Free Epidemiology and Biostatistics MCQs with Answers
50 Epidemiology and Biostatistics MCQs from Community Health Nursing, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Epidemiology examines the distribution and causes of disease by person, place and time, using measures such as incidence, prevalence, mortality and case-fatality rates. Biostatistics covers data presentation, sampling, averages, variability, probability and interpretation of study results, while distinguishing association from causation.
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50 questions · page 2 of 3
- A. Person distribution
- B. Place distribution
- C. Time distribution
- D. Seasonal variation
Explanation: Person distribution describes disease occurrence according to characteristics such as age, sex, occupation or education.
Correct answer: Person distribution- A. Case-control study
- B. Cohort study
- C. Cross-sectional study
- D. Ecological study
Explanation: A case-control study begins with disease status and looks backward to compare past exposures.
Correct answer: Case-control study- A. 5 percentage points
- B. 15 percentage points
- C. 25 percentage points
- D. 400 percentage points
Explanation: Attributable risk is the risk in the exposed group minus the risk in the unexposed group: 20% minus 5% equals 15 percentage points.
Correct answer: 15 percentage points- A. 24 divided by 12,000, multiplied by 100,000
- B. 12,000 divided by 24, multiplied by 100,000
- C. 24 divided by total population, multiplied by 1,000
- D. 12,000 divided by total population, multiplied by 1,000
Explanation: The maternal mortality ratio is maternal deaths divided by live births, multiplied by 100,000.
Correct answer: 24 divided by 12,000, multiplied by 100,00025. The numbers of antenatal visits made by five women are 2, 3, 3, 4 and 6. Which measure is the mode?
- A. 2 visits
- B. 3 visits
- C. 4 visits
- D. 6 visits
Explanation: The mode is the value that occurs most frequently in a data set. The value 3 occurs twice, while every other value occurs once.
Correct answer: 3 visits- A. 0.5°C
- B. 1.0°C
- C. 1.5°C
- D. 2.0°C
Explanation: Range is calculated by subtracting the lowest value from the highest value. Therefore, 38.0°C minus 36.5°C equals 1.5°C.
Correct answer: 1.5°C- A. Cluster sampling
- B. Systematic sampling
- C. Convenience sampling
- D. Purposive sampling
Explanation: Cluster sampling selects naturally occurring groups, such as households or villages, and studies members within the selected groups.
Correct answer: Cluster sampling- A. Two households must be selected
- B. Twenty households are already selected
- C. Each household has a 20% selection chance
- D. The survey has a 20% response rate
Explanation: A probability of 0.2 is equivalent to a 20% chance of selection for that household.
Correct answer: Each household has a 20% selection chance- A. The association is seen only in one small village
- B. Malaria occurred before bed nets were introduced
- C. The association persists after important confounders are controlled
- D. People who use bed nets also report more health visits
Explanation: An association that remains after controlling for important confounding factors provides stronger evidence that the exposure may have a…
Correct answer: The association persists after important confounders are controlled- A. Histogram
- B. Pie chart
- C. Bar chart of blood groups
- D. Line list of patient names
Explanation: A histogram displays the frequency distribution of continuous numerical data across intervals.
Correct answer: Histogram- A. Sporadic disease
- B. Endemic disease
- C. Epidemic disease
- D. Pandemic disease
Explanation: An endemic disease remains continuously present at an expected level in a defined area.
Correct answer: Endemic disease- A. High sensitivity
- B. High specificity
- C. High incidence
- D. High case-fatality rate
Explanation: High specificity correctly identifies people who do not have the disease and therefore reduces false-positive results.
Correct answer: High specificity- A. Exposed people have three times the disease incidence
- B. Cases have three times the odds of past exposure
- C. The exposure causes exactly three extra cases
- D. Three percent of exposed people develop disease
Explanation: An odds ratio of 3.0 means the odds of previous exposure are three times higher among cases than controls.
Correct answer: Cases have three times the odds of past exposure- A. The association is statistically significant at 5%
- B. The relative risk is exactly 1.2
- C. The interval includes no difference between groups
- D. The exposed group has no disease cases
Explanation: For a relative risk, a value of 1 represents no difference between groups, and this interval includes 1.
Correct answer: The interval includes no difference between groups- A. Cluster sampling
- B. Systematic sampling
- C. Convenience sampling
- D. Purposive sampling
Explanation: Cluster sampling selects naturally occurring groups, such as village sections, and then studies members within the selected groups.
Correct answer: Cluster sampling- A. The spread of individual observations
- B. The expected variation of sample means
- C. The number of missing observations
- D. The percentage of diseased participants
Explanation: The standard error describes how much sample means are expected to vary from sample to sample.
Correct answer: The expected variation of sample means- A. The nurses selected the training themselves
- B. The study measured errors after training only
- C. Nurses were randomly assigned to training groups
- D. The training group was larger than the control group
Explanation: Random assignment helps balance known and unknown confounding factors between groups.
Correct answer: Nurses were randomly assigned to training groups- A. Propagated epidemic
- B. Point-source epidemic
- C. Endemic pattern
- D. Seasonal variation
Explanation: A point-source epidemic occurs when many people are exposed to a common source at one time, producing a sharp concentration of cases.
Correct answer: Point-source epidemic- A. Pie chart
- B. Scatter plot
- C. Histogram
- D. Line graph
Explanation: A pie chart shows how categories make up parts of a whole, such as immunised and unimmunised children.
Correct answer: Pie chart- A. Effect modification
- B. Random error
- C. Selection bias
- D. Recall bias
Explanation: Effect modification occurs when the strength or direction of an association differs across levels of another variable, such as sex.
Correct answer: Effect modification