groups
ExplanationRandomization minimizes selection bias.
#9
Which of the following is a measure of association used in epidemiological studies?
Odds ratio
ExplanationOdds ratio quantifies the likelihood of an event.
#10
What is the purpose of stratification in epidemiological analysis?
To adjust for confounding variables
ExplanationStratification enhances analysis accuracy.
#11
What is the difference between an epidemic and a pandemic?
An epidemic is limited to a specific region, while a pandemic occurs globally.
ExplanationPandemics spread globally; epidemics are localized.
#12
Which of the following is a measure of association used in cohort studies?
Relative risk
ExplanationRelative risk assesses the risk in exposed vs. unexposed.
#13
Which study design is best suited for determining causality in epidemiology?
Randomized controlled trial
ExplanationRCTs allow control over confounding variables.
#14
What is the purpose of a sensitivity analysis in epidemiological modeling?
To determine the impact of uncertainty in model parameters on model outputs
ExplanationSensitivity analysis assesses model robustness.
#15
What is the concept of confounding in epidemiology?
The distortion of an observed association due to a third variable that is related to both the exposure and outcome
ExplanationConfounding masks true relationships.
#16
Which of the following is NOT a criterion for establishing causality proposed by Sir Austin Bradford Hill?
Specificity
ExplanationSpecificity is not required to infer causation.
#17
What is the concept of attribution in epidemiology?
The estimation of the proportion of disease burden attributable to a specific risk factor
ExplanationAttribution quantifies risk factor impact.
#18
What is the purpose of the dose-response relationship in epidemiological studies?
To evaluate the relationship between exposure intensity and disease risk
ExplanationDose-response analysis elucidates exposure effects.