NR 503
MID-TERM EXAM
Population Health, Epidemiology, & Statistical
Principles
Questions And Answers Plus Rationales 2026
Instant Pdf Download
CHAMBERLAIN
This exam consists of 100 NCLEX-style multiple-
choice questions, each with one correct Answer
and a detailed rationale.
,1. A community health nurse is calculating the number of new cases
of diabetes diagnosed in a county over the past year, divided by the
total population at risk during the same period. Which measure is
the nurse calculating?
A. Point prevalence
B. Period prevalence
C. Cumulative incidence
D. Incidence rate
Answer: C. Cumulative incidence
Rationale: Cumulative incidence is the number of new cases of a disease
occurring in a population at risk over a specified time period, divided by
the total population at risk at the beginning of the period. Point
prevalence measures existing cases at a single point in time. Period
prevalence measures existing cases over a period. Incidence rate includes
person-time in the denominator.
2. A researcher finds that the sensitivity of a new screening test for
breast cancer is 85%. This means:
A. 85% of people without breast cancer will test negative.
B. 85% of people with breast cancer will test positive.
C. 15% of people with breast cancer will test negative.
D. Both B and C.
,Answer: D. Both B and C.
Rationale: Sensitivity is the proportion of true positives correctly
identified (85% of those with disease test positive). The false negative
rate is 1 – sensitivity = 15%. Specificity refers to those without disease
testing negative.
3. In a cohort study examining the relationship between smoking
and lung cancer, the investigator finds a relative risk (RR) of 4.5.
Which interpretation is correct?
A. Smokers have 4.5 times the risk of lung cancer compared to non-
smokers.
B. Smokers have a 4.5% increased risk of lung cancer compared to non-
smokers.
C. The attributable risk among smokers is 4.5%.
D. There is no association between smoking and lung cancer.
Answer: A. Smokers have 4.5 times the risk of lung cancer compared to
non-smokers.
Rationale: Relative risk is a ratio of the incidence in the exposed group
to the incidence in the unexposed group. RR = 4.5 means the exposed
group has 4.5 times the risk. An RR of 1 indicates no association.
, 4. A public health nurse is reviewing the results of a tuberculosis
screening program. The test has a specificity of 99%. Which
statement best reflects the meaning of this value?
A. 99% of those with TB will test positive.
B. 99% of those without TB will test negative.
C. 1% of those with TB will test negative.
D. The test has a high false positive rate.
Answer: B. 99% of those without TB will test negative.
Rationale: Specificity is the ability of a test to correctly identify those
without the disease (true negative rate). High specificity means few false
positives. Sensitivity refers to true positives.
5. Which study design is considered the "gold standard" for
establishing causality in epidemiologic research?
A. Cross-sectional study
B. Case-control study
C. Randomized controlled trial (RCT)
D. Ecological study
Answer: C. Randomized controlled trial (RCT)
Rationale: RCTs randomly assign subjects to exposure or control groups,
minimizing bias and confounding, allowing for the strongest causal
MID-TERM EXAM
Population Health, Epidemiology, & Statistical
Principles
Questions And Answers Plus Rationales 2026
Instant Pdf Download
CHAMBERLAIN
This exam consists of 100 NCLEX-style multiple-
choice questions, each with one correct Answer
and a detailed rationale.
,1. A community health nurse is calculating the number of new cases
of diabetes diagnosed in a county over the past year, divided by the
total population at risk during the same period. Which measure is
the nurse calculating?
A. Point prevalence
B. Period prevalence
C. Cumulative incidence
D. Incidence rate
Answer: C. Cumulative incidence
Rationale: Cumulative incidence is the number of new cases of a disease
occurring in a population at risk over a specified time period, divided by
the total population at risk at the beginning of the period. Point
prevalence measures existing cases at a single point in time. Period
prevalence measures existing cases over a period. Incidence rate includes
person-time in the denominator.
2. A researcher finds that the sensitivity of a new screening test for
breast cancer is 85%. This means:
A. 85% of people without breast cancer will test negative.
B. 85% of people with breast cancer will test positive.
C. 15% of people with breast cancer will test negative.
D. Both B and C.
,Answer: D. Both B and C.
Rationale: Sensitivity is the proportion of true positives correctly
identified (85% of those with disease test positive). The false negative
rate is 1 – sensitivity = 15%. Specificity refers to those without disease
testing negative.
3. In a cohort study examining the relationship between smoking
and lung cancer, the investigator finds a relative risk (RR) of 4.5.
Which interpretation is correct?
A. Smokers have 4.5 times the risk of lung cancer compared to non-
smokers.
B. Smokers have a 4.5% increased risk of lung cancer compared to non-
smokers.
C. The attributable risk among smokers is 4.5%.
D. There is no association between smoking and lung cancer.
Answer: A. Smokers have 4.5 times the risk of lung cancer compared to
non-smokers.
Rationale: Relative risk is a ratio of the incidence in the exposed group
to the incidence in the unexposed group. RR = 4.5 means the exposed
group has 4.5 times the risk. An RR of 1 indicates no association.
, 4. A public health nurse is reviewing the results of a tuberculosis
screening program. The test has a specificity of 99%. Which
statement best reflects the meaning of this value?
A. 99% of those with TB will test positive.
B. 99% of those without TB will test negative.
C. 1% of those with TB will test negative.
D. The test has a high false positive rate.
Answer: B. 99% of those without TB will test negative.
Rationale: Specificity is the ability of a test to correctly identify those
without the disease (true negative rate). High specificity means few false
positives. Sensitivity refers to true positives.
5. Which study design is considered the "gold standard" for
establishing causality in epidemiologic research?
A. Cross-sectional study
B. Case-control study
C. Randomized controlled trial (RCT)
D. Ecological study
Answer: C. Randomized controlled trial (RCT)
Rationale: RCTs randomly assign subjects to exposure or control groups,
minimizing bias and confounding, allowing for the strongest causal
