All practice questions

A clinical laboratory is validating a new quantitative blood assay for a tumor marker used to screen for a specific cancer. Initially, the test yields a high number of false-positive results, leading to patient anxiety and unnecessary invasive biopsies. To address this, the laboratory advisory committee decides to adjust the test's diagnostic threshold (cut-off value) so that a result is only considered 'positive' at a much higher serum concentration.

Assuming the underlying prevalence of the cancer in the screened population remains unchanged, which of the following statistical consequences is most likely to result directly from this threshold adjustment?

A 68-year-old man undergoes a screening colonoscopy. A 15-mm sessile polyp is identified in the sigmoid colon and removed via snare polypectomy. Four hours after discharge, the patient presents to the emergency department with severe, diffuse abdominal pain, tachycardia, and rigidity. An upright chest radiograph shows free air under the diaphragm. The patient is taken for an emergent exploratory laparotomy, which reveals a 1-cm perforation at the polypectomy site. The surgical team notes that the bowel wall in that segment was severely thinned due to extensive underlying diverticular disease. The patient undergoes a partial colectomy with a temporary colostomy. He requires a 14-day hospital stay and misses two months of work.

The patient subsequently files a medical malpractice lawsuit against the gastroenterologist. During discovery, independent expert witnesses for both the plaintiff and the defense review the case. They unanimously agree that the gastroenterologist utilized the correct technique, applied appropriate electrocautery settings, and acted in complete accordance with accepted medical standards for polyp removal. The risk of perforation was explicitly discussed with the patient and documented in the signed informed consent form.

Based on these facts, which of the following best describes the most likely outcome of the malpractice claim and its primary legal rationale?

A public health physician is reviewing annual surveillance statistics for a municipality with a total population of $250,000$ individuals. Over the course of the previous year, there were $2,000$ recorded deaths from all causes. The health department's registry indicates that $5,000$ residents were living with chronic liver disease during this same period. Death certificate analysis reveals that $400$ of the total deaths were directly attributed to complications of chronic liver disease. The physician is tasked with preparing a brief regarding the relative burden of different causes of death. Based on this data, what is the proportionate mortality for chronic liver disease in this municipality?

An elderly male resident of an assisted living facility arrives at the emergency department with severe generalized abdominal pain, fever, and rigidity. A CT scan confirms free air in the abdomen, necessitating an immediate exploratory laparotomy. Upon discussing the surgical risks and benefits, the patient shakes his head and says, "My television told me that scalpels are poisonous today." He has a known history of severe Alzheimer disease. The surgical team recognizes the need to properly navigate the legal and ethical framework to obtain authorization for the operation.

Arrange the following actions in the legally and ethically appropriate chronological sequence to obtain consent for this patient, from first to last.

A 52-year-old woman with a 25-year history of treatment-resistant schizophrenia is evaluated in the clinic following a recent colonoscopy that revealed a large, obstructing adenocarcinoma of the ascending colon. The surgical oncology team recommends an urgent bowel resection. During the discussion, the patient appears disheveled and occasionally mumbles to herself. She correctly identifies her diagnosis, stating, "I have a tumor that will block my intestines and cause me to die." However, she declines the surgery. When asked for her reasoning, she says, "My father had the same surgery, and he spent his last six months in the ICU with tubes everywhere. I want to die peacefully at home, even if it happens sooner." She acknowledges that the voices she hears are currently telling her that the hospital food is poisoned, but she explicitly states, "I'm not refusing because of the voices; I just don't want the surgery." Which of the following is the most appropriate next step in management?

As the evening shift approaches, an attending physician on the hospitalist service is overseeing the transition of care for a 64-year-old man admitted for urosepsis. The patient is currently hemodynamically stable on intravenous antibiotics but is deemed at high risk for clinical deterioration. The institution strictly mandates the use of the I-PASS handoff protocol to standardize communication between shifts. Arrange the following communicative actions in the correct chronological sequence as they should be performed according to this framework.

A physician at a community clinic is interested in the long-term health outcomes of a popular high-protein diet. She identifies 500 healthy adult patients in her practice who report strictly following this diet and 500 healthy adults of similar ages who consume a standard diet. At the time of enrollment, none of the 1,000 patients have a history of cardiovascular disease. The physician plans to review their medical records annually for the next 10 years to determine the incidence of new-onset hypertension and myocardial infarction in both groups. Which of the following best describes this study design?

A public health research team is evaluating the longitudinal risk of end-stage renal disease (ESRD) in a community population. They assemble a dynamic cohort of $1,500$ adult patients who have recently been diagnosed with severe hypertension but have normal renal function at baseline. The cohort is actively monitored for exactly $10$ years. During this period, the researchers observe the following events and attrition:

- $600$ subjects complete the entire $10$-year study without showing any clinical signs of ESRD.
- $400$ subjects move out of the study region and are lost to follow-up precisely at the end of year $5$; all of these individuals were free of ESRD at the time of their departure.
- $300$ subjects are diagnosed with incident ESRD precisely at the end of year $4$.
- $200$ subjects die from acute cardiovascular events precisely at the end of year $4$, without having developed ESRD prior to death.

Assuming no other losses or events occurred, which of the following is the incidence rate of ESRD in this cohort?

A 68-year-old man is evaluated in the medical intensive care unit. He has been mechanically ventilated for the past 8 days for acute respiratory distress syndrome secondary to severe acute pancreatitis. Over the last 24 hours, the respiratory therapist reports a significant increase in the volume of thick, purulent endotracheal secretions. The patient appears comfortable on the ventilator. Temperature is 37.4°C (99.3°F), blood pressure is 132/78 mm Hg, pulse is 86/min, and respirations are 16/min (matching the ventilator set rate). Current ventilator settings include a fraction of inspired oxygen (FiO2) of 0.35 and positive end-expiratory pressure (PEEP) of 5 cm $H_2O$, which have been stable for the past 3 days. Physical examination reveals coarse upper airway rhonchi that clear completely with in-line suctioning. Leukocyte count is 8,200/$mm^3$. A chest radiograph demonstrates stable, resolving bilateral ground-glass opacities with no new focal consolidations. A routine endotracheal aspirate culture sent earlier today returns heavy growth of Pseudomonas aeruginosa. Which of the following is the most appropriate next step in management?

Match each clinical-legal scenario to the specific medicolegal doctrine it best illustrates.

A hospital's diagnostic stewardship committee is analyzing how different clinical adjustments and epidemiological shifts will impact the statistical performance metrics of their diagnostic assays. Match each proposed change in testing strategy with its direct mathematical consequence on the test's performance parameters.

An emergency department physician evaluates a 35-year-old woman who sustained a 4-cm laceration on her left outer thigh. The patient states she tripped and fell onto a piece of broken glass while cleaning her garage. On physical examination, the laceration is deep with sharp, linear margins, and there are multiple fading contusions on her upper arms and neck. The physician asks the patient's partner to step out of the room. When interviewed alone, the patient tearfully discloses that her boyfriend stabbed her with a pocketknife during a heated argument. She begs the physician, "Please do not tell the police. He will kill me if he gets arrested, and I have nowhere else to go." The patient is alert, oriented, and demonstrates a clear understanding of her situation and the risks involved. Which of the following is the most appropriate next step in management?

Match each epidemiological study scenario or clinical investigation (left) with the most appropriate measure of disease frequency used to describe the findings (right).

A 68-year-old man with a history of hypertension, hyperlipidemia, and a previous transient ischemic attack is admitted to the hospital for an elective right total knee arthroplasty. His preoperative workup is unremarkable. The surgery proceeds smoothly, and he is transferred to the orthopedic ward. In accordance with the hospital's evidence-based venous thromboembolism prophylaxis protocol, he is prescribed subcutaneous enoxaparin and sequential compression devices. The electronic health record confirms that all doses of enoxaparin are administered on schedule and the compression devices are actively functioning. On postoperative day 4, the patient experiences sudden-onset dyspnea, tachycardia, and right-sided pleuritic chest pain. A CT pulmonary angiogram confirms a segmental pulmonary embolism. The patient is immediately started on a therapeutic dose of intravenous unfractionated heparin, and his symptoms gradually improve. An internal quality review of the case concludes that all prophylactic measures and clinical guidelines were adhered to flawlessly by the surgical and nursing teams.

Which of the following terms best classifies the patient's development of a pulmonary embolism in this scenario?

A consultation-liaison psychiatry service is evaluating four different patients on the medical-surgical wards to determine their capacity to refuse recommended interventions. Match each patient's clinical presentation with the specific core element of decision-making capacity (Appelbaum criteria) that is fundamentally impaired.

A hospital safety committee is reviewing an incident report filed by a clinical pharmacist. The hospital recently instituted a mandatory dual-verification electronic hard-stop for all customized epidural analgesic compounding. During a high-volume night shift with sudden staffing shortages, the pharmacist received an urgent order for an epidural infusion for a patient in precipitous labor experiencing severe distress. Unable to locate a second provider for verification after 15 minutes of attempting to page the on-call supervisor, the pharmacist utilized an emergency override code to bypass the hard-stop, compounded the medication alone, and dispensed it to avoid further delaying patient care. The medication was administered without any adverse effects. The pharmacist proactively submitted an incident report detailing the protocol deviation. According to Just Culture principles, which of the following is the most appropriate approach to addressing this pharmacist's action?

A 72-year-old male is admitted to the cardiology service following a syncopal episode. Echocardiography reveals severe, symptomatic aortic stenosis. The structural heart team recommends a transcatheter aortic valve replacement (TAVR). The patient, who has a history of Parkinson disease complicated by medication-induced psychosis, adamantly refuses the procedure. He claims that the physicians are federal agents attempting to implant a tracking device in his chest. The clinical team must navigate his refusal of care.

Arrange the following steps in the most appropriate chronological sequence for ethically and legally managing this patient's medical decision-making process.

During a weekly journal club, an attending physician presents a recently published multicenter, double-blind trial evaluating a novel monoclonal antibody for the prevention of severe asthma exacerbations. The trial enrolled 2,000 patients, who were assigned in a 1:1 ratio to receive either the new drug or a placebo.

Over a 1-year follow-up period, 150 patients in the placebo group experienced a severe exacerbation, compared to 107 patients in the treatment group. The $95\%$ confidence interval for the absolute risk reduction was reported as $0.015$ to $0.071$.

The attending states: "This drug is highly effective. It reduces the risk of exacerbations by roughly $29\%$. Therefore, we only need to treat 4 patients to prevent one severe exacerbation. Furthermore, the results are statistically significant because the confidence interval for the risk difference is entirely above zero."

Which of the following statements accurately identifies the true Number Needed to Treat (NNT) and the primary conceptual error made by the attending?

Match each epidemiological scenario described below with the most appropriate measure of disease frequency or mortality metric it calculates.

A resident physician is preparing to discharge an 82-year-old man to a skilled nursing facility (SNF) following a 7-day hospitalization for a non-ST elevation myocardial infarction. During the hospital stay, the patient was initiated on a new regimen of dual antiplatelet therapy (DAPT) and weight-based insulin glargine for newly diagnosed type 2 diabetes mellitus. The resident completes a comprehensive electronic discharge summary, prints a physical copy for the transport team to take with the patient, and securely faxes the final medication reconciliation list to the SNF. The resident then informs the attending physician, "All the discharge paperwork is complete, and the receiving facility has his medical records. I will sign the formal discharge order now." Which of the following is the most appropriate action for the attending physician to take regarding this transition of care?