NR 511: Differential Diagnosis and Primary
Care
Midterm Examination – Set A (Weeks 1–4)
Chamberlain University | 2026/2027
125 Questions with Expert Rationales
Section 1: Clinical Decision-Making and Diagnostic Reasoning
(Questions 1-20)
1. A 55-year-old male presents with a chief complaint of "fatigue." Which of
the following is the MOST appropriate initial step in the clinical reasoning
process?
A. Order a complete blood count
B. Perform a comprehensive physical examination
C. Obtain a detailed history, including onset, duration, and associated symptoms
D. Prescribe a multivitamin
Answer: C
Expert Rationale: The clinical reasoning process begins with a thorough history.
Fatigue has a broad differential diagnosis; the history guides the differential and
subsequent focused physical exam and testing.
2. The NP is using the differential diagnosis process for a patient with
abdominal pain. Which of the following represents the correct sequence?
A. Hypothesis generation → Data collection → Data interpretation → Problem
identification → Management
B. Data collection → Hypothesis generation → Data interpretation → Problem
identification → Management
C. Data collection → Data interpretation → Hypothesis generation → Problem
identification → Management
,D. Hypothesis generation → Data interpretation → Data collection → Problem
identification → Management
Answer: B
Expert Rationale: The correct sequence is data collection (history, physical) →
hypothesis generation (developing differential diagnoses) → data interpretation
(analyzing findings) → problem identification → management.
3. A 28-year-old female presents with acute-onset severe headache. Which of
the following historical features would be a "red flag" requiring immediate
evaluation?
A. Headache lasting 4 hours with nausea
B. Headache associated with menstruation
C. Sudden-onset "thunderclap" headache
D. Headache with mild photophobia
Answer: C
Expert Rationale: A sudden-onset "thunderclap" headache is a red flag that may
indicate subarachnoid hemorrhage. This requires immediate neuroimaging (non-
contrast CT) and possibly lumbar puncture.
4. Which of the following is an example of a pathognomonic sign in clinical
medicine?
A. Fever in pneumonia
B. Koplik spots in measles
C. Wheezing in asthma
D. Rash in chickenpox
Answer: B
Expert Rationale: Koplik spots (small white spots on the buccal mucosa) are
pathognomonic for measles (rubeola). Pathognomonic signs are uniquely
characteristic of a specific disease.
5. The NP understands that the "pretest probability" of a disease is influenced
by all of the following EXCEPT:
A. Prevalence of the disease in the population
B. Patient's age and gender
C. The cost of diagnostic testing
D. Clinical presentation and risk factors
Answer: C
Expert Rationale: Pretest probability is influenced by disease prevalence, patient
demographics, clinical presentation, and risk factors. Cost of testing does not affect
the probability of disease but may influence whether testing is pursued.
,6. A diagnostic test has a sensitivity of 90% and a specificity of 85%. A negative
result on this test is most useful for:
A. Ruling in the disease
B. Ruling out the disease
C. Confirming the diagnosis
D. Establishing prognosis
Answer: B
Expert Rationale: High sensitivity is useful for ruling out disease (SnNOut: high
Sensitivity, Negative result rules out). A negative result makes the diagnosis unlikely.
7. The NP is considering ordering a D-dimer test for a patient with suspected
deep vein thrombosis. The D-dimer has high sensitivity but low specificity. A
positive D-dimer in a low-risk patient indicates:
A. DVT is confirmed
B. Further testing (ultrasound) is needed
C. No further testing is needed
D. Anticoagulation should be started immediately
Answer: B
Expert Rationale: D-dimer has high sensitivity but low specificity. A positive
result is not diagnostic and requires confirmatory imaging (venous ultrasound) in
patients with suspected DVT.
8. A 45-year-old male presents with chest pain. The NP generates a differential
diagnosis that includes myocardial infarction, GERD, and musculoskeletal pain.
This process is called:
A. Bayesian analysis
B. Hypothesis generation
C. Test interpretation
D. Outcome assessment
Answer: B
Expert Rationale: Hypothesis generation is the process of developing a list of
potential diagnoses based on the initial data (history, physical). This list forms the
differential diagnosis.
9. The NP understands that the "number needed to treat" (NNT) for a
medication is 20. This means:
A. 20 patients need to be treated to prevent one adverse outcome
B. The medication costs $20 per dose
C. 20% of patients will experience an adverse effect
D. The medication is 20% effective
, Answer: A
Expert Rationale: NNT is the number of patients who need to be treated to
prevent one additional adverse outcome. A lower NNT indicates a more effective
treatment.
10. A 62-year-old male presents with a 3-month history of unintentional weight
loss and night sweats. These symptoms are classified as:
A. Local symptoms
B. Constitutional symptoms
C. Psychosomatic symptoms
D. Acute symptoms
Answer: B
Expert Rationale: Constitutional symptoms are systemic symptoms that affect
the entire body, including unintentional weight loss, fever, night sweats, and fatigue.
11. The NP is evaluating a patient with a chief complaint of "dizziness." The
patient describes a sensation of spinning. This is correctly termed:
A. Lightheadedness
B. Vertigo
C. Disequilibrium
D. Presyncope
Answer: B
Expert Rationale: Vertigo is the false sensation of movement, typically spinning
or rotational. It is important to distinguish vertigo from lightheadedness,
disequilibrium, and presyncope.
12. A 35-year-old female presents with fatigue. Which of the following
historical elements would be MOST concerning for a serious underlying
condition?
A. Fatigue for 3 weeks following a viral illness
B. Fatigue associated with stress at work
C. Fatigue with unintentional weight loss and night sweats
D. Fatigue with poor sleep quality
Answer: C
Expert Rationale: Fatigue accompanied by constitutional symptoms
(unintentional weight loss, night sweats) is concerning for malignancy, chronic
infection, or systemic inflammatory disease.
13. The NP understands that "anchoring bias" in clinical reasoning refers to:
A. Ordering too many diagnostic tests
B. Relying on the most recent information available
Care
Midterm Examination – Set A (Weeks 1–4)
Chamberlain University | 2026/2027
125 Questions with Expert Rationales
Section 1: Clinical Decision-Making and Diagnostic Reasoning
(Questions 1-20)
1. A 55-year-old male presents with a chief complaint of "fatigue." Which of
the following is the MOST appropriate initial step in the clinical reasoning
process?
A. Order a complete blood count
B. Perform a comprehensive physical examination
C. Obtain a detailed history, including onset, duration, and associated symptoms
D. Prescribe a multivitamin
Answer: C
Expert Rationale: The clinical reasoning process begins with a thorough history.
Fatigue has a broad differential diagnosis; the history guides the differential and
subsequent focused physical exam and testing.
2. The NP is using the differential diagnosis process for a patient with
abdominal pain. Which of the following represents the correct sequence?
A. Hypothesis generation → Data collection → Data interpretation → Problem
identification → Management
B. Data collection → Hypothesis generation → Data interpretation → Problem
identification → Management
C. Data collection → Data interpretation → Hypothesis generation → Problem
identification → Management
,D. Hypothesis generation → Data interpretation → Data collection → Problem
identification → Management
Answer: B
Expert Rationale: The correct sequence is data collection (history, physical) →
hypothesis generation (developing differential diagnoses) → data interpretation
(analyzing findings) → problem identification → management.
3. A 28-year-old female presents with acute-onset severe headache. Which of
the following historical features would be a "red flag" requiring immediate
evaluation?
A. Headache lasting 4 hours with nausea
B. Headache associated with menstruation
C. Sudden-onset "thunderclap" headache
D. Headache with mild photophobia
Answer: C
Expert Rationale: A sudden-onset "thunderclap" headache is a red flag that may
indicate subarachnoid hemorrhage. This requires immediate neuroimaging (non-
contrast CT) and possibly lumbar puncture.
4. Which of the following is an example of a pathognomonic sign in clinical
medicine?
A. Fever in pneumonia
B. Koplik spots in measles
C. Wheezing in asthma
D. Rash in chickenpox
Answer: B
Expert Rationale: Koplik spots (small white spots on the buccal mucosa) are
pathognomonic for measles (rubeola). Pathognomonic signs are uniquely
characteristic of a specific disease.
5. The NP understands that the "pretest probability" of a disease is influenced
by all of the following EXCEPT:
A. Prevalence of the disease in the population
B. Patient's age and gender
C. The cost of diagnostic testing
D. Clinical presentation and risk factors
Answer: C
Expert Rationale: Pretest probability is influenced by disease prevalence, patient
demographics, clinical presentation, and risk factors. Cost of testing does not affect
the probability of disease but may influence whether testing is pursued.
,6. A diagnostic test has a sensitivity of 90% and a specificity of 85%. A negative
result on this test is most useful for:
A. Ruling in the disease
B. Ruling out the disease
C. Confirming the diagnosis
D. Establishing prognosis
Answer: B
Expert Rationale: High sensitivity is useful for ruling out disease (SnNOut: high
Sensitivity, Negative result rules out). A negative result makes the diagnosis unlikely.
7. The NP is considering ordering a D-dimer test for a patient with suspected
deep vein thrombosis. The D-dimer has high sensitivity but low specificity. A
positive D-dimer in a low-risk patient indicates:
A. DVT is confirmed
B. Further testing (ultrasound) is needed
C. No further testing is needed
D. Anticoagulation should be started immediately
Answer: B
Expert Rationale: D-dimer has high sensitivity but low specificity. A positive
result is not diagnostic and requires confirmatory imaging (venous ultrasound) in
patients with suspected DVT.
8. A 45-year-old male presents with chest pain. The NP generates a differential
diagnosis that includes myocardial infarction, GERD, and musculoskeletal pain.
This process is called:
A. Bayesian analysis
B. Hypothesis generation
C. Test interpretation
D. Outcome assessment
Answer: B
Expert Rationale: Hypothesis generation is the process of developing a list of
potential diagnoses based on the initial data (history, physical). This list forms the
differential diagnosis.
9. The NP understands that the "number needed to treat" (NNT) for a
medication is 20. This means:
A. 20 patients need to be treated to prevent one adverse outcome
B. The medication costs $20 per dose
C. 20% of patients will experience an adverse effect
D. The medication is 20% effective
, Answer: A
Expert Rationale: NNT is the number of patients who need to be treated to
prevent one additional adverse outcome. A lower NNT indicates a more effective
treatment.
10. A 62-year-old male presents with a 3-month history of unintentional weight
loss and night sweats. These symptoms are classified as:
A. Local symptoms
B. Constitutional symptoms
C. Psychosomatic symptoms
D. Acute symptoms
Answer: B
Expert Rationale: Constitutional symptoms are systemic symptoms that affect
the entire body, including unintentional weight loss, fever, night sweats, and fatigue.
11. The NP is evaluating a patient with a chief complaint of "dizziness." The
patient describes a sensation of spinning. This is correctly termed:
A. Lightheadedness
B. Vertigo
C. Disequilibrium
D. Presyncope
Answer: B
Expert Rationale: Vertigo is the false sensation of movement, typically spinning
or rotational. It is important to distinguish vertigo from lightheadedness,
disequilibrium, and presyncope.
12. A 35-year-old female presents with fatigue. Which of the following
historical elements would be MOST concerning for a serious underlying
condition?
A. Fatigue for 3 weeks following a viral illness
B. Fatigue associated with stress at work
C. Fatigue with unintentional weight loss and night sweats
D. Fatigue with poor sleep quality
Answer: C
Expert Rationale: Fatigue accompanied by constitutional symptoms
(unintentional weight loss, night sweats) is concerning for malignancy, chronic
infection, or systemic inflammatory disease.
13. The NP understands that "anchoring bias" in clinical reasoning refers to:
A. Ordering too many diagnostic tests
B. Relying on the most recent information available
