Davidson’s Mock Exam Answers

A clinician is evaluating a 30-year-old male with recurrent headaches and orders an MRI, which shows incidental white matter hyperintensities. In interpreting these findings, what is an essential consideration?

A patient with a history of hypertension undergoes an electrocardiogram (ECG) with mild ST depression of 0.5 mm. Considering that a 0.5 mm cut-off point provides high sensitivity but low specificity for coronary artery disease (CAD), how should this result be interpreted?

A 50-year-old woman with chronic fatigue has a TSH level at the upper limit of the reference range. Her physician suspects hypothyroidism due to her symptoms, but the reference range encompasses 95% of the population, meaning some normal patients may have TSH levels outside this range. Which of the following statements best explains the concept of “reference range”?

A 60-year-old man presents with severe left hip pain after a fall. Hip X-rays show no signs of fracture. Considering that X-ray sensitivity for hip fractures is around 90% in high-risk patients, what should be the next best step in his management?

A 45-year-old woman with a family history of breast cancer undergoes a mammogram screening, which yields a positive result. The test sensitivity is 90%, and the specificity is 95%. However, in her age group, the prevalence of breast cancer is only 1%. What is the best estimate of her probability of having breast cancer after a positive test result?

A 30-year-old man presents with recurrent fever, weight loss, and a history of recent travel to a malaria-endemic area. Despite a negative initial malaria smear, the physician strongly suspects malaria and orders multiple repeat tests, even as other possible causes are overlooked. What clinical error is most represented in this case?

A junior doctor reviews a 58-year-old patient with abdominal pain and jaundice. The patient’s chart indicates a recent gallstone removal, so the junior doctor immediately concludes that the symptoms are due to post-cholecystectomy syndrome and requests symptomatic treatment only. Which type of cognitive bias is most likely affecting this junior doctor’s decision-making?

A 42-year-old woman presents with a sudden onset of severe headache, fever, and neck stiffness. The doctor considers the classic signs of meningitis but notes that the patient does not have photophobia or a positive Brudzinski’s sign. She decides against a lumbar puncture, reasoning that the patient does not exhibit the full set of symptoms for meningitis. Which clinical reasoning concept is most relevant to this situation?

A 68-year-old man with a history of chronic obstructive pulmonary disease (COPD) and congestive heart failure presents to the emergency department with shortness of breath. He has hypoxia and his chest X-ray reveals bilateral pulmonary infiltrates. The physician, focused on his known cardiac and respiratory conditions, suspects an exacerbation of COPD or heart failure and initiates treatment accordingly. Which cognitive bias could lead to a missed diagnosis in this case?

A 55-year-old woman with poorly controlled type 2 diabetes presents with fever, right upper quadrant pain, and jaundice. Her blood tests reveal elevated white cell count and liver enzymes. Ultrasound shows gallbladder wall thickening and pericholecystic fluid, suggesting acute cholecystitis. The physician interprets this as the definitive diagnosis. Which of the following best describes a cognitive error that may occur in this scenario?

A physician reviewing a 45-year-old male patient’s suspected DVT applies the Wells score and advises imaging based on the score. This action exemplifies which aspect of clinical reasoning?

A 30-year-old woman presents with recurrent episodes of fainting. Her physician, after an initial exam, orders extensive tests despite there being no findings suggestive of a serious cause. The physician is applying a strategy to avoid missing a serious diagnosis.
Which strategy is most likely in use here?

A 60-year-old man is in the intensive care unit following surgery. The nurse uses the SBAR (Situation, Background, Assessment, Recommendation) format to communicate a significant drop in the patient’s blood pressure to the on-call doctor.
What is the primary benefit of using the SBAR method?

A 55-year-old woman with a history of breast cancer is hospitalized with pneumonia. A junior doctor considers initiating aggressive antibiotic therapy but is unsure. The supervising physician recommends applying the CURB-65 score for pneumonia severity to guide the treatment.
Which of the following best describes the tool used in this scenario?

A 65-year-old woman with well-controlled hypertension and type 2 diabetes is recommended for surgery. The clinician uses visual aids to explain the potential benefits and risks of the operation, stating that “90 out of 100 patients improve, 5 experience minor complications, and 2 suffer serious complications.” The patient feels well-informed after the discussion.
Which of the following aspects of communication does this represent?

A 72-year-old man with chronic obstructive pulmonary disease (COPD) and newly diagnosed prostate cancer discusses treatment options with his oncologist. He is informed of the potential benefits and side effects of different treatments, including chemotherapy and palliative care. He expresses concerns about his quality of life over aggressive treatment.
Which of the following best describes the approach the physician should take in this case?

A medical student sees a patient with symptoms suggestive of meningitis and is asked to assess the case. The student recalls recent cases of viral meningitis from a lecture and initially considers this over bacterial causes, even though bacterial meningitis is more life-threatening.
Which cognitive bias is affecting the student’s judgment?

A 40-year-old woman with abdominal pain and fever is labeled as having a “simple case of gastroenteritis” by the initial team in the Emergency Department. Despite further symptoms developing, subsequent teams continue with the initial diagnosis and do not explore alternative causes.
Which bias is most likely influencing the subsequent teams’ clinical decision-making?

A junior doctor evaluates a 70-year-old man with confusion, fever, and productive cough, considering pneumonia as the primary diagnosis. However, they do not ask about the patient’s recent travel history, which would reveal potential exposure to tuberculosis (TB) in an endemic region.
Which bias might explain the doctor’s omission in this case?

A 65-year-old man with a known history of atrial fibrillation and hypertension presents with sudden, severe headache, left-sided weakness, and slurred speech. The emergency team immediately begins treatment for ischemic stroke based on initial symptoms.
What cognitive process should the team utilize to minimize diagnostic error in this high-stakes situation?

A 27-year-old woman presents to the Emergency Department with sudden onset left-sided pleuritic chest pain and breathlessness. She has a history of anxiety and is known to present with panic attacks. The attending physician interprets her symptoms as another panic episode and plans for discharge with anxiolytics.
Which cognitive error is most likely affecting the physician’s judgment?

A patient presents with suspected meningitis. The physician notes neck stiffness but decides against lumbar puncture due to absence of fever and headache. The patient later deteriorates and is confirmed to have bacterial meningitis.

A 34-year-old man with no significant past medical history presents with sudden chest pain and syncope while exercising. The ED team initially suspects a cardiac cause but reverts to diagnosing a panic attack after normal initial workup.

A 72-year-old woman with a history of osteoporosis presents after a fall, complaining of hip pain. X-rays are inconclusive, but the physician discharges her. The next day, she returns with worsening pain and is found to have an occult hip fracture.

A 28-year-old man with anxiety is brought to the ED with chest pain and palpitations. Despite the patient describing atypical chest pain, the physician attributes it solely to anxiety due to his known psychiatric history.

A 50-year-old woman with a history of atrial fibrillation on warfarin presents with sudden onset of severe back pain. A physician considers a musculoskeletal etiology due to her recent fall and prescribes analgesics. Later, she is diagnosed with a retroperitoneal hemorrhage.

A 45-year-old man with chronic headaches is given a diagnosis of tension-type headaches by his family physician. He presents to the Emergency Department with worsening headaches and visual disturbances. The physician accepts the previous diagnosis of tension headaches without reassessing the case fully.

A 58-year-old woman with a history of type 2 diabetes presents with vomiting and abdominal pain. The junior doctor attributes her symptoms to diabetic gastroparesis. No additional tests are ordered, and she is discharged with symptomatic treatment. She is later found to have a bowel obstruction.

A 29-year-old woman presents to the Emergency Department with pleuritic chest pain and shortness of breath. She mentions recent travel and her use of oral contraceptives. The physician, who recently managed a series of similar cases, quickly diagnoses pulmonary embolism and orders anticoagulation before obtaining further tests.

A 35-year-old man presents with sudden, severe abdominal pain and hypotension. His medical history includes a recent diagnosis of diverticulitis. The on-call doctor attributes his symptoms to diverticulitis flare-up and discharges him with analgesics. Hours later, he is readmitted with a ruptured abdominal aortic aneurysm.

A 62-year-old woman presents with a two-week history of fatigue, dyspnea, and pedal edema. She is known to have heart failure, and on examination, she appears pale with an elevated jugular venous pressure. The initial working diagnosis is a heart failure exacerbation, and the physician orders diuretics.

A 52-year-old man with a mild ankle sprain is concerned about the risks of treatment after being informed of the common side effects of NSAIDs. His physician uses consistent numerical data to explain the likelihood of side effects.

A 68-year-old patient with suspected pulmonary embolism is evaluated with a modified Wells score and has a low pre-test probability. However, a D-dimer test is ordered, returning positive. The physician interprets this cautiously, avoiding over-reliance on the D-dimer.

A junior doctor, unsure of the diagnosis of an elderly patient with abdominal pain and weight loss, requests input from a senior colleague. This step is an example of:

A 75-year-old man with advanced dementia and a recent myocardial infarction is being considered for anticoagulation therapy. The patient’s family is involved in the decision-making process, considering both medical recommendations and quality-of-life concerns. Which of the following best describes this approach?

A 27-year-old man with asthma presents with worsening dyspnea. His blood gas shows normal PaCO₂, leading the physician to consider it as reassuring. He is later admitted with severe asthma exacerbation.

What best explains the missed clinical cue in this case?

A physician suspects a deep vein thrombosis (DVT) in a 65-year-old patient based on her symptoms. The pre-test probability is low, and a D-dimer test is ordered, which returns negative.

What concept supports using the test in this setting?

A 42-year-old woman with a history of frequent sinus infections presents with fever, malaise, and unilateral facial swelling. The physician considers orbital cellulitis as a possibility but decides on a watch-and-wait approach due to low suspicion.

What concept does this illustrate regarding decision thresholds?

A 59-year-old man with worsening breathlessness is evaluated. His test results reveal a restrictive pattern on pulmonary function tests and elevated serum calcium. The physician suspects sarcoidosis and orders a biopsy.

What type of clinical decision-making is being applied here?

A 66-year-old man with a history of prostate cancer presents with back pain and new-onset urinary retention. The ED team considers metastatic spinal cord compression but attributes the symptoms to lumbar spondylosis based on X-ray findings.

Which reasoning error could delay the diagnosis?

A 47-year-old man is diagnosed with likely acute cholecystitis based on clinical presentation and ultrasound. The physician explains that additional imaging may not be needed if his symptoms improve with antibiotics.

What reasoning concept is the physician applying?

A 70-year-old woman is prescribed bisphosphonates for osteoporosis but has severe dyspepsia and refuses the medication. Her physician considers alternative treatments and schedules a shared decision-making session to discuss risks and benefits of other therapies.

What does this approach best exemplify?

A physician orders a highly sensitive blood test for a rare disease in a patient with minimal symptoms. The test returns a positive result, but the patient is later found not to have the disease.

What concept is relevant in interpreting the test results?

A 30-year-old woman with a history of chronic fatigue syndrome presents with chest pain, palpitations, and syncope. Her doctor attributes her symptoms to her underlying condition. However, an ECG shows a prolonged QT interval, leading to a diagnosis of long QT syndrome.

What cognitive bias could have delayed her diagnosis?

A 55-year-old man with sudden vision loss in his left eye undergoes fundoscopy, which reveals retinal pallor consistent with central retinal artery occlusion (CRAO). The physician explains that further intervention may not improve his vision but emphasizes the need for stroke prevention.

Which reasoning concept is relevant here regarding treatment options?

A 38-year-old woman with newly diagnosed hypertension is told by her physician that she must monitor her blood pressure at home to establish a baseline. She asks about the implications of fluctuating values on her health.

Which of the following best explains how normal variability might impact her results?

A 25-year-old man presents with a two-day history of fever, cough, and pleuritic chest pain. His physician suspects bacterial pneumonia and orders a chest X-ray, which is unremarkable. The physician decides against further tests due to the low clinical suspicion of other diagnoses.

What key clinical principle is applied here?

A 60-year-old woman presents with weight loss, fatigue, and a change in bowel habits. Despite the vague symptoms, the physician suspects colorectal cancer and arranges a colonoscopy. The patient undergoes the procedure, which confirms the diagnosis.

What type of clinical decision-making strategy is illustrated in this case?

A 50-year-old man with a history of hypertension and chronic kidney disease is admitted with elevated blood pressure and dyspnea. The initial working diagnosis is acute heart failure, but on further evaluation, the patient is found to have severe anemia. The team revises the diagnosis to anemia-induced high-output heart failure and adjusts management accordingly.

Which clinical reasoning concept does this example best illustrate?

A 40-year-old woman with a history of rheumatoid arthritis presents with fatigue, joint pain, and breathlessness. Her physician suspects interstitial lung disease based on her symptoms and history of methotrexate use. Chest X-ray and pulmonary function tests are normal, so the physician reassures her and discharges her.

What clinical reasoning principle is not fully applied in this scenario?