NSG 550 Exam 1 Diagnostic Reasoning (2026/2027)
PDF | Nursing | Wilkes University, Exams of Nursing
Section 1: Foundations of Diagnostic Reasoning (Q1–20)
1. A 45-year-old presents with chest pain. Using the hypothetico-deductive model,
what is the first step?
A) Order an ECG
B) Generate an initial hypothesis list
C) Perform a complete physical exam
D) Review past medical records
Answer: B
Rationale: The hypothetico-deductive model begins with early hypothesis
generation from limited data, then testing through further questions/exam.
2. Which heuristic describes the tendency to judge likelihood based on how easily
examples come to mind?
A) Anchoring
B) Availability
C) Representativeness
D) Confirmation bias
Answer: B
Rationale: Availability heuristic – recent or memorable cases (e.g., last patient with
MI) skew probability estimates.
3. A test with 95% sensitivity means:
A) 95% of people without disease test negative
B) 5% of people with disease test negative
C) 95% of positive tests are true positives
D) The test is highly specific
Answer: B
Rationale: Sensitivity = true positive rate. 95% sensitive means 5% false negatives.
4. Pre-test probability is best derived from:
A) The test’s cost
B) Clinical judgment and epidemiology
,C) Patient insurance status
D) Laboratory reference ranges
Answer: B
Rationale: Pre-test probability is estimated from patient risk factors, symptoms,
and disease prevalence.
5. You suspect DVT. Which clinical decision rule is most validated?
A) CURB-65
B) Wells Score
C) CHA₂DS₂-VASc
D) HEART Score
Answer: B
Rationale: Wells Score for DVT combines risk factors, clinical signs, and
alternative diagnoses.
6. A clinician ignores new information that contradicts their initial diagnosis. This
is:
A) Ascertainment bias
B) Confirmation bias
C) Framing effect
D) Outcome bias
Answer: B
Rationale: Confirmation bias – seeking or favoring info that confirms one’s
hypothesis.
7. Which of the following increases post-test probability the most?
A) High sensitivity test, negative
B) High specificity test, positive
C) Low sensitivity test, positive
D) Low specificity test, negative
Answer: B
Rationale: SpPIN – a highly Specific test, when Positive, rules IN disease.
8. A 70-year-old with fall and leg pain. X-ray negative. You still suspect fracture.
Next step?
A) Discharge with NSAIDs
B) MRI
,C) Bone scan
D) Repeat X-ray in 2 weeks
Answer: B
Rationale: Occult hip fracture may be X-ray negative; MRI is gold standard.
9. LR+ of 10 means:
A) Post-test odds increase 10-fold
B) Post-test probability decreases 10%
C) Test is useless
D) Specificity is 10%
Answer: A
Rationale: Likelihood ratio >10 strongly increases probability of disease.
10. LR- of 0.1 means:
A) Disease is very likely
B) Disease is very unlikely
C) Test is 90% sensitive
D) Test is 90% specific
Answer: B
Rationale: LR- <0.1 greatly decreases disease probability (rule out).
11. A 30-year-old with sore throat. Centor criteria include all EXCEPT:
A) Fever
B) Tonsillar exudate
C) Cough
D) Tender anterior cervical nodes
Answer: C
Rationale: Centor criteria: fever, exudate, nodes, absence of cough.
12. Pre-test probability of pulmonary embolism is 30%. CTPA has 90% sensitivity,
95% specificity. Positive test yields post-test probability of:
A) 30%
B) 88%
C) 95%
D) 60%
Answer: B
Rationale: Bayes: PPV = (0.9×0.3)/(0.27+0.035)=0.27/0.305=88.5%.
, 13. The most common cognitive error in diagnosis is:
A) Overconfidence
B) Premature closure
C) Gender bias
D) Base rate neglect
Answer: B
Rationale: Premature closure – stopping search too early – is the most frequent.
14. A 55-year-old smoker with hemoptysis. Initial imaging of choice?
A) Chest X-ray
B) CT chest
C) MRI
D) PET scan
Answer: A
Rationale: Chest X-ray is first-line; CT if abnormal or high suspicion.
15. A test’s negative predictive value (NPV) is 98%. This means:
A) 2% false positives
B) 2% false negatives
C) 98% of negative tests are true negatives
D) 98% of positive tests are true positives
Answer: C
Rationale: NPV = proportion of negatives that are truly disease-free.
16. Which is NOT a component of the Ottawa Ankle Rules?
A) Inability to bear weight immediately after injury
B) Bone tenderness at lateral malleolus
C) Age >65
D) Bone tenderness at navicular
Answer: C
Rationale: Ottawa Ankle Rules: malleolar zone tenderness, navicular/5th
metatarsal tenderness, inability to bear weight.
17. A patient with dyspnea and unilateral leg swelling. Most likely diagnosis?
A) COPD
B) Pulmonary embolism
PDF | Nursing | Wilkes University, Exams of Nursing
Section 1: Foundations of Diagnostic Reasoning (Q1–20)
1. A 45-year-old presents with chest pain. Using the hypothetico-deductive model,
what is the first step?
A) Order an ECG
B) Generate an initial hypothesis list
C) Perform a complete physical exam
D) Review past medical records
Answer: B
Rationale: The hypothetico-deductive model begins with early hypothesis
generation from limited data, then testing through further questions/exam.
2. Which heuristic describes the tendency to judge likelihood based on how easily
examples come to mind?
A) Anchoring
B) Availability
C) Representativeness
D) Confirmation bias
Answer: B
Rationale: Availability heuristic – recent or memorable cases (e.g., last patient with
MI) skew probability estimates.
3. A test with 95% sensitivity means:
A) 95% of people without disease test negative
B) 5% of people with disease test negative
C) 95% of positive tests are true positives
D) The test is highly specific
Answer: B
Rationale: Sensitivity = true positive rate. 95% sensitive means 5% false negatives.
4. Pre-test probability is best derived from:
A) The test’s cost
B) Clinical judgment and epidemiology
,C) Patient insurance status
D) Laboratory reference ranges
Answer: B
Rationale: Pre-test probability is estimated from patient risk factors, symptoms,
and disease prevalence.
5. You suspect DVT. Which clinical decision rule is most validated?
A) CURB-65
B) Wells Score
C) CHA₂DS₂-VASc
D) HEART Score
Answer: B
Rationale: Wells Score for DVT combines risk factors, clinical signs, and
alternative diagnoses.
6. A clinician ignores new information that contradicts their initial diagnosis. This
is:
A) Ascertainment bias
B) Confirmation bias
C) Framing effect
D) Outcome bias
Answer: B
Rationale: Confirmation bias – seeking or favoring info that confirms one’s
hypothesis.
7. Which of the following increases post-test probability the most?
A) High sensitivity test, negative
B) High specificity test, positive
C) Low sensitivity test, positive
D) Low specificity test, negative
Answer: B
Rationale: SpPIN – a highly Specific test, when Positive, rules IN disease.
8. A 70-year-old with fall and leg pain. X-ray negative. You still suspect fracture.
Next step?
A) Discharge with NSAIDs
B) MRI
,C) Bone scan
D) Repeat X-ray in 2 weeks
Answer: B
Rationale: Occult hip fracture may be X-ray negative; MRI is gold standard.
9. LR+ of 10 means:
A) Post-test odds increase 10-fold
B) Post-test probability decreases 10%
C) Test is useless
D) Specificity is 10%
Answer: A
Rationale: Likelihood ratio >10 strongly increases probability of disease.
10. LR- of 0.1 means:
A) Disease is very likely
B) Disease is very unlikely
C) Test is 90% sensitive
D) Test is 90% specific
Answer: B
Rationale: LR- <0.1 greatly decreases disease probability (rule out).
11. A 30-year-old with sore throat. Centor criteria include all EXCEPT:
A) Fever
B) Tonsillar exudate
C) Cough
D) Tender anterior cervical nodes
Answer: C
Rationale: Centor criteria: fever, exudate, nodes, absence of cough.
12. Pre-test probability of pulmonary embolism is 30%. CTPA has 90% sensitivity,
95% specificity. Positive test yields post-test probability of:
A) 30%
B) 88%
C) 95%
D) 60%
Answer: B
Rationale: Bayes: PPV = (0.9×0.3)/(0.27+0.035)=0.27/0.305=88.5%.
, 13. The most common cognitive error in diagnosis is:
A) Overconfidence
B) Premature closure
C) Gender bias
D) Base rate neglect
Answer: B
Rationale: Premature closure – stopping search too early – is the most frequent.
14. A 55-year-old smoker with hemoptysis. Initial imaging of choice?
A) Chest X-ray
B) CT chest
C) MRI
D) PET scan
Answer: A
Rationale: Chest X-ray is first-line; CT if abnormal or high suspicion.
15. A test’s negative predictive value (NPV) is 98%. This means:
A) 2% false positives
B) 2% false negatives
C) 98% of negative tests are true negatives
D) 98% of positive tests are true positives
Answer: C
Rationale: NPV = proportion of negatives that are truly disease-free.
16. Which is NOT a component of the Ottawa Ankle Rules?
A) Inability to bear weight immediately after injury
B) Bone tenderness at lateral malleolus
C) Age >65
D) Bone tenderness at navicular
Answer: C
Rationale: Ottawa Ankle Rules: malleolar zone tenderness, navicular/5th
metatarsal tenderness, inability to bear weight.
17. A patient with dyspnea and unilateral leg swelling. Most likely diagnosis?
A) COPD
B) Pulmonary embolism
