,ATI RN Community Health Proctored Exam
Practice Test + 150 Community Nursing
Questions & Rationales
1. A community health nurse is calculating the incidence rate of a disease. Which formula
should the nurse use?
A. (Total existing cases ÷ population) × 100,000
B. (New cases ÷ population at risk) × 100,000
C. (Deaths ÷ total cases) × 100,000
D. (Existing cases at a point in time ÷ population) × 100,000
Correct Answer: B. Incidence rate measures the number of new cases of a disease in a
population at risk during a specified time period. It is calculated as (new cases ÷ population at
risk) × multiplier.
Rationale: Incidence reflects the risk of developing a disease. Prevalence (A and D) measures all
existing cases at a given time. Attack rate is a synonym for incidence proportion used in
outbreak settings.
2. A community health nurse is investigating a foodborne illness outbreak at a church picnic. Of
the 120 people who attended, 45 became ill. What is the attack rate?
A. 37.5%
,B. 45%
C. 26.7%
D. 62.5%
Correct Answer: A. Attack rate = (ill ÷ exposed) × 100 = (45 ÷ 120) × 100 = 37.5%.
Rationale: Attack rate is used during outbreak investigations to quantify the risk of illness among
those exposed. It is a synonym for incidence proportion.
3. A nurse is teaching a community group about the epidemiological triangle. Which three
components make up this model?
A. Agent, host, environment
B. Incidence, prevalence, mortality
C. Primary, secondary, tertiary prevention
D. Screening, treatment, rehabilitation
Correct Answer: A. The epidemiological triangle consists of three elements: Agent (causative
organism), Host (susceptible individual), and Environment (conditions that support
transmission).
Rationale: This model helps nurses understand the multifactorial nature of disease causation.
Breaking any link in the triangle can interrupt disease transmission.
, 4. A community health nurse is tracking the number of existing cases of diabetes in a county at a
specific point in time. Which measure is the nurse calculating?
A. Incidence rate
B. Attack rate
C. Point prevalence
D. Mortality rate
Correct Answer: C. Point prevalence measures the total number of existing cases at a specific
point in time.
Rationale: Prevalence = all existing cases ÷ population × multiplier. Incidence measures only new
cases. The "bathtub model" helps distinguish: incidence is water flowing in, prevalence is the
water level.
5. A nurse is screening for tuberculosis at a homeless shelter. Which level of prevention does
this activity represent?
A. Primary prevention
B. Secondary prevention
C. Tertiary prevention
D. Quaternary prevention
Correct Answer: B. Secondary prevention involves early detection and prompt treatment of
disease through screening, case finding, and diagnostic testing.
Practice Test + 150 Community Nursing
Questions & Rationales
1. A community health nurse is calculating the incidence rate of a disease. Which formula
should the nurse use?
A. (Total existing cases ÷ population) × 100,000
B. (New cases ÷ population at risk) × 100,000
C. (Deaths ÷ total cases) × 100,000
D. (Existing cases at a point in time ÷ population) × 100,000
Correct Answer: B. Incidence rate measures the number of new cases of a disease in a
population at risk during a specified time period. It is calculated as (new cases ÷ population at
risk) × multiplier.
Rationale: Incidence reflects the risk of developing a disease. Prevalence (A and D) measures all
existing cases at a given time. Attack rate is a synonym for incidence proportion used in
outbreak settings.
2. A community health nurse is investigating a foodborne illness outbreak at a church picnic. Of
the 120 people who attended, 45 became ill. What is the attack rate?
A. 37.5%
,B. 45%
C. 26.7%
D. 62.5%
Correct Answer: A. Attack rate = (ill ÷ exposed) × 100 = (45 ÷ 120) × 100 = 37.5%.
Rationale: Attack rate is used during outbreak investigations to quantify the risk of illness among
those exposed. It is a synonym for incidence proportion.
3. A nurse is teaching a community group about the epidemiological triangle. Which three
components make up this model?
A. Agent, host, environment
B. Incidence, prevalence, mortality
C. Primary, secondary, tertiary prevention
D. Screening, treatment, rehabilitation
Correct Answer: A. The epidemiological triangle consists of three elements: Agent (causative
organism), Host (susceptible individual), and Environment (conditions that support
transmission).
Rationale: This model helps nurses understand the multifactorial nature of disease causation.
Breaking any link in the triangle can interrupt disease transmission.
, 4. A community health nurse is tracking the number of existing cases of diabetes in a county at a
specific point in time. Which measure is the nurse calculating?
A. Incidence rate
B. Attack rate
C. Point prevalence
D. Mortality rate
Correct Answer: C. Point prevalence measures the total number of existing cases at a specific
point in time.
Rationale: Prevalence = all existing cases ÷ population × multiplier. Incidence measures only new
cases. The "bathtub model" helps distinguish: incidence is water flowing in, prevalence is the
water level.
5. A nurse is screening for tuberculosis at a homeless shelter. Which level of prevention does
this activity represent?
A. Primary prevention
B. Secondary prevention
C. Tertiary prevention
D. Quaternary prevention
Correct Answer: B. Secondary prevention involves early detection and prompt treatment of
disease through screening, case finding, and diagnostic testing.
