Q1. Which measure of central tendency is most affected by outliers?
A) Median
B) Mode
C) Mean
D) Range
✓ Answer: C) Mean
Q2. The incidence rate measures:
A) Existing cases in a population at a point in time
B) New cases occurring in a population over a period of time
C) Deaths due to a specific disease
D) Proportion of people who recover from a disease
✓ Answer: B) New cases occurring in a population over a period of time
Q3. A study follows a group of healthy individuals over 20 years to identify
risk factors for heart disease. This is best described as:
A) Case-control study
B) Cross-sectional study
C) Prospective cohort study
D) Randomized controlled trial
✓ Answer: C) Prospective cohort study
Q4. Sensitivity of a diagnostic test refers to:
A) The probability of a positive test in people without the disease
B) The probability of a negative test in people without the disease
, C) The probability of a positive test in people with the disease
D) The probability of a negative test in people with the disease
✓ Answer: C) The probability of a positive test in people with the disease
Q5. Which type of bias occurs when study participants are not
representative of the target population?
A) Recall bias
B) Selection bias
C) Information bias
D) Confounding
✓ Answer: B) Selection bias
Q6. A p-value of 0.03 means:
A) There is a 3% probability the null hypothesis is true
B) There is a 97% probability the alternative hypothesis is true
C) If the null hypothesis is true, there is a 3% chance of observing results
as extreme as or more extreme than those obtained
D) The effect size is clinically significant
✓ Answer: C) If the null hypothesis is true, there is a 3% chance of
observing results as extreme as or more extreme than those obtained
Q7. The relative risk in a cohort study compares:
A) The odds of exposure among cases vs. controls
B) The incidence rate in exposed vs. unexposed groups
C) The prevalence in two different populations
D) Mortality rates between two groups
✓ Answer: B) The incidence rate in exposed vs. unexposed groups
Q8. Which epidemiological study design is best for studying rare
exposures?
A) Cohort study
B) Case-control study
C) Cross-sectional study
D) Ecological study
✓ Answer: A) Cohort study
Q9. Confounding in epidemiological studies occurs when:
A) A third variable is associated with both exposure and outcome
, B) The exposure causes the outcome
C) Participants are lost to follow-up
D) The study sample is too small
✓ Answer: A) A third variable is associated with both exposure and
outcome
Q10. The number needed to treat (NNT) is calculated as:
A) 1 / relative risk
B) 1 / absolute risk reduction
C) 1 / odds ratio
D) 1 / attributable risk
✓ Answer: B) 1 / absolute risk reduction
Q11. Which measure is most appropriate for comparing disease frequency
across populations with different age structures?
A) Crude mortality rate
B) Age-adjusted mortality rate
C) Incidence rate
D) Case fatality rate
✓ Answer: B) Age-adjusted mortality rate
Q12. An odds ratio of 1.0 indicates:
A) A strong positive association
B) A strong negative association
C) No association between exposure and outcome
D) A statistically significant association
✓ Answer: C) No association between exposure and outcome
Q13. The gold standard study design for establishing causation is:
A) Cohort study
B) Case-control study
C) Randomized controlled trial
D) Meta-analysis
✓ Answer: C) Randomized controlled trial
Q14. Positive predictive value (PPV) is influenced by:
A) Sensitivity only
, B) Specificity only
C) Disease prevalence, sensitivity, and specificity
D) Sample size only
✓ Answer: C) Disease prevalence, sensitivity, and specificity
Q15. The 'epidemic curve' in an outbreak investigation primarily helps to:
A) Identify the causative agent
B) Determine the mode of transmission and exposure period
C) Calculate the case fatality rate
D) Establish the reservoir of infection
✓ Answer: B) Determine the mode of transmission and exposure period
Q16. Which statistical test is appropriate for comparing means between
two independent groups when data are normally distributed?
A) Chi-square test
B) Mann-Whitney U test
C) Independent samples t-test
D) Pearson correlation
✓ Answer: C) Independent samples t-test
Q17. Attributable risk percent measures:
A) The proportion of disease in the exposed group attributable to the
exposure
B) The proportion of disease in the total population due to the exposure
C) The difference in risk between two populations
D) The ratio of incidence rates
✓ Answer: A) The proportion of disease in the exposed group
attributable to the exposure
Q18. Which of the following is a measure of disease burden?
A) Relative risk
B) Disability-Adjusted Life Year (DALY)
C) Odds ratio
D) Number needed to treat
✓ Answer: B) Disability-Adjusted Life Year (DALY)
Q19. In a 2x2 contingency table, the chi-square test evaluates:
A) The magnitude of association between two variables
A) Median
B) Mode
C) Mean
D) Range
✓ Answer: C) Mean
Q2. The incidence rate measures:
A) Existing cases in a population at a point in time
B) New cases occurring in a population over a period of time
C) Deaths due to a specific disease
D) Proportion of people who recover from a disease
✓ Answer: B) New cases occurring in a population over a period of time
Q3. A study follows a group of healthy individuals over 20 years to identify
risk factors for heart disease. This is best described as:
A) Case-control study
B) Cross-sectional study
C) Prospective cohort study
D) Randomized controlled trial
✓ Answer: C) Prospective cohort study
Q4. Sensitivity of a diagnostic test refers to:
A) The probability of a positive test in people without the disease
B) The probability of a negative test in people without the disease
, C) The probability of a positive test in people with the disease
D) The probability of a negative test in people with the disease
✓ Answer: C) The probability of a positive test in people with the disease
Q5. Which type of bias occurs when study participants are not
representative of the target population?
A) Recall bias
B) Selection bias
C) Information bias
D) Confounding
✓ Answer: B) Selection bias
Q6. A p-value of 0.03 means:
A) There is a 3% probability the null hypothesis is true
B) There is a 97% probability the alternative hypothesis is true
C) If the null hypothesis is true, there is a 3% chance of observing results
as extreme as or more extreme than those obtained
D) The effect size is clinically significant
✓ Answer: C) If the null hypothesis is true, there is a 3% chance of
observing results as extreme as or more extreme than those obtained
Q7. The relative risk in a cohort study compares:
A) The odds of exposure among cases vs. controls
B) The incidence rate in exposed vs. unexposed groups
C) The prevalence in two different populations
D) Mortality rates between two groups
✓ Answer: B) The incidence rate in exposed vs. unexposed groups
Q8. Which epidemiological study design is best for studying rare
exposures?
A) Cohort study
B) Case-control study
C) Cross-sectional study
D) Ecological study
✓ Answer: A) Cohort study
Q9. Confounding in epidemiological studies occurs when:
A) A third variable is associated with both exposure and outcome
, B) The exposure causes the outcome
C) Participants are lost to follow-up
D) The study sample is too small
✓ Answer: A) A third variable is associated with both exposure and
outcome
Q10. The number needed to treat (NNT) is calculated as:
A) 1 / relative risk
B) 1 / absolute risk reduction
C) 1 / odds ratio
D) 1 / attributable risk
✓ Answer: B) 1 / absolute risk reduction
Q11. Which measure is most appropriate for comparing disease frequency
across populations with different age structures?
A) Crude mortality rate
B) Age-adjusted mortality rate
C) Incidence rate
D) Case fatality rate
✓ Answer: B) Age-adjusted mortality rate
Q12. An odds ratio of 1.0 indicates:
A) A strong positive association
B) A strong negative association
C) No association between exposure and outcome
D) A statistically significant association
✓ Answer: C) No association between exposure and outcome
Q13. The gold standard study design for establishing causation is:
A) Cohort study
B) Case-control study
C) Randomized controlled trial
D) Meta-analysis
✓ Answer: C) Randomized controlled trial
Q14. Positive predictive value (PPV) is influenced by:
A) Sensitivity only
, B) Specificity only
C) Disease prevalence, sensitivity, and specificity
D) Sample size only
✓ Answer: C) Disease prevalence, sensitivity, and specificity
Q15. The 'epidemic curve' in an outbreak investigation primarily helps to:
A) Identify the causative agent
B) Determine the mode of transmission and exposure period
C) Calculate the case fatality rate
D) Establish the reservoir of infection
✓ Answer: B) Determine the mode of transmission and exposure period
Q16. Which statistical test is appropriate for comparing means between
two independent groups when data are normally distributed?
A) Chi-square test
B) Mann-Whitney U test
C) Independent samples t-test
D) Pearson correlation
✓ Answer: C) Independent samples t-test
Q17. Attributable risk percent measures:
A) The proportion of disease in the exposed group attributable to the
exposure
B) The proportion of disease in the total population due to the exposure
C) The difference in risk between two populations
D) The ratio of incidence rates
✓ Answer: A) The proportion of disease in the exposed group
attributable to the exposure
Q18. Which of the following is a measure of disease burden?
A) Relative risk
B) Disability-Adjusted Life Year (DALY)
C) Odds ratio
D) Number needed to treat
✓ Answer: B) Disability-Adjusted Life Year (DALY)
Q19. In a 2x2 contingency table, the chi-square test evaluates:
A) The magnitude of association between two variables
