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EPIDEMIOLOGY AND PUBLIC HEALTH
NR442 QUESTIONS AND ANSWERS
1. **A public health nurse (PHN) investigates a cluster of Legionnaires’
disease. Which epidemiological model is most appropriate?**
a) Epidemiological triangle
b) Web of causation
c) Health belief model
d) Transtheoretical model
**Answer: a** – The epidemiological triangle (agent, host,
environment) is classic for infectious disease outbreaks. Web of
causation is for chronic diseases.
2. **Which term describes the number of new cases of hypertension in
a city over one year?**
a) Prevalence
b) Incidence
c) Attack rate
d) Case fatality rate
, **Answer: b** – Incidence = new cases / population at risk over time.
Prevalence = all existing cases.
3. **A PHN calculates the number of deaths from opioid overdose per
100,000 population. This is a:**
a) Crude mortality rate
b) Cause-specific mortality rate
c) Proportional mortality ratio
d) Case fatality rate
**Answer: b** – Cause-specific mortality rate focuses on deaths from
a specific cause.
4. **During a foodborne outbreak, 60 of 200 people who ate potato
salad became ill. What is the attack rate?**
a) 10%
b) 20%
c) 30%
d) 40%
**Answer: c** – (60 ill / 200 exposed) × 100 = 30%.
5. **Which measure helps determine the burden of diabetes in a
community at a single point in time?**
a) Incidence rate
, b) Point prevalence
c) Period prevalence
d) Mortality rate
**Answer: b** – Point prevalence measures existing cases at a
specific time.
6. **A screening test correctly identifies 90% of people with HIV. This
describes:**
a) Specificity
b) Sensitivity
c) Positive predictive value
d) Negative predictive value
**Answer: b** – Sensitivity = ability to correctly identify those WITH
the disease.
7. **A test has 95% specificity. This means:**
a) 5% false negatives
b) 95% true negatives
c) 95% true positives
d) 5% false positives
**Answer: b** – Specificity = true negatives / (true negatives + false
positives).
, 8. **In a community with low disease prevalence, which value is most
affected?**
a) Sensitivity
b) Specificity
c) Positive predictive value (PPV)
d) Reliability
**Answer: c** – PPV decreases as prevalence decreases (more false
positives).
9. **A PHN uses the number of years of potential life lost (YPLL) to
prioritize:**
a) Chronic disease screening
b) Prevention of premature deaths
c) Infectious disease reporting
d) Environmental health risks
**Answer: b** – YPLL highlights deaths occurring at younger ages.
10. **Which study design is best for investigating a rare disease
etiology?**
a) Cross-sectional
b) Case-control
c) Cohort
d) Randomized controlled trial
EPIDEMIOLOGY AND PUBLIC HEALTH
NR442 QUESTIONS AND ANSWERS
1. **A public health nurse (PHN) investigates a cluster of Legionnaires’
disease. Which epidemiological model is most appropriate?**
a) Epidemiological triangle
b) Web of causation
c) Health belief model
d) Transtheoretical model
**Answer: a** – The epidemiological triangle (agent, host,
environment) is classic for infectious disease outbreaks. Web of
causation is for chronic diseases.
2. **Which term describes the number of new cases of hypertension in
a city over one year?**
a) Prevalence
b) Incidence
c) Attack rate
d) Case fatality rate
, **Answer: b** – Incidence = new cases / population at risk over time.
Prevalence = all existing cases.
3. **A PHN calculates the number of deaths from opioid overdose per
100,000 population. This is a:**
a) Crude mortality rate
b) Cause-specific mortality rate
c) Proportional mortality ratio
d) Case fatality rate
**Answer: b** – Cause-specific mortality rate focuses on deaths from
a specific cause.
4. **During a foodborne outbreak, 60 of 200 people who ate potato
salad became ill. What is the attack rate?**
a) 10%
b) 20%
c) 30%
d) 40%
**Answer: c** – (60 ill / 200 exposed) × 100 = 30%.
5. **Which measure helps determine the burden of diabetes in a
community at a single point in time?**
a) Incidence rate
, b) Point prevalence
c) Period prevalence
d) Mortality rate
**Answer: b** – Point prevalence measures existing cases at a
specific time.
6. **A screening test correctly identifies 90% of people with HIV. This
describes:**
a) Specificity
b) Sensitivity
c) Positive predictive value
d) Negative predictive value
**Answer: b** – Sensitivity = ability to correctly identify those WITH
the disease.
7. **A test has 95% specificity. This means:**
a) 5% false negatives
b) 95% true negatives
c) 95% true positives
d) 5% false positives
**Answer: b** – Specificity = true negatives / (true negatives + false
positives).
, 8. **In a community with low disease prevalence, which value is most
affected?**
a) Sensitivity
b) Specificity
c) Positive predictive value (PPV)
d) Reliability
**Answer: c** – PPV decreases as prevalence decreases (more false
positives).
9. **A PHN uses the number of years of potential life lost (YPLL) to
prioritize:**
a) Chronic disease screening
b) Prevention of premature deaths
c) Infectious disease reporting
d) Environmental health risks
**Answer: b** – YPLL highlights deaths occurring at younger ages.
10. **Which study design is best for investigating a rare disease
etiology?**
a) Cross-sectional
b) Case-control
c) Cohort
d) Randomized controlled trial
