Clinical decision rules — MCQs

A 67-year-old woman presents with right leg pain and swelling of 5 days’ duration. She has a history of hypertension for 15 years and had a recent hospitalization for pneumonia. She had been recuperating at home but on beginning to mobilize and walk, the right leg became painful and swollen. Her temperature is 37.1°C (98.7°F), the blood pressure is 130/80 mm Hg, and the pulse is 75/min. On physical examination, the right calf is 4 cm greater in circumference than the left when measured 10 cm below the tibial tuberosity. Dilated superficial veins are present on the right foot and the right leg is slightly redder than the left. There is some tenderness on palpation in the popliteal fossa behind the knee. Which of the following is the best initial step in the management of this patient’s condition?

You are reading through a recent article that reports significant decreases in all-cause mortality for patients with malignant melanoma following treatment with a novel biological infusion. Which of the following choices refers to the probability that a study will find a statistically significant difference when one truly does exist?

A 25-year-old man comes to the physician for severe back pain. He describes the pain as shooting and stabbing. On a 10-point scale, he rates the pain as a 9 to 10. The pain started after he lifted a heavy box at work; he works at a supermarket and recently switched from being a cashier to a storekeeper. The patient appears to be in severe distress. Vital signs are within normal limits. On physical examination, the spine is nontender without paravertebral muscle spasms. Range of motion is normal. A straight-leg raise test is negative. After the physical examination has been completed, the patient asks for a letter to his employer attesting to his inability to work as a storekeeper. Which of the following is the most appropriate response?

A medical research study is beginning to evaluate the positive predictive value of a novel blood test for non-Hodgkin’s lymphoma. The diagnostic arm contains 700 patients with NHL, of which 400 tested positive for the novel blood test. In the control arm, 700 age-matched control patients are enrolled and 0 are found positive for the novel test. What is the PPV of this test?

A student health coordinator plans on leading a campus-wide HIV screening program that will be free for the entire undergraduate student body. The goal is to capture as many correct HIV diagnoses as possible with the fewest false positives. The coordinator consults with the hospital to see which tests are available to use for this program. Test A has a sensitivity of 0.92 and a specificity of 0.99. Test B has a sensitivity of 0.95 and a specificity of 0.96. Test C has a sensitivity of 0.98 and a specificity of 0.93. Which of the following testing schemes should the coordinator pursue?

An orthopaedic surgeon at a local community hospital has noticed that turnover times in the operating room have been unnecessarily long. She believes that the long wait times may be due to inefficient communication between the surgical nursing staff, the staff in the pre-operative area, and the staff in the post-operative receiving area. She believes a secure communication mobile phone app would help to streamline communication between providers and improve efficiency in turnover times. Which of the following methods is most appropriate to evaluate the impact of this intervention in the clinical setting?

A 78-year-old woman is brought to the emergency ward by her son for lethargy and generalized weakness. The patient speaks in short utterances and does not make eye contact with the provider or her son throughout the interview and examination. You elicit that the patient lives with her son and daughter-in-law, and she reports vague weakness for the last couple days. The emergency room provider notices 3-4 healing bruises on the patient's upper extremities; otherwise, examination is not revealing. Routine chemistries and blood counts are unremarkable; non-contrast head CT demonstrates normal age-related changes. Which of the following is the most appropriate next step in management?

A 65-year-old man is admitted to the hospital because of a 1-month history of fatigue, intermittent fever, and weakness. Results from a peripheral blood smear taken during his evaluation are indicative of possible acute myeloid leukemia. Bone marrow aspiration and subsequent cytogenetic studies confirm the diagnosis. The physician sets aside an appointed time-slot and arranges a meeting in a quiet office to inform him about the diagnosis and discuss his options. He has been encouraged to bring someone along to the appointment if he wanted. He comes to your office at the appointed time with his daughter. He appears relaxed, with a full range of affect. Which of the following is the most appropriate opening statement in this situation?

A 27-year-old woman presents to her primary care physician for minor aches and pains in her bones and muscles. She states that these symptoms have persisted throughout her entire life but have worsened recently when she moved to attend college. The patient is physically active, and states that she eats a balanced diet. She is currently a full-time student and is sexually active with 1 partner. She states that she has been particularly stressed lately studying for final exams and occasionally experiences diarrhea. She has been taking acyclovir for a dermatologic herpes simplex virus infection with minimal improvement. On physical exam, the patient exhibits 4/5 strength in her upper and lower extremities, and diffuse tenderness over her limbs that is non-specific. Laboratory values are ordered as seen below: Serum: Na+: 144 mEq/L Cl-: 102 mEq/L K+: 4.7 mEq/L HCO3-: 24 mEq/L Ca2+: 5.0 Urea nitrogen: 15 mg/dL Glucose: 81 mg/dL Creatinine: 1.0 mg/dL Alkaline phosphatase: 225 U/L Aspartate aminotransferase (AST, GOT): 11 U/L Alanine aminotransferase (ALT, GPT): 15 U/L Which of the following is most likely associated with this patient’s presentation?

A 64-year-old female presents to her primary care physician for an annual checkup. She states that her health is adequate, but she has not been doing well since her husband died last year. She is able to get by but admits to having trouble caring for herself, cooking, cleaning, and paying her bills. The patient complains of diffuse muscle aches and pains. She has a past medical history of anxiety and seasonal affective disorder. She is not currently taking any medications. On physical exam, you note a gaunt woman with a depressed affect. You note that her body mass index (BMI) and height have both decreased since her last annual visit. On physical exam, her cardiac, pulmonary, and abdominal exams are within normal limits. Lab work is drawn and is as follows: Serum: Na+: 135 mEq/L K+: 3.7 mEq/L Cl-: 100 mEq/L HCO3-: 23 mEq/L Urea nitrogen: 7 mg/dL Glucose: 70 mg/dL Creatinine: 0.8 mg/dL Ca2+: 8.0 mg/dL Mg2+: 1.5 mEq/L Parathyroid hormone: 855 pg/mL Alkaline phosphatase: 135 U/L Phosphorus: 2.6 mg/dL Hemoglobin: 14 g/dL Hematocrit: 36% Platelet count: 187,000/mm^3 Leukocyte count: 4,700/mm^3 What is the most likely diagnosis?