NR 503 / NR503 Midterm Exam Actual Exam 2026 |
Population Health Epidemiology & Biostatistics |
Questions with Verified Answers | 100% Correct |
Pass Guaranteed
SECTION 1: Epidemiological Concepts & Measures
Q1: In a population of 5,000 adults, 150 individuals were newly diagnosed with type 2
diabetes mellitus in 2025. At the start of 2025, there were 300 existing cases. Which of
the following best describes the 150 newly diagnosed cases?
A. Point prevalence
B. Incidence
C. Period prevalence
D. Cumulative prevalence
Correct Answer: B
Rationale: Incidence measures the number of new cases occurring in a population at
risk during a specified time period (150 new cases). Point prevalence (A) would count
all existing cases at a single point in time (300 cases). Period prevalence would count
all cases existing during a time interval. Cumulative prevalence (D) is not a standard
epidemiological term—this describes cumulative incidence, which is a proportion.
Q2: During a catered wedding reception, 80 guests developed gastroenteritis within 48
hours. In total, 200 guests attended the reception. What is the attack rate?
A. 40 per 1,000 population
B. 40%
C. 0.4 per 100,000 population
D. Cannot be calculated from the data provided
Correct Answer: B
Rationale: Attack rate = (Number of cases / Total population at risk) × 100. Here, 80
cases ÷ 200 attendees = 0.40 × 100 = 40%. Option A incorrectly reports as a rate per
, 1,000 rather than a percentage. Option C uses an inappropriate denominator for this
scenario. The data is sufficient to calculate (D is incorrect).
Q3: Which component of the "chain of infection" represents a susceptible adult who has
not received an annual influenza vaccination?
A. Portal of exit
B. Susceptible host
C. Mode of transmission
D. Infectious agent
Correct Answer: B
Rationale: A susceptible host (B) is an individual lacking immunity to resist infection.
The portal of exit (A) is how the pathogen leaves the reservoir. Mode of transmission (C)
is the mechanism of spread (e.g., airborne). Infectious agent (D) is the pathogen itself.
The unvaccinated adult's susceptibility makes them the host in the chain.
Q4: A county health department reports that 8.5% of adults aged 18-65 currently have a
diagnosis of major depression based on a survey conducted January 1, 2026. This
measure is best described as:
A. Cumulative incidence
B. Point prevalence
C. Period prevalence
D. Lifetime prevalence
Correct Answer: B
Rationale: Point prevalence measures the proportion of a population with a condition at
a specific point in time (January 1, 2026). Cumulative incidence (A) would measure new
cases over time. Period prevalence (C) would measure cases across a longer interval
(e.g., entire year). Lifetime prevalence (D) would measure if individuals ever had
depression.
Population Health Epidemiology & Biostatistics |
Questions with Verified Answers | 100% Correct |
Pass Guaranteed
SECTION 1: Epidemiological Concepts & Measures
Q1: In a population of 5,000 adults, 150 individuals were newly diagnosed with type 2
diabetes mellitus in 2025. At the start of 2025, there were 300 existing cases. Which of
the following best describes the 150 newly diagnosed cases?
A. Point prevalence
B. Incidence
C. Period prevalence
D. Cumulative prevalence
Correct Answer: B
Rationale: Incidence measures the number of new cases occurring in a population at
risk during a specified time period (150 new cases). Point prevalence (A) would count
all existing cases at a single point in time (300 cases). Period prevalence would count
all cases existing during a time interval. Cumulative prevalence (D) is not a standard
epidemiological term—this describes cumulative incidence, which is a proportion.
Q2: During a catered wedding reception, 80 guests developed gastroenteritis within 48
hours. In total, 200 guests attended the reception. What is the attack rate?
A. 40 per 1,000 population
B. 40%
C. 0.4 per 100,000 population
D. Cannot be calculated from the data provided
Correct Answer: B
Rationale: Attack rate = (Number of cases / Total population at risk) × 100. Here, 80
cases ÷ 200 attendees = 0.40 × 100 = 40%. Option A incorrectly reports as a rate per
, 1,000 rather than a percentage. Option C uses an inappropriate denominator for this
scenario. The data is sufficient to calculate (D is incorrect).
Q3: Which component of the "chain of infection" represents a susceptible adult who has
not received an annual influenza vaccination?
A. Portal of exit
B. Susceptible host
C. Mode of transmission
D. Infectious agent
Correct Answer: B
Rationale: A susceptible host (B) is an individual lacking immunity to resist infection.
The portal of exit (A) is how the pathogen leaves the reservoir. Mode of transmission (C)
is the mechanism of spread (e.g., airborne). Infectious agent (D) is the pathogen itself.
The unvaccinated adult's susceptibility makes them the host in the chain.
Q4: A county health department reports that 8.5% of adults aged 18-65 currently have a
diagnosis of major depression based on a survey conducted January 1, 2026. This
measure is best described as:
A. Cumulative incidence
B. Point prevalence
C. Period prevalence
D. Lifetime prevalence
Correct Answer: B
Rationale: Point prevalence measures the proportion of a population with a condition at
a specific point in time (January 1, 2026). Cumulative incidence (A) would measure new
cases over time. Period prevalence (C) would measure cases across a longer interval
(e.g., entire year). Lifetime prevalence (D) would measure if individuals ever had
depression.
