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NR 503 WEEK 8 FINAL EXAM 2026/2027 | 100 Questions
& Answer Solutions | Epidemiology Population Health
EBP | Graded A | Pass Guaranteed
[Section 1: Epidemiological Foundations & Measures (Q1-15)]
Q1. A county health department reports that in 2026, there were 850 new cases of
type 2 diabetes diagnosed among 125,000 adults aged 45-64 years. What is the
incidence rate per 100,000 person-years?
A. 340 per 100,000 person-years B. 580 per 100,000 person-years C. 680 per 100,000
person-years [CORRECT] D. 850 per 100,000 person-years
Rationale: Incidence rate = (New cases / Population at risk) × multiplier = (850 /
125,000) × 100,000 = 680 per 100,000 person-years. This measures the occurrence of
new disease over a specified time period. Students often confuse incidence with
prevalence or forget to apply the multiplier correctly.
Correct Answer: C
Q2. A school nurse screens 2,000 students and finds 120 currently have asthma.
Which epidemiological measure describes this finding?
A. Incidence rate of 60 per 1,000 B. Point prevalence of 60 per 1,000 [CORRECT] C.
Period prevalence of 120 per 2,000 D. Cumulative incidence of 6%
Rationale: Point prevalence = (Existing cases at a specific point in time / Total
population) × multiplier = (,000) × 1,000 = 60 per 1,000. Prevalence includes
all existing cases (new + old) at one point in time. Incidence measures only new
cases; period prevalence covers a time interval; cumulative incidence requires a
defined population followed over time.
,2
Correct Answer: B
Q3. During a meningococcal outbreak on a college campus, 45 students developed
disease among 300 exposed residents. Eighteen students died. What is the case
fatality rate (CFR)?
A. 6% B. 15% C. 40% [CORRECT] D. 60%
Rationale: CFR = (Deaths from disease / Total cases of disease) × 100 = () ×
100 = 40%. CFR measures the severity of a disease among those diagnosed. Students
often incorrectly divide deaths by the total exposed population (18/300 = 6%), which
is the mortality rate, not CFR.
Correct Answer: C
Q4. In a city of 500,000 people, there were 2,500 total deaths in 2026. Of these, 750
were due to cardiovascular disease. What is the proportionate mortality from
cardiovascular disease?
A. 0.15% B. 1.5% C. 15% D. 30% [CORRECT]
Rationale: Proportionate mortality = (Deaths from specific cause / Total deaths from
all causes) × 100 = (,500) × 100 = 30%. This measures the proportion of all
deaths attributable to a specific cause. It differs from cause-specific mortality rate
(750/500,000), which measures risk in the total population.
Correct Answer: D
Q5. A 35-year-old dies in a motor vehicle accident. Using an age cutoff of 75 years
for YPLL calculation, how many years of potential life are lost?
A. 30 years B. 35 years C. 40 years [CORRECT] D. 75 years
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Rationale: YPLL = Age cutoff - Age at death = 75 - 35 = 40 years. YPLL gives greater
weight to deaths occurring at younger ages and is used to prioritize public health
interventions. Students sometimes incorrectly use the age at death as the YPLL or
confuse YPLL with life expectancy calculations.
Correct Answer: C
Q6. A prospective cohort study of 2,000 smokers and 3,000 non-smokers followed
for 10 years finds 120 lung cancers among smokers and 30 among non-smokers.
Constructing a 2×2 table, what is the relative risk (RR)?
A. 2.0 B. 4.0 C. 6.0 [CORRECT] D. 8.0
Rationale: RR = [a/(a+b)] / [c/(c+d)] = [120/2,000] / [30/3,000] = 0..01 = 6.0.
The 2×2 table is: a=120 (exposed, diseased), b=1,880 (exposed, not diseased), c=30
(unexposed, diseased), d=2,970 (unexposed, not diseased). Students often place cells
incorrectly or use odds ratio formula for RR.
Correct Answer: C
Q7. Using the same smoking cohort data (Q6), what is the attributable risk (AR)
among the exposed?
A. 0.01 B. 0.03 C. 0.05 [CORRECT] D. 0.06
Rationale: AR = Risk in exposed - Risk in unexposed = (120/2,000) - (30/3,000) =
0.06 - 0.01 = 0.05. AR represents the excess risk in the exposed group attributable to
the exposure. It is also called risk difference. Students often confuse AR with relative
risk or attributable risk percent.
Correct Answer: C
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Q8. A case-control study of 200 cases and 200 controls finds that 140 cases and 70
controls reported exposure to a suspected risk factor. What is the odds ratio (OR)?
A. 2.0 B. 3.0 C. 4.0 [CORRECT] D. 6.0
Rationale: OR = (a×d) / (b×c) = (140×130) / (60×70) = 18,,200 = 4.33 ≈ 4.0.
The 2×2 table: a=140 (cases exposed), b=60 (cases unexposed), c=70 (controls
exposed), d=130 (controls unexposed). Students often invert the formula or confuse
case-control cell placement with cohort studies.
Correct Answer: C
Q9. A rare disease affects 2% of the population. In a case-control study, the odds
ratio is calculated as 4.5. Under the rare disease assumption, what does the OR
approximate?
A. Prevalence ratio B. Relative risk [CORRECT] C. Attributable risk percent D.
Population attributable risk
Rationale: When disease prevalence is <10% (rare disease assumption), the odds
ratio closely approximates the relative risk because the number of cases is small
relative to the total population, making a ≈ a+b and c ≈ c+d. This is a critical
assumption that allows OR from case-control studies to be interpreted similarly to
RR. Students often forget this assumption and apply OR=RR universally.
Correct Answer: B
Q10. A clinical trial shows a new antihypertensive reduces stroke risk from 8% to 5%
over 5 years. What is the number needed to treat (NNT) to prevent one stroke?
A. 20 B. 33 [CORRECT] C. 50 D. 100
Rationale: NNT = 1 / Absolute Risk Reduction (ARR) = 1 / (0.08 - 0.05) = .03 =
33.3 ≈ 33. ARR = Control event rate - Treatment event rate. NNT represents how
many patients must be treated to prevent one adverse outcome. Students often
calculate NNH instead or use relative risk reduction incorrectly.
NR 503 WEEK 8 FINAL EXAM 2026/2027 | 100 Questions
& Answer Solutions | Epidemiology Population Health
EBP | Graded A | Pass Guaranteed
[Section 1: Epidemiological Foundations & Measures (Q1-15)]
Q1. A county health department reports that in 2026, there were 850 new cases of
type 2 diabetes diagnosed among 125,000 adults aged 45-64 years. What is the
incidence rate per 100,000 person-years?
A. 340 per 100,000 person-years B. 580 per 100,000 person-years C. 680 per 100,000
person-years [CORRECT] D. 850 per 100,000 person-years
Rationale: Incidence rate = (New cases / Population at risk) × multiplier = (850 /
125,000) × 100,000 = 680 per 100,000 person-years. This measures the occurrence of
new disease over a specified time period. Students often confuse incidence with
prevalence or forget to apply the multiplier correctly.
Correct Answer: C
Q2. A school nurse screens 2,000 students and finds 120 currently have asthma.
Which epidemiological measure describes this finding?
A. Incidence rate of 60 per 1,000 B. Point prevalence of 60 per 1,000 [CORRECT] C.
Period prevalence of 120 per 2,000 D. Cumulative incidence of 6%
Rationale: Point prevalence = (Existing cases at a specific point in time / Total
population) × multiplier = (,000) × 1,000 = 60 per 1,000. Prevalence includes
all existing cases (new + old) at one point in time. Incidence measures only new
cases; period prevalence covers a time interval; cumulative incidence requires a
defined population followed over time.
,2
Correct Answer: B
Q3. During a meningococcal outbreak on a college campus, 45 students developed
disease among 300 exposed residents. Eighteen students died. What is the case
fatality rate (CFR)?
A. 6% B. 15% C. 40% [CORRECT] D. 60%
Rationale: CFR = (Deaths from disease / Total cases of disease) × 100 = () ×
100 = 40%. CFR measures the severity of a disease among those diagnosed. Students
often incorrectly divide deaths by the total exposed population (18/300 = 6%), which
is the mortality rate, not CFR.
Correct Answer: C
Q4. In a city of 500,000 people, there were 2,500 total deaths in 2026. Of these, 750
were due to cardiovascular disease. What is the proportionate mortality from
cardiovascular disease?
A. 0.15% B. 1.5% C. 15% D. 30% [CORRECT]
Rationale: Proportionate mortality = (Deaths from specific cause / Total deaths from
all causes) × 100 = (,500) × 100 = 30%. This measures the proportion of all
deaths attributable to a specific cause. It differs from cause-specific mortality rate
(750/500,000), which measures risk in the total population.
Correct Answer: D
Q5. A 35-year-old dies in a motor vehicle accident. Using an age cutoff of 75 years
for YPLL calculation, how many years of potential life are lost?
A. 30 years B. 35 years C. 40 years [CORRECT] D. 75 years
,3
Rationale: YPLL = Age cutoff - Age at death = 75 - 35 = 40 years. YPLL gives greater
weight to deaths occurring at younger ages and is used to prioritize public health
interventions. Students sometimes incorrectly use the age at death as the YPLL or
confuse YPLL with life expectancy calculations.
Correct Answer: C
Q6. A prospective cohort study of 2,000 smokers and 3,000 non-smokers followed
for 10 years finds 120 lung cancers among smokers and 30 among non-smokers.
Constructing a 2×2 table, what is the relative risk (RR)?
A. 2.0 B. 4.0 C. 6.0 [CORRECT] D. 8.0
Rationale: RR = [a/(a+b)] / [c/(c+d)] = [120/2,000] / [30/3,000] = 0..01 = 6.0.
The 2×2 table is: a=120 (exposed, diseased), b=1,880 (exposed, not diseased), c=30
(unexposed, diseased), d=2,970 (unexposed, not diseased). Students often place cells
incorrectly or use odds ratio formula for RR.
Correct Answer: C
Q7. Using the same smoking cohort data (Q6), what is the attributable risk (AR)
among the exposed?
A. 0.01 B. 0.03 C. 0.05 [CORRECT] D. 0.06
Rationale: AR = Risk in exposed - Risk in unexposed = (120/2,000) - (30/3,000) =
0.06 - 0.01 = 0.05. AR represents the excess risk in the exposed group attributable to
the exposure. It is also called risk difference. Students often confuse AR with relative
risk or attributable risk percent.
Correct Answer: C
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Q8. A case-control study of 200 cases and 200 controls finds that 140 cases and 70
controls reported exposure to a suspected risk factor. What is the odds ratio (OR)?
A. 2.0 B. 3.0 C. 4.0 [CORRECT] D. 6.0
Rationale: OR = (a×d) / (b×c) = (140×130) / (60×70) = 18,,200 = 4.33 ≈ 4.0.
The 2×2 table: a=140 (cases exposed), b=60 (cases unexposed), c=70 (controls
exposed), d=130 (controls unexposed). Students often invert the formula or confuse
case-control cell placement with cohort studies.
Correct Answer: C
Q9. A rare disease affects 2% of the population. In a case-control study, the odds
ratio is calculated as 4.5. Under the rare disease assumption, what does the OR
approximate?
A. Prevalence ratio B. Relative risk [CORRECT] C. Attributable risk percent D.
Population attributable risk
Rationale: When disease prevalence is <10% (rare disease assumption), the odds
ratio closely approximates the relative risk because the number of cases is small
relative to the total population, making a ≈ a+b and c ≈ c+d. This is a critical
assumption that allows OR from case-control studies to be interpreted similarly to
RR. Students often forget this assumption and apply OR=RR universally.
Correct Answer: B
Q10. A clinical trial shows a new antihypertensive reduces stroke risk from 8% to 5%
over 5 years. What is the number needed to treat (NNT) to prevent one stroke?
A. 20 B. 33 [CORRECT] C. 50 D. 100
Rationale: NNT = 1 / Absolute Risk Reduction (ARR) = 1 / (0.08 - 0.05) = .03 =
33.3 ≈ 33. ARR = Control event rate - Treatment event rate. NNT represents how
many patients must be treated to prevent one adverse outcome. Students often
calculate NNH instead or use relative risk reduction incorrectly.
