,NSG 550 Diagnostic Reasoning Final Exam
Wilkes University Study Guide Clinical
1. A nurse practitioner enters a patient's room and within seconds determines that the patient
appears acutely ill and requires immediate intervention. This rapid assessment best exemplifies
which type of clinical reasoning process according to the dual-process model?
A. Type 2 analytical reasoning involving systematic data collection
B. Type 1 intuitive reasoning that is rapid and pattern-based
C. Bayesian reasoning that incorporates pre-test probability
D. Hypothetico-deductive reasoning with sequential hypothesis testing
Correct Answer: B. Type 1 intuitive reasoning that is rapid and pattern-based
Rationale: Type 1 (intuitive) reasoning is rapid, subconscious, and pattern-based; recognizing
"sick vs. not sick" within seconds of entering a patient's room is a hallmark of intuitive
processing. Options A, C, and D involve deliberate, analytical (Type 2) reasoning.
2. A 45-year-old patient presents with epigastric pain, and the nurse practitioner generates a
differential diagnosis that includes GERD, peptic ulcer disease, biliary colic, and cardiac
ischemia. This list of potential diagnoses is best described as which of the following?
A. Working diagnosis based on the most likely condition
B. Anatomical differential organized by organ system
C. Exhaustive differential including all reasonable possibilities
D. Pathophysiologic cascade of disease progression
,Correct Answer: C. Exhaustive differential including all reasonable possibilities
Rationale: An exhaustive differential includes all reasonable possibilities before narrowing to the
most likely diagnosis; the working diagnosis is the most likely after reasoning, and an anatomical
differential organizes by organ system.
3. The sensitivity of a diagnostic test refers to its ability to accomplish which of the following
clinical objectives?
A. Correctly identify those without the disease (true negative rate)
B. Correctly identify those with the disease (true positive rate)
C. Produce the same result on repeated testing (reliability)
D. Predict the probability of disease after a positive result
Correct Answer: B. Correctly identify those with the disease (true positive rate)
Rationale: Sensitivity = True Positives / (True Positives + False Negatives); high sensitivity rules
out disease when negative (SnNout). Specificity (option A) is the true negative rate and rules in
disease when positive (SpPin).
4. A test with 95% specificity is used in a low-prevalence population. A positive result most likely
indicates:
, A. High positive predictive value
B. Low positive predictive value
C. High negative predictive value
D. The test is invalid
Correct Answer: B. Low positive predictive value
Rationale: PPV is directly influenced by disease prevalence. In a low-prevalence population,
even a highly specific test will have a low PPV because most positive results will be false
positives. This is a critical concept in Bayesian reasoning and screening test interpretation.
5. Which of the following is TRUE regarding the positive predictive value (PPV) of a diagnostic
test?
A. PPV is independent of disease prevalence
B. PPV increases as disease prevalence increases
C. PPV is the same as sensitivity
D. PPV is the probability that a person with disease tests positive
Correct Answer: B. PPV increases as disease prevalence increases
Rationale: PPV is the probability that a person with a positive test actually has the disease. It is
directly influenced by disease prevalence: as prevalence increases, PPV increases. Sensitivity is
the probability that a person with disease tests positive.
Wilkes University Study Guide Clinical
1. A nurse practitioner enters a patient's room and within seconds determines that the patient
appears acutely ill and requires immediate intervention. This rapid assessment best exemplifies
which type of clinical reasoning process according to the dual-process model?
A. Type 2 analytical reasoning involving systematic data collection
B. Type 1 intuitive reasoning that is rapid and pattern-based
C. Bayesian reasoning that incorporates pre-test probability
D. Hypothetico-deductive reasoning with sequential hypothesis testing
Correct Answer: B. Type 1 intuitive reasoning that is rapid and pattern-based
Rationale: Type 1 (intuitive) reasoning is rapid, subconscious, and pattern-based; recognizing
"sick vs. not sick" within seconds of entering a patient's room is a hallmark of intuitive
processing. Options A, C, and D involve deliberate, analytical (Type 2) reasoning.
2. A 45-year-old patient presents with epigastric pain, and the nurse practitioner generates a
differential diagnosis that includes GERD, peptic ulcer disease, biliary colic, and cardiac
ischemia. This list of potential diagnoses is best described as which of the following?
A. Working diagnosis based on the most likely condition
B. Anatomical differential organized by organ system
C. Exhaustive differential including all reasonable possibilities
D. Pathophysiologic cascade of disease progression
,Correct Answer: C. Exhaustive differential including all reasonable possibilities
Rationale: An exhaustive differential includes all reasonable possibilities before narrowing to the
most likely diagnosis; the working diagnosis is the most likely after reasoning, and an anatomical
differential organizes by organ system.
3. The sensitivity of a diagnostic test refers to its ability to accomplish which of the following
clinical objectives?
A. Correctly identify those without the disease (true negative rate)
B. Correctly identify those with the disease (true positive rate)
C. Produce the same result on repeated testing (reliability)
D. Predict the probability of disease after a positive result
Correct Answer: B. Correctly identify those with the disease (true positive rate)
Rationale: Sensitivity = True Positives / (True Positives + False Negatives); high sensitivity rules
out disease when negative (SnNout). Specificity (option A) is the true negative rate and rules in
disease when positive (SpPin).
4. A test with 95% specificity is used in a low-prevalence population. A positive result most likely
indicates:
, A. High positive predictive value
B. Low positive predictive value
C. High negative predictive value
D. The test is invalid
Correct Answer: B. Low positive predictive value
Rationale: PPV is directly influenced by disease prevalence. In a low-prevalence population,
even a highly specific test will have a low PPV because most positive results will be false
positives. This is a critical concept in Bayesian reasoning and screening test interpretation.
5. Which of the following is TRUE regarding the positive predictive value (PPV) of a diagnostic
test?
A. PPV is independent of disease prevalence
B. PPV increases as disease prevalence increases
C. PPV is the same as sensitivity
D. PPV is the probability that a person with disease tests positive
Correct Answer: B. PPV increases as disease prevalence increases
Rationale: PPV is the probability that a person with a positive test actually has the disease. It is
directly influenced by disease prevalence: as prevalence increases, PPV increases. Sensitivity is
the probability that a person with disease tests positive.
