ACVPM PRACTICE TEST QUESTIONS &
ANSWERS SOLVED 100% CORRECT 2026/2027
AMERICAN COLLEGE OF VETERINARY PREVENTIVE
MEDICINE
200 Questions with Complete Solutions | Board Certification Preparation
DOMAIN 1: EPIDEMIOLOGY (Questions 1-40)
1. Which measure of disease frequency represents the proportion of a population that has a
disease at a specific point in time?
A. Incidence rate
B. Prevalence
C. Cumulative incidence
D. Attack rate
Answer: B. Prevalence is a proportion measuring the amount of disease present in a
population at a specific point or period. Incidence measures new cases occurring in a
population at risk over a period.
2. In a cohort study investigating the association between a new feed additive and bovine
respiratory disease, the incidence of disease in the exposed group is 20% and in the unexposed
group is 5%. What is the risk ratio (Relative Risk)?
A. 0.25
B. 4.0
C. 15.0
D. 0.05
Answer: B. Risk Ratio = Incidence in exposed / Incidence in unexposed = 0..05 = 4.0.
The exposed animals are 4 times as likely to develop the disease.
3. A case-control study is conducted to investigate risk factors for feline hyperthyroidism. Which
measure of association is most appropriate to calculate?
,A. Risk Ratio
B. Rate Ratio
C. Odds Ratio
D. Attributable Risk
Answer: C. In case-control studies, the researcher selects cases and controls based on
disease status; therefore, the incidence of disease cannot be calculated directly. The Odds
Ratio (OR) is the appropriate measure of association.
4. Which type of bias occurs when study participants are lost to follow-up at different rates
between exposure groups, potentially distorting the observed association?
A. Selection bias
B. Information bias
C. Recall bias
D. Surveillance bias
Answer: A. Selection bias occurs when the method of selecting study participants results in
a sample that is not representative of the target population. Loss to follow-up differential
by exposure status is a classic form of selection bias.
5. A diagnostic test has a sensitivity of 95% and a specificity of 90%. If the test is applied to a
population with a very low prevalence of disease, what will happen to the positive predictive
value (PPV)?
A. It will increase.
B. It will decrease.
C. It will remain the same.
D. It will equal the negative predictive value.
Answer: B. PPV is heavily dependent on prevalence. As disease prevalence decreases, the
PPV decreases because the number of false positives rises relative to true positives.
6. What is the formula for calculating the confidence interval for a mean when the population
standard deviation is unknown and the sample size is small (n < 30)?
,A. Mean ± Z * (SD/sqrt(n))
B. Mean ± t * (SD/sqrt(n))
C. Mean ± Z * (SD/n)
D. Mean ± t * (SD/n)
Answer: B. When the population standard deviation is unknown and the sample size is
small, the t-distribution is used. The formula is Mean ± t * (Standard Error), where
Standard Error = SD/sqrt(n).
7. In an outbreak investigation of foodborne illness, the attack rate among people who ate potato
salad is 40%, while the attack rate among those who did not eat potato salad is 5%. What is the
attributable risk (risk difference)?
A. 8.0
B. 0.35 (35%)
C. 0.45 (45%)
D. 0.05 (5%)
Answer: B. Attributable Risk = Incidence in exposed - Incidence in unexposed = 0.40 - 0.05
= 0.35 or 35%. This represents the amount of disease risk attributable specifically to the
exposure.
8. Which study design is best for investigating a rare disease?
A. Cohort study
B. Cross-sectional study
C. Case-control study
D. Ecological study
Answer: C. Case-control studies are ideal for rare diseases because they start with
individuals who already have the disease (cases), avoiding the need to follow a large
population for a long time to wait for the disease to develop.
9. Herd immunity refers to:
A. The resistance of an individual animal to infection.
, B. The proportion of immune individuals in a population required to prevent epidemic
spread.
C. The immune response generated by a herd vaccination program.
D. The genetic resistance of a specific breed to a pathogen.
Answer: B. Herd immunity describes the indirect protection from infection conferred to
susceptible individuals in a population when a sufficient proportion of the population is
immune.
10. If a screening test has high sensitivity but low specificity, what is the likely outcome for the
patient?
A. High number of false negatives.
B. High number of false positives.
C. Accurate diagnosis for healthy patients.
D. High negative predictive value.
Answer: B. High sensitivity means the test correctly identifies most positive cases (few false
negatives). Low specificity means it incorrectly labels healthy individuals as positive (high
false positives).
11. An ecological fallacy occurs when:
A. An investigator assumes that a relationship observed at the group level applies to individuals.
B. Data is collected from the wrong ecosystem.
C. Environmental factors are ignored in the analysis.
D. A confounding variable relates to the geography.
Answer: A. An ecological fallacy is an error in interpretation where associations observed
at the population or group level are erroneously inferred to apply at the individual level.
12. Which of the following is NOT a criteria for causality (Hill’s Criteria)?
A. Strength of association
B. Temporality
ANSWERS SOLVED 100% CORRECT 2026/2027
AMERICAN COLLEGE OF VETERINARY PREVENTIVE
MEDICINE
200 Questions with Complete Solutions | Board Certification Preparation
DOMAIN 1: EPIDEMIOLOGY (Questions 1-40)
1. Which measure of disease frequency represents the proportion of a population that has a
disease at a specific point in time?
A. Incidence rate
B. Prevalence
C. Cumulative incidence
D. Attack rate
Answer: B. Prevalence is a proportion measuring the amount of disease present in a
population at a specific point or period. Incidence measures new cases occurring in a
population at risk over a period.
2. In a cohort study investigating the association between a new feed additive and bovine
respiratory disease, the incidence of disease in the exposed group is 20% and in the unexposed
group is 5%. What is the risk ratio (Relative Risk)?
A. 0.25
B. 4.0
C. 15.0
D. 0.05
Answer: B. Risk Ratio = Incidence in exposed / Incidence in unexposed = 0..05 = 4.0.
The exposed animals are 4 times as likely to develop the disease.
3. A case-control study is conducted to investigate risk factors for feline hyperthyroidism. Which
measure of association is most appropriate to calculate?
,A. Risk Ratio
B. Rate Ratio
C. Odds Ratio
D. Attributable Risk
Answer: C. In case-control studies, the researcher selects cases and controls based on
disease status; therefore, the incidence of disease cannot be calculated directly. The Odds
Ratio (OR) is the appropriate measure of association.
4. Which type of bias occurs when study participants are lost to follow-up at different rates
between exposure groups, potentially distorting the observed association?
A. Selection bias
B. Information bias
C. Recall bias
D. Surveillance bias
Answer: A. Selection bias occurs when the method of selecting study participants results in
a sample that is not representative of the target population. Loss to follow-up differential
by exposure status is a classic form of selection bias.
5. A diagnostic test has a sensitivity of 95% and a specificity of 90%. If the test is applied to a
population with a very low prevalence of disease, what will happen to the positive predictive
value (PPV)?
A. It will increase.
B. It will decrease.
C. It will remain the same.
D. It will equal the negative predictive value.
Answer: B. PPV is heavily dependent on prevalence. As disease prevalence decreases, the
PPV decreases because the number of false positives rises relative to true positives.
6. What is the formula for calculating the confidence interval for a mean when the population
standard deviation is unknown and the sample size is small (n < 30)?
,A. Mean ± Z * (SD/sqrt(n))
B. Mean ± t * (SD/sqrt(n))
C. Mean ± Z * (SD/n)
D. Mean ± t * (SD/n)
Answer: B. When the population standard deviation is unknown and the sample size is
small, the t-distribution is used. The formula is Mean ± t * (Standard Error), where
Standard Error = SD/sqrt(n).
7. In an outbreak investigation of foodborne illness, the attack rate among people who ate potato
salad is 40%, while the attack rate among those who did not eat potato salad is 5%. What is the
attributable risk (risk difference)?
A. 8.0
B. 0.35 (35%)
C. 0.45 (45%)
D. 0.05 (5%)
Answer: B. Attributable Risk = Incidence in exposed - Incidence in unexposed = 0.40 - 0.05
= 0.35 or 35%. This represents the amount of disease risk attributable specifically to the
exposure.
8. Which study design is best for investigating a rare disease?
A. Cohort study
B. Cross-sectional study
C. Case-control study
D. Ecological study
Answer: C. Case-control studies are ideal for rare diseases because they start with
individuals who already have the disease (cases), avoiding the need to follow a large
population for a long time to wait for the disease to develop.
9. Herd immunity refers to:
A. The resistance of an individual animal to infection.
, B. The proportion of immune individuals in a population required to prevent epidemic
spread.
C. The immune response generated by a herd vaccination program.
D. The genetic resistance of a specific breed to a pathogen.
Answer: B. Herd immunity describes the indirect protection from infection conferred to
susceptible individuals in a population when a sufficient proportion of the population is
immune.
10. If a screening test has high sensitivity but low specificity, what is the likely outcome for the
patient?
A. High number of false negatives.
B. High number of false positives.
C. Accurate diagnosis for healthy patients.
D. High negative predictive value.
Answer: B. High sensitivity means the test correctly identifies most positive cases (few false
negatives). Low specificity means it incorrectly labels healthy individuals as positive (high
false positives).
11. An ecological fallacy occurs when:
A. An investigator assumes that a relationship observed at the group level applies to individuals.
B. Data is collected from the wrong ecosystem.
C. Environmental factors are ignored in the analysis.
D. A confounding variable relates to the geography.
Answer: A. An ecological fallacy is an error in interpretation where associations observed
at the population or group level are erroneously inferred to apply at the individual level.
12. Which of the following is NOT a criteria for causality (Hill’s Criteria)?
A. Strength of association
B. Temporality
