NR 569 Midterm Exam - Differential Diagnosis in Acute Care Practicum | Chamberlain University
NR569 / NR 569 Midterm Exam (Latest
Update)
Differential Diagnosis in Acute Care Practicum | Weeks 1-4 | Questions and Verified Answers |
100% Correct
Chamberlain University - College of Nursing
2026/2027 Academic Year | Acute Care Nurse Practitioner Practicum
Total Questions Cognitive Levels Question Style
25% Recall / 50% Application / 25% 75% Scenario / 15% Recall / 10%
75 Multiple Choice
Analysis Clinical Judgment
Instructions: Select the single best answer for each question. Each question provides a rationale explaining the
correct response and why alternative options are incorrect, integrating Chamberlain University NR 569 Weeks
1-4 differential diagnosis concepts, clinical reasoning frameworks (SNAPPS, OLDCARTS), diagnostic accuracy
principles, and evidence-based acute care practice.
Section 1: Clinical Reasoning and Diagnostic Frameworks (Q1-Q15)
SNAPPS, OLDCARTS, diagnostic accuracy (sensitivity, specificity, PPV, NPV, likelihood ratios, SPIN/SNOUT),
pretest/posttest probability, pertinent positives/negatives, and skilled interviewing.
Q1: A nurse practitioner student is presenting a complex case to their preceptor using the
SNAPPS framework. After summarizing the history and physical, the student narrows the
differential to three possibilities and then begins to compare and contrast the clinical findings of
each. Which component of SNAPPS is the student demonstrating?
A. Probe
B. Analyze [CORRECT]
C. Plan
D. Select
Correct Answer: B
Rationale: The SNAPPS mnemonic stands for Summarize, Narrow, Analyze, Probe, Plan, and Select. The
"Analyze" step involves comparing and contrasting the narrowed differential diagnoses by exploring the
pertinent positives and negatives that support or refute each possibility. This differs from "Probe" (asking the
preceptor questions about uncertainties), "Plan" (proposing the diagnostic and therapeutic management plan),
and "Select" (choosing the most likely diagnosis with case reflection). SNAPPS is widely endorsed in
Chamberlain NR 569 as a learner-centered case presentation model that promotes clinical reasoning.
Q2: When taking a history from a patient presenting with chest pain, the nurse practitioner uses
the OLDCARTS mnemonic. Which of the following correctly identifies the components assessed
by OLDCARTS?
A. Onset, Location/radiation, Duration, Character, Aggravating factors, Relieving factors,
Timing, Severity [CORRECT]
Chamberlain University | Weeks 1-4 Content | Latest 2026/2027 Update Page 1
,NR 569 Midterm Exam - Differential Diagnosis in Acute Care Practicum | Chamberlain University
B. Onset, Location, Description, Course, Associated symptoms, Risk factors, Treatment, Status
C. Origin, Length, Duration, Character, Aggravating, Resolution, Timing, Severity
D. Onset, Lymph nodes, Duration, Character, Aggravating, Relieving, Treatment, Severity
Correct Answer: A
Rationale: OLDCARTS expands to Onset, Location/Radiation, Duration, Character, Aggravating factors,
Relieving factors, Timing, and Severity. It is a comprehensive symptom analysis framework taught in
Chamberlain NR 569 for the HPI. The other options either substitute incorrect terms (Description vs.
Character, Course vs. Duration) or include irrelevant elements (lymph nodes, treatment). Using OLDCARTS
ensures a complete, chronologic HPI that supports accurate differential diagnosis.
Q3: A diagnostic test has a sensitivity of 95% for detecting pulmonary embolism. Which principle
best describes the clinical application of this finding?
A. SpPin: A positive test rules IN the disease
B. SnNout: A negative test effectively rules OUT the disease [CORRECT]
C. A positive test confirms the diagnosis
D. The test has high specificity for pulmonary embolism
Correct Answer: B
Rationale: Sensitivity is the probability of a positive test when disease is present. The mnemonic "SnNout"
indicates that a test with high Sensitivity, when Negative, rules OUT the disease. This is why D-dimer (high
sensitivity, low specificity) is used to exclude PE when negative in low-risk patients. "SpPin" (high Specificity,
positive test rules IN) applies to tests like CT angiography. Sensitivity and specificity are independent test
properties, so high sensitivity does not imply high specificity.
Q4: A nurse practitioner is evaluating a new rapid test for influenza with a specificity of 98%. A
patient tests positive. Which statement best describes the clinical significance of this result?
A. The patient definitely has influenza
B. The probability that the patient truly has influenza depends on the pretest probability and
positive likelihood ratio [CORRECT]
C. The test has ruled out influenza
D. The test result is invalid without knowing the sensitivity
Correct Answer: B
Rationale: Specificity is the probability of a negative test in the absence of disease. While high specificity
(SpPin: a positive test rules IN the disease) supports the diagnosis, the posttest probability also depends on
pretest probability (prevalence in the population) and the positive likelihood ratio (LR+ = sensitivity / (1 -
specificity)). A positive highly specific test markedly raises the odds of disease, but no test result is "definitive"
without clinical context. The NP must apply Bayesian reasoning rather than rely on the test alone.
Q5: A patient presents with acute dyspnea, and the NP calculates a Wells score of 1.5 (low
probability of PE). The PERC rule is applied and all 8 criteria are negative. What is the most
appropriate next step?
A. Obtain a D-dimer to further reduce probability
B. No further testing for PE is required; PE is ruled out clinically [CORRECT]
C. Order a CT pulmonary angiogram
D. Start anticoagulation empirically
Chamberlain University | Weeks 1-4 Content | Latest 2026/2027 Update Page 2
, NR 569 Midterm Exam - Differential Diagnosis in Acute Care Practicum | Chamberlain University
Correct Answer: B
Rationale: In patients with low pretest probability of PE (Wells < 2) and all PERC criteria negative, the
probability of PE is so low (< 1.8%) that no further diagnostic testing is needed. The PERC rule (Pulmonary
Embolism Rule-out Criteria) prevents unnecessary D-dimer testing, radiation exposure, and anticoagulation in
very low-risk patients. Ordering a D-dimer in this scenario would yield a high false-positive rate. CTPA and
empiric anticoagulation are inappropriate when PE is effectively ruled out.
Q6: A test has a positive likelihood ratio (LR+) of 10. How should this be interpreted in clinical
practice?
A. A positive test result has no meaningful impact on disease probability
B. A positive test result markedly increases the probability of disease [CORRECT]
C. A negative test result rules out the disease
D. The test has low diagnostic accuracy
Correct Answer: B
Rationale: The positive likelihood ratio (LR+) = sensitivity / (1 - specificity). An LR+ of 10 indicates that a
positive test result is 10 times more likely to occur in a patient with the disease than in one without. LRs > 10
generate large, conclusive shifts from pretest to posttest probability. The NP applies this by multiplying pretest
odds by the LR+ to obtain posttest odds. Unlike sensitivity/specificity, LRs are independent of disease
prevalence and are the preferred tool for clinical Bayesian reasoning.
Q7: A patient has a pretest probability of disease of 20% (0.20). After a positive test with an LR+
of 5, what is the most accurate statement regarding posttest probability?
A. Posttest probability cannot be calculated without sensitivity
B. Posttest probability will be higher than 20% but requires converting pretest probability to
odds first, then multiplying by LR+ [CORRECT]
C. Posttest probability is exactly 100%
D. Posttest probability remains 20%
Correct Answer: B
Rationale: To calculate posttest probability, convert pretest probability (0.20) to pretest odds (0.20/0.80 =
0.25), multiply by LR+ (0.25 x 5 = 1.25 posttest odds), then convert back to probability (1.25/2.25 = 0.556, or
~56%). The NP cannot directly multiply probability by LR+; the conversion to odds is mandatory. This
Bayesian approach is emphasized in NR 569 to teach quantitative diagnostic reasoning rather than relying on
intuition.
Q8: When constructing a differential diagnosis for a patient with acute dyspnea, the NP lists
pneumonia, heart failure, and pulmonary embolism. The NP documents "no calf swelling, no
recent surgery, no hemoptysis" in the chart. These findings represent which of the following?
A. Pertinent positives
B. Pertinent negatives [CORRECT]
C. Red flag findings
D. Subjective objective data
Correct Answer: B
Rationale: Pertinent negatives are signs or symptoms expected to be present with a particular diagnosis but are
absent, thereby decreasing the likelihood of that diagnosis. In this case, the absence of calf swelling, recent
Chamberlain University | Weeks 1-4 Content | Latest 2026/2027 Update Page 3
NR569 / NR 569 Midterm Exam (Latest
Update)
Differential Diagnosis in Acute Care Practicum | Weeks 1-4 | Questions and Verified Answers |
100% Correct
Chamberlain University - College of Nursing
2026/2027 Academic Year | Acute Care Nurse Practitioner Practicum
Total Questions Cognitive Levels Question Style
25% Recall / 50% Application / 25% 75% Scenario / 15% Recall / 10%
75 Multiple Choice
Analysis Clinical Judgment
Instructions: Select the single best answer for each question. Each question provides a rationale explaining the
correct response and why alternative options are incorrect, integrating Chamberlain University NR 569 Weeks
1-4 differential diagnosis concepts, clinical reasoning frameworks (SNAPPS, OLDCARTS), diagnostic accuracy
principles, and evidence-based acute care practice.
Section 1: Clinical Reasoning and Diagnostic Frameworks (Q1-Q15)
SNAPPS, OLDCARTS, diagnostic accuracy (sensitivity, specificity, PPV, NPV, likelihood ratios, SPIN/SNOUT),
pretest/posttest probability, pertinent positives/negatives, and skilled interviewing.
Q1: A nurse practitioner student is presenting a complex case to their preceptor using the
SNAPPS framework. After summarizing the history and physical, the student narrows the
differential to three possibilities and then begins to compare and contrast the clinical findings of
each. Which component of SNAPPS is the student demonstrating?
A. Probe
B. Analyze [CORRECT]
C. Plan
D. Select
Correct Answer: B
Rationale: The SNAPPS mnemonic stands for Summarize, Narrow, Analyze, Probe, Plan, and Select. The
"Analyze" step involves comparing and contrasting the narrowed differential diagnoses by exploring the
pertinent positives and negatives that support or refute each possibility. This differs from "Probe" (asking the
preceptor questions about uncertainties), "Plan" (proposing the diagnostic and therapeutic management plan),
and "Select" (choosing the most likely diagnosis with case reflection). SNAPPS is widely endorsed in
Chamberlain NR 569 as a learner-centered case presentation model that promotes clinical reasoning.
Q2: When taking a history from a patient presenting with chest pain, the nurse practitioner uses
the OLDCARTS mnemonic. Which of the following correctly identifies the components assessed
by OLDCARTS?
A. Onset, Location/radiation, Duration, Character, Aggravating factors, Relieving factors,
Timing, Severity [CORRECT]
Chamberlain University | Weeks 1-4 Content | Latest 2026/2027 Update Page 1
,NR 569 Midterm Exam - Differential Diagnosis in Acute Care Practicum | Chamberlain University
B. Onset, Location, Description, Course, Associated symptoms, Risk factors, Treatment, Status
C. Origin, Length, Duration, Character, Aggravating, Resolution, Timing, Severity
D. Onset, Lymph nodes, Duration, Character, Aggravating, Relieving, Treatment, Severity
Correct Answer: A
Rationale: OLDCARTS expands to Onset, Location/Radiation, Duration, Character, Aggravating factors,
Relieving factors, Timing, and Severity. It is a comprehensive symptom analysis framework taught in
Chamberlain NR 569 for the HPI. The other options either substitute incorrect terms (Description vs.
Character, Course vs. Duration) or include irrelevant elements (lymph nodes, treatment). Using OLDCARTS
ensures a complete, chronologic HPI that supports accurate differential diagnosis.
Q3: A diagnostic test has a sensitivity of 95% for detecting pulmonary embolism. Which principle
best describes the clinical application of this finding?
A. SpPin: A positive test rules IN the disease
B. SnNout: A negative test effectively rules OUT the disease [CORRECT]
C. A positive test confirms the diagnosis
D. The test has high specificity for pulmonary embolism
Correct Answer: B
Rationale: Sensitivity is the probability of a positive test when disease is present. The mnemonic "SnNout"
indicates that a test with high Sensitivity, when Negative, rules OUT the disease. This is why D-dimer (high
sensitivity, low specificity) is used to exclude PE when negative in low-risk patients. "SpPin" (high Specificity,
positive test rules IN) applies to tests like CT angiography. Sensitivity and specificity are independent test
properties, so high sensitivity does not imply high specificity.
Q4: A nurse practitioner is evaluating a new rapid test for influenza with a specificity of 98%. A
patient tests positive. Which statement best describes the clinical significance of this result?
A. The patient definitely has influenza
B. The probability that the patient truly has influenza depends on the pretest probability and
positive likelihood ratio [CORRECT]
C. The test has ruled out influenza
D. The test result is invalid without knowing the sensitivity
Correct Answer: B
Rationale: Specificity is the probability of a negative test in the absence of disease. While high specificity
(SpPin: a positive test rules IN the disease) supports the diagnosis, the posttest probability also depends on
pretest probability (prevalence in the population) and the positive likelihood ratio (LR+ = sensitivity / (1 -
specificity)). A positive highly specific test markedly raises the odds of disease, but no test result is "definitive"
without clinical context. The NP must apply Bayesian reasoning rather than rely on the test alone.
Q5: A patient presents with acute dyspnea, and the NP calculates a Wells score of 1.5 (low
probability of PE). The PERC rule is applied and all 8 criteria are negative. What is the most
appropriate next step?
A. Obtain a D-dimer to further reduce probability
B. No further testing for PE is required; PE is ruled out clinically [CORRECT]
C. Order a CT pulmonary angiogram
D. Start anticoagulation empirically
Chamberlain University | Weeks 1-4 Content | Latest 2026/2027 Update Page 2
, NR 569 Midterm Exam - Differential Diagnosis in Acute Care Practicum | Chamberlain University
Correct Answer: B
Rationale: In patients with low pretest probability of PE (Wells < 2) and all PERC criteria negative, the
probability of PE is so low (< 1.8%) that no further diagnostic testing is needed. The PERC rule (Pulmonary
Embolism Rule-out Criteria) prevents unnecessary D-dimer testing, radiation exposure, and anticoagulation in
very low-risk patients. Ordering a D-dimer in this scenario would yield a high false-positive rate. CTPA and
empiric anticoagulation are inappropriate when PE is effectively ruled out.
Q6: A test has a positive likelihood ratio (LR+) of 10. How should this be interpreted in clinical
practice?
A. A positive test result has no meaningful impact on disease probability
B. A positive test result markedly increases the probability of disease [CORRECT]
C. A negative test result rules out the disease
D. The test has low diagnostic accuracy
Correct Answer: B
Rationale: The positive likelihood ratio (LR+) = sensitivity / (1 - specificity). An LR+ of 10 indicates that a
positive test result is 10 times more likely to occur in a patient with the disease than in one without. LRs > 10
generate large, conclusive shifts from pretest to posttest probability. The NP applies this by multiplying pretest
odds by the LR+ to obtain posttest odds. Unlike sensitivity/specificity, LRs are independent of disease
prevalence and are the preferred tool for clinical Bayesian reasoning.
Q7: A patient has a pretest probability of disease of 20% (0.20). After a positive test with an LR+
of 5, what is the most accurate statement regarding posttest probability?
A. Posttest probability cannot be calculated without sensitivity
B. Posttest probability will be higher than 20% but requires converting pretest probability to
odds first, then multiplying by LR+ [CORRECT]
C. Posttest probability is exactly 100%
D. Posttest probability remains 20%
Correct Answer: B
Rationale: To calculate posttest probability, convert pretest probability (0.20) to pretest odds (0.20/0.80 =
0.25), multiply by LR+ (0.25 x 5 = 1.25 posttest odds), then convert back to probability (1.25/2.25 = 0.556, or
~56%). The NP cannot directly multiply probability by LR+; the conversion to odds is mandatory. This
Bayesian approach is emphasized in NR 569 to teach quantitative diagnostic reasoning rather than relying on
intuition.
Q8: When constructing a differential diagnosis for a patient with acute dyspnea, the NP lists
pneumonia, heart failure, and pulmonary embolism. The NP documents "no calf swelling, no
recent surgery, no hemoptysis" in the chart. These findings represent which of the following?
A. Pertinent positives
B. Pertinent negatives [CORRECT]
C. Red flag findings
D. Subjective objective data
Correct Answer: B
Rationale: Pertinent negatives are signs or symptoms expected to be present with a particular diagnosis but are
absent, thereby decreasing the likelihood of that diagnosis. In this case, the absence of calf swelling, recent
Chamberlain University | Weeks 1-4 Content | Latest 2026/2027 Update Page 3
