#1
Which of the following is a measure of disease frequency in a population?
Prevalence
ExplanationPrevalence measures the total number of cases within a population at a specific time.
#2
What is the purpose of a case-control study in epidemiology?
To identify risk factors for a disease by comparing individuals with and without the disease.
ExplanationCase-control studies help determine associations between exposures and specific outcomes.
#3
Which of the following is NOT a component of the epidemiological triad?
Treatment
ExplanationTreatment is not a component; rather, the triad consists of host, agent, and environment.
#4
In epidemiology, what does the term 'cohort' refer to?
A group of individuals followed over time to study the occurrence of an outcome.
ExplanationCohorts track individuals to observe outcomes over time, aiding in understanding disease development.
#5
Which statistical test is commonly used to compare means between two groups in epidemiological studies?
T-test
ExplanationThe t-test assesses if there is a significant difference between means of two groups.
#6
What is the difference between prevalence and incidence?
Prevalence measures the total number of cases, while incidence measures the number of new cases.
ExplanationPrevalence reflects existing cases, while incidence represents new occurrences over time.
#7
Which study design is best suited for assessing the cause-effect relationship between an exposure and an outcome?
Randomized controlled trial
ExplanationRandomized controlled trials allow for controlled testing of causal relationships.
#8
What is herd immunity?
The resistance of a group to the spread of a disease due to a high proportion of individuals immune to the disease.
ExplanationHerd immunity protects unvaccinated individuals by limiting the disease's transmission within a population.
#9
What is the main purpose of randomization in a randomized controlled trial (RCT)?
To minimize bias and confounding factors between treatment groups.
ExplanationRandomization ensures that treatment groups are comparable, reducing the influence of variables.
#10
What does odds ratio (OR) measure in epidemiology?
The strength of association between exposure and outcome.
ExplanationOdds ratio quantifies the likelihood of an outcome given exposure compared to non-exposure.
#11
What is the basic reproduction number (R₀) of a disease?
The average number of secondary cases generated by a single primary case in a susceptible population.
ExplanationR₀ indicates the contagiousness of a disease, affecting its potential spread.
#12
What is a confounding variable in epidemiological studies?
A variable that distorts the true association between exposure and outcome.
ExplanationConfounding variables obscure the relationship between the exposure and outcome of interest.
#13
What is the primary purpose of stratification in epidemiological analysis?
To identify effect modification by subgroup analysis.
ExplanationStratification helps reveal how the relationship between exposure and outcome varies across different subgroups.