Differential Diagnosis & Primary Care Practicum | Latest
Update 2026/2027 | 200 Practice Questions & Detailed
Answers | Examplify Proctored | A+ Graded
1. Define diagnostic reasoning.
A) The ability to memorize disease presentations
B) A systematic way of thinking that evaluates each new piece of data as it either supports a diagnostic
hypothesis or reduces the likelihood of others
C) The process of ordering laboratory tests
D) The act of performing a physical examination
Answer: B) A systematic way of thinking that evaluates each new piece of data as it either supports a
diagnostic hypothesis or reduces the likelihood of others
Explanation: Diagnostic reasoning is a systematic, reflective thinking process that evaluates clinical data
to support or refute diagnostic hypotheses. It is the cognitive foundation of clinical judgment and
involves critical thinking, not memorization or test ordering.
2. What is the first step in the diagnostic reasoning process?
A) Physical examination
B) History of present illness (HPI)
C) Ordering diagnostic tests
D) Formulating a differential diagnosis
Answer: B) History of present illness (HPI)
Explanation: The HPI is the first step in diagnostic reasoning. It uses the OLDCARTS mnemonic to gather
detailed information about the chief complaint.
,3. A diagnostic test has very few false negatives. How is this test best described?
A) High specificity
B) Low specificity
C) High sensitivity
D) Low sensitivity
Answer: C) High sensitivity
Explanation: A highly sensitive test correctly identifies most people who have the condition, resulting in
very few false negatives. This makes it a good test to help rule out a disease when negative.
4. What is the likelihood ratio in clinical decisionmaking?
A) The probability of disease before testing
B) How likely it is that a patient has the disease; when the ratio is higher, it is more likely they have the
disease
C) The false positive rate
D) The false negative rate
Answer: B) How likely it is that a patient has the disease; when the ratio is higher, it is more likely they
have the disease
Explanation: The likelihood ratio indicates how much a test result changes the probability of disease. A
higher likelihood ratio (LR+) means a positive test is more likely in a patient with the disease.
5. Which of the following is a crucial element of developing a clinical guideline?
,A) Basing recommendations on expert opinion only
B) Using a systematic review of current evidence
C) Including only randomized controlled trials
D) Relying on a single case study
Answer: B) Using a systematic review of current evidence
Explanation: Clinical guidelines must be based on a systematic review of current evidence, not expert
opinion alone. This ensures recommendations are evidencebased and clinically valid.
6. Which is the most important question to ask in evidencebased practice?
A) What findings are most relevant to the patient's problem?
B) What is the most costeffective treatment?
C) What does the pharmaceutical representative recommend?
D) What is the quickest diagnostic test available?
Answer: A) What findings are most relevant to the patient's problem?
Explanation: Evidencebased practice begins with formulating a focused clinical question based on the
patient's problem, then searching for the best available evidence to answer that question.
7. A 24yearold female presents with a 3day history of sore throat, 101.2°F fever, and "white patches" on
tonsils. She has no cough, no rhinorrhea, and tender anterior cervical nodes. Which single HPI question
best refines your differential before exam?
A) "Do you have night sweats?"
B) "Have you had similar symptoms before?"
C) "Do you have any joint pain or rash?"
D) "Have you been exposed to anyone with strep throat?"
, Answer: D) "Have you been exposed to anyone with strep throat?"
Explanation: Exposure history immediately raises pretest probability for group A strep (GAS) and guides
rapid testing. Always ask about strep exposure; it's one of the five Centor criteria.
8. A 38yearold man describes a 2week "pressure" headache, worse in morning, no nausea, no visual
changes. He takes OTC ibuprofen 600 mg BID with partial relief. PMH: obesity, HTN. Which redflag
symptom requires immediate action?
A) Morning predominance
B) Partial relief with NSAID
C) Absence of nausea
D) 2week duration
Answer: A) Morning predominance
Explanation: Morning headache with obesity and HTN suggests raised intracranial pressure until proven
otherwise. Morning headaches are a classic sign of elevated ICP—image early.
9. A 31yearold woman, 8 weeks postpartum, complains of 4day "racing heart" and feeling "shaky." She
is breastfeeding and sleeping 3–4 h/night. No chest pain. Which HPI element best clarifies etiology?
A) Family history of thyroid disease
B) Timing of symptoms relative to sleep
C) Caffeine intake (mg/day)
D) Obstetric bloodloss amount
Answer: B) Timing of symptoms relative to sleep
Explanation: Shaky and racing after only 3 h sleep strongly suggests sleep deprivation; clarifies benign vs.
pathologic. Always correlate palpitations with sleep quantity in new moms.