All practice questions

A 72-year-old man presents to the urology clinic with a one-week history of painless gross hematuria. He has a 40-pack-year smoking history. Vital signs are within normal limits, and physical examination is unremarkable. Office flexible cystoscopy reveals a completely normal bladder mucosa and urethra. Urine cytology returns positive for high-grade malignant cells. Arrange the following interventions in the correct chronological order for the definitive evaluation and management of this patient's condition.

A prospective cohort study is conducted to evaluate the association between a diet high in ultra-processed foods and the development of colorectal cancer. The investigators enroll 50,000 healthy adults aged 45 to 60 years. At baseline, participants complete detailed dietary questionnaires and are categorized based on their dietary patterns. The high ultra-processed food (UPF) consumption group includes 10,000 participants, while the low UPF consumption group includes 40,000 participants.

All participants are followed for 15 years. During the follow-up period, 400 incident cases of colorectal cancer are diagnosed among the participants in the high UPF group. In the low UPF group, 400 incident cases of colorectal cancer are diagnosed.

Based on the study results, what percentage of the colorectal cancer cases among the participants with high ultra-processed food consumption is attributable to their high UPF diet?

A 62-year-old man is admitted to the hospital with a deep vein thrombosis and is started on a continuous heparin infusion. The following morning, a nurse inadvertently administers a vial of intravenous insulin instead of heparin. The error occurred because the two medication vials are similar in size and color and were stored in adjacent bins in the automated dispensing cabinet. The patient develops hypoglycemia but is quickly stabilized with intravenous dextrose. The hospital administration is notified of this adverse event. Which of the following is the most appropriate next step to address this incident?

A university hospital conducts a randomized controlled trial to evaluate the efficacy of a new oral anticoagulant compared to standard therapy for the prevention of deep vein thrombosis (DVT) following total knee arthroplasty. The trial enrolls 1,200 patients, who are randomly assigned in a 1:1 ratio to either the new oral anticoagulant or standard therapy. The results over a 90-day postoperative follow-up period are presented in the table below:

Based on these data, how many patients need to be treated with the new oral anticoagulant instead of standard therapy to prevent one additional case of DVT?

A $24$-year-old man is brought to the emergency department after falling off his skateboard and striking the right side of his head. Witnesses report he had a brief loss of consciousness lasting approximately $1$ minute, followed by a period where he was awake and conversing. En route to the hospital, he became progressively lethargic and unresponsive. On arrival, his blood pressure is $170/95$ mmHg, heart rate is $52$/min, and respirations are $10$/min and irregular. His Glasgow Coma Scale score is $6$ (Eye: $1$, Verbal: $2$, Motor: $3$ with abnormal flexion). Physical examination reveals a right pupil that is $7$ mm and nonreactive to light, as well as left-sided hemiparesis. Arrange the following management steps in the most appropriate chronological sequence for this patient.

A 65-year-old man is evaluated in the clinic after a routine chest radiograph, obtained prior to an elective inguinal hernia repair, incidentally revealed a widened mediastinum and an enlarged aortic contour. He has a history of essential hypertension and a 40-pack-year smoking history but currently feels well, reporting no chest, abdominal, or back pain. His blood pressure is 148/92 mm Hg, and his heart rate is 78/min. Arrange the following steps in the most appropriate chronological order for the definitive evaluation and long-term management of this patient's suspected condition.

Match each clinical presentation of a pancreatic fluid collection or cystic lesion with its correct diagnosis and most appropriate surgical management step.

A 54-year-old woman is treated in the intensive care unit for urosepsis. Blood cultures eventually grow *Escherichia coli* that is susceptible to narrow-spectrum cephalosporins. Despite these final culture and susceptibility results being uploaded to the electronic medical record, the covering physician maintains the patient on broad-spectrum piperacillin-tazobactam and vancomycin for an additional four days. The patient subsequently develops severe diarrhea and is diagnosed with a *Clostridioides difficile* infection. The hospital's quality improvement committee reviews this adverse event to improve future patient care. Which of the following is the most appropriate systemic intervention to prevent similar events?

A tropical medicine clinic is evaluating symptomatic patients for a localized outbreak of a novel parasitic infection. The prevalence of the infection among symptomatic patients presenting to this clinic is $20\%$.

Two independent rapid diagnostic point-of-care tests have been developed to detect the pathogen. They utilize entirely different biological mechanisms: Test A detects a surface glycoprotein antigen, while Test B detects a unique metabolic byproduct. Because they do not cross-react, their performance characteristics are statistically independent for both infected and uninfected individuals.

The performance characteristics of the two tests are as follows:
* Test A: Sensitivity = $80\%$, Specificity = $90\%$
* Test B: Sensitivity = $90\%$, Specificity = $80\%$

A patient presents with symptoms and is tested using BOTH assays simultaneously. Both Test A and Test B return a POSITIVE result.

Based on these results, what is the probability (expressed as a percentage) that the patient actually has the infection?

A hospital safety committee is reviewing a recent sentinel event in which a patient received an incorrect dose of a high-risk medication due to a misprogrammed infusion pump. The hospital administration initiates a formal root cause analysis (RCA) to investigate the incident and prevent future occurrences. Arrange the following fundamental steps of a root cause analysis in the correct chronological order of execution.

A 66-year-old woman comes to the clinic to establish primary care. She recently moved to the area and has not seen a physician in over 5 years. She feels well and has no acute complaints. She takes no daily medications and has no chronic medical conditions. She went through menopause at age 51 and explicitly denies any postmenopausal bleeding. She has never smoked and consumes alcohol socially. She reports having a normal screening colonoscopy 4 years ago and a normal screening mammogram 6 months ago. Her blood pressure is 118/76 mm Hg, and body mass index is 23 kg/m². Physical examination is unremarkable. According to current preventive care guidelines, which of the following is the most appropriate next step in the care of this patient?

An occupational health clinic at a multinational manufacturing corporation routinely screens its employees for latent tuberculosis infection using an interferon-gamma release assay. Historically, the clinic only screened employees relocating from regions with highly endemic tuberculosis, where the estimated disease prevalence is $25\%$. A new corporate directive mandates that all employees, including those from regions where the prevalence is estimated at $0.5\%$, must now undergo identical screening. Assuming the inherent diagnostic accuracy of the assay remains constant, which of the following changes in test performance characteristics is most likely to occur when screening the low-endemic employee population compared to the high-endemic population?

A $32$-year-old man is evaluated in the surgical intensive care unit for severe right lower extremity pain. $12$ hours ago, he underwent closed reduction and intramedullary nailing for a comminuted right tibial shaft fracture sustained in a high-speed skiing accident. He reports that the pain has progressively worsened over the last $3$ hours and is now "unbearable," describing it as a deep, burning ache. The pain is completely unresponsive to multiple doses of intravenous morphine. His temperature is $37.4^\circ\text{C}$ ($99.3^\circ\text{F}$), blood pressure is $148/92 \text{ mmHg}$, pulse is $118/\text{min}$, and respiratory rate is $22/\text{min}$. On physical examination, the right leg is tensely swollen, shiny, and exceedingly firm to palpation. Passive plantar flexion of the right ankle and toes elicits excruciating pain. Sensation to light touch is markedly decreased over the first dorsal web space of the right foot. The dorsalis pedis and posterior tibial pulses are palpable and symmetric to the contralateral side. Which of the following is the most appropriate next step in management?

An investigator is evaluating a new transdermal hormonal contraceptive for its association with venous thromboembolism (VTE) in women of reproductive age. Initial overall analysis reveals that women using the transdermal patch have a relative risk (RR) of 4.2 for developing VTE compared to non-users. The research team suspects that an underlying genetic predisposition might alter this relationship. They subsequently divide the cohort based on the presence or absence of the prothrombin G20210A mutation. Among participants who carry the mutation, the relative risk of VTE in transdermal patch users compared to non-users is 15.5. Among participants who do not carry the mutation, the relative risk is 2.1. Both stratified findings are statistically significant. Which of the following epidemiological concepts best describes the role of the prothrombin G20210A mutation in this scenario?

A 42-year-old woman is brought to the emergency department due to a 6-hour history of acute-onset, severe, colicky periumbilical pain that radiates to her back. She also reports multiple episodes of bilious vomiting. Her medical history is significant for morbid obesity treated with a laparoscopic Roux-en-Y gastric bypass 4 years ago, after which she lost 45 kg (100 lb). Current medications include a multivitamin and calcium supplementation. Her temperature is 37.1°C (98.8°F), blood pressure is 105/65 mm Hg, pulse is 118/min, and respirations are 20/min. Physical examination reveals a non-distended, soft abdomen with moderate periumbilical tenderness. There is no rebound tenderness or involuntary guarding. Bowel sounds are hyperactive. Laboratory studies show a leukocyte count of 12,500/mm³ and serum lactate of 2.1 mmol/L. A CT scan of the abdomen and pelvis with intravenous contrast demonstrates a cluster of dilated small bowel segments in the left upper quadrant, stretching and engorgement of the mesenteric vessels, and a small amount of interloop free fluid. Which of the following is the most appropriate next step in management of this patient?

A 55-year-old man with average risk for colorectal cancer opts for noninvasive screening at his annual wellness visit. Arrange the following clinical steps in the correct chronological order for his preventive care and subsequent management, assuming his initial screening test is positive and reveals advanced adenomas.

A $34$-year-old woman is brought to the emergency department due to the sudden onset of severe, continuous periumbilical pain that radiates to her back. The pain started $4$ hours ago and is accompanied by intractable nausea and multiple episodes of bilious vomiting. Two years ago, she underwent an uncomplicated laparoscopic Roux-en-Y gastric bypass for morbid obesity, achieving a $50$-kg ($110$-lb) weight loss. Vital signs are temperature $38.3^\circ\text{C}$ ($100.9^\circ\text{F}$), heart rate $124/\text{min}$, blood pressure $88/56\text{ mm Hg}$, and respirations $22/\text{min}$. Physical examination reveals a slightly distended, rigid abdomen with diffuse guarding and marked rebound tenderness. Bowel sounds are absent. Laboratory studies show a leukocyte count of $18,500/\text{mm}^3$ and a serum lactate of $4.8\text{ mmol/L}$. An upright chest radiograph shows no free air under the diaphragm. Which of the following is the most appropriate next step in management?

A 68-year-old man presents to the emergency department with a 5-day history of progressively worsening mid-back pain. He reports that over the past 24 hours, his legs have felt "heavy" and he has had difficulty walking. He also mentions not having a bowel movement in 3 days and experiencing difficulty initiating urination. His medical history is significant for advanced prostate cancer diagnosed 2 years ago. His temperature is 37.1°C (98.8°F), blood pressure is 145/90 mm Hg, and pulse is 82/min. Neurologic examination reveals 3/5 strength in the bilateral lower extremities. Muscle tone is increased in the lower limbs, and deep tendon reflexes are 3+ at the knees and ankles. Plantar reflexes are upgoing bilaterally. Perianal sensation is decreased. Which of the following is the most appropriate next step in management?

A 42-year-old male agricultural worker is brought to the emergency department by his coworkers due to sudden onset of severe shortness of breath, excessive salivation, and abdominal cramps. His coworkers report he was spraying fields with organophosphate pesticides without wearing appropriate personal protective equipment. On physical examination, his heart rate is 50/min, respiratory rate is 26/min, and blood pressure is 100/60 mm Hg. He has pinpoint pupils, generalized muscle fasciculations, and diffuse wheezing with rhonchi on lung auscultation. Which of the following are the most appropriate next steps in the pharmacological management of this patient's condition? (Select all that apply)

A team of clinical researchers is designing a retrospective cohort study to investigate the association between long-term proton pump inhibitor (PPI) therapy and the development of chronic kidney disease in adults over the age of 65. During the initial planning stages, the research committee raises concerns about concurrent nonsteroidal anti-inflammatory drug (NSAID) use. NSAIDs are independently associated with renal impairment and are frequently prescribed to patients taking PPIs for gastrointestinal protection. The researchers want to proactively address this variable before any data collection begins.

Which of the following methodological techniques can be implemented during the design phase of this observational study to minimize the effect of concurrent NSAID use? (Select all that apply)