Preventive Medicine and Public Health

A biostatistics consulting board is evaluating various research proposals submitted by investigators to ensure methodological rigor. For each proposed research methodology described below, determine the specific study design being utilized.

An establishment of care visit is scheduled for a 38-year-old female patient with a history of severe rheumatoid arthritis. Her joint disease is currently well controlled on a regimen of methotrexate and etanercept. She reports feeling well with no acute symptoms. Her family history is significant for colorectal cancer in her father, who was diagnosed at age 46. Social history reveals she is a former smoker, having quit 5 years ago after accumulating a 10 pack-year history. Her gynecological records indicate her most recent cervical cytology and high-risk human papillomavirus (hrHPV) co-testing was performed 4 years ago with negative results. Her immunization log reveals a Tdap vaccination 12 years ago. Recent serology confirms she is negative for varicella IgG antibodies, and she has no clinical history of chickenpox. During the consultation, she expresses concern about undiagnosed malignancies and asks whether a serum tumor marker test would be appropriate to screen for ovarian cancer. Physical examination and vital signs today are unremarkable. Which of the following sets of preventive and screening measures is most indicated for this patient at this time?

An 18-month-old boy is evaluated at the pediatric clinic for a scheduled health maintenance visit. He was diagnosed with polyarticular juvenile idiopathic arthritis at age 12 months, and his disease is currently well-controlled on a regimen of weekly methotrexate and scheduled infliximab infusions. Due to his initial prolonged illness and hospitalization, he did not receive his routine 12-month or 15-month immunizations. His mother mentions that he currently has mild, clear rhinorrhea and a low-grade temperature of 37.8°C (100.0°F) that started yesterday. She also notes he had a brief episode of audible wheezing during a similar mild cold last month, which completely resolved with supportive care in three days. The mother expresses anxiety about his development; she observes that he can walk up steps with one hand held, scribbles spontaneously with a crayon, and uses 12 distinct single words, but he is not yet combining words into two-word phrases. Vital signs and physical examination today are unremarkable aside from mild nasal congestion. Which of the following is the most appropriate next step in this patient's management?

Match each clinical vignette demonstrating a diagnostic error to the specific cognitive bias it best represents.

Match each clinical research scenario with its accurately calculated epidemiological measure.

To evaluate the efficacy of a novel sodium-glucose cotransporter-2 (SGLT2) inhibitor in preventing cardiovascular mortality, a multicenter, double-blind trial enrolls patients with chronic heart failure. Participants are randomly assigned to receive either the SGLT2 inhibitor or a placebo. After a median follow-up of three years, the data are analyzed. Among the $2,000$ patients in the intervention group, $240$ experienced a cardiovascular mortality event. In the control group, which also consisted of $2,000$ patients, $320$ experienced a cardiovascular mortality event. Based on these findings, what is the number needed to treat to prevent one cardiovascular mortality event over the study period?

Match each epidemiological research scenario with the specific type of bias or confounding it best represents.

Match each epidemiological scenario or study result with the specific research concept (bias or confounding) it best illustrates.

A research group conducts a randomized, double-blind, placebo-controlled trial to evaluate the efficacy of a novel biologic agent for patients with severe, treatment-resistant rheumatoid arthritis. The study's primary endpoint is the proportion of patients achieving clinical remission at $6$ months. During the trial design phase, the researchers determine that $500$ patients are required to achieve $80\%$ power to detect a $10\%$ absolute difference in remission rates, with an $\alpha$ level of $0.05$. The trial ultimately enrolls $500$ patients; however, due to unforeseen logistical challenges during the study period, $35\%$ of the enrolled participants are lost to follow-up and excluded from the final primary analysis. The final results show a $9\%$ absolute higher remission rate in the treatment group compared to the placebo group, with a $p$-value of $0.07$ and a $95\%$ confidence interval for the difference ranging from $-1\%$ to $+19\%$. Which of the following best explains why the trial failed to demonstrate a statistically significant benefit for the novel biologic agent?

Match each infectious disease presentation to the most appropriate mandatory public health action or infection control protocol.

Public health officials review data from a large population registry to investigate the relationship between residential proximity to major highways and the development of childhood asthma. An initial unadjusted analysis reveals a relative risk of 2.1 (95% CI: 1.6-2.8) for asthma in children living within 100 meters of a highway compared to those living farther away. The researchers subsequently conduct a stratified analysis based on household income levels. The relative risk for asthma among children in low-income households is 1.1 (95% CI: 0.8-1.4), and the relative risk among children in high-income households is 1.2 (95% CI: 0.9-1.5). Which of the following epidemiologic phenomena best explains the discrepancy between the initial and stratified findings?

Match each clinical research scenario with the most appropriate epidemiologic study design.

A randomized, double-blind, placebo-controlled trial evaluates a new calcitonin gene-related peptide (CGRP) antagonist for the prevention of chronic migraines. A total of 1,000 adult patients with a history of chronic migraines are enrolled and randomized in a 1:1 ratio to receive either the CGRP antagonist or a matched placebo. The primary study endpoint is the proportion of patients achieving at least a 50% reduction in monthly migraine days over a 12-week period.

At the conclusion of the 12-week study, the following results are reported:
- Placebo group: 150 out of 500 patients met the primary endpoint.
- Treatment group (CGRP antagonist): 275 out of 500 patients met the primary endpoint.

The findings are determined to be statistically significant ($p < 0.01$). Based on these trial results, what is the number needed to treat (NNT) to achieve the primary endpoint in one additional patient? (Provide the exact whole number).

An academic medical center evaluates a new electronic health record (EHR) alert designed to reduce inappropriate broad-spectrum antibiotic prescriptions for uncomplicated acute bronchitis. The researchers conduct a prospective, randomized controlled trial by randomizing $N = 40$ outpatient physicians to either the EHR alert group or the standard workflow group. Over six months, the data show that physicians in the intervention group had an 18% greater reduction in broad-spectrum antibiotic prescriptions compared to the control group. Statistical analysis yields a $p$-value of 0.11 and a 95% confidence interval of -38% to +2%. The researchers conclude that the EHR alert does not significantly reduce prescription rates. Which of the following best explains why the study failed to demonstrate statistical significance despite a potentially meaningful clinical difference?

A $12$-month-old boy is brought to the clinic for a routine well-child examination. He was diagnosed with perinatal human immunodeficiency virus (HIV) infection and is currently receiving antiretroviral therapy. His mother reports he has had a mild cough and rhinorrhea for the past $2$ days. On physical examination, his temperature is $37.8^\circ\text{C}$ ($100.0^\circ\text{F}$), pulse is $120/\text{min}$, and respirations are $32/\text{min}$. Lung auscultation reveals diffuse bilateral wheezing and mild crackles without increased work of breathing. When asked about his behavior, the mother is concerned because he only specifically says 'mama' and 'dada' and stands alone but cannot walk independently. Recent laboratory results show a CD4+ T-cell percentage of $12\%$. His immunizations are up to date through the $6$-month schedule. Which of the following is the most appropriate next step in management for this patient?

Occupational medicine requires identifying specific toxic environmental exposures based on their unique pathophysiological manifestations. Match each occupational or environmental exposure with its most characteristic clinical, laboratory, or imaging finding.

Evaluate the following distinct patient scenarios detailing upcoming international travel plans and occupational exposures. Match each patient's clinical and travel profile with the most critical, specific immunization indicated for their itinerary according to current CDC/ACIP guidelines.

A 5-year-old girl is brought to the pediatrician by her parents due to a potential varicella exposure. Yesterday, she spent 4 hours playing indoors with her 6-year-old cousin, who subsequently developed a low-grade fever and a diffuse vesicular rash earlier today. The cousin has just been diagnosed with chickenpox. The patient has a history of acute lymphoblastic leukemia, diagnosed one year ago, and she is currently on a maintenance chemotherapy regimen consisting of daily 6-mercaptopurine and weekly methotrexate. A review of her immunization registry shows she completed all routine infancy vaccines, including her first doses of the measles-mumps-rubella and varicella vaccines at 12 months of age. No further vaccines have been administered since her cancer diagnosis. The patient feels well today, and her physical examination is completely normal. Which of the following is the most appropriate next step in the management of this patient?

A $6$-year-old girl is evaluated in the pediatric rheumatology clinic for a routine follow-up. Six months ago, she was diagnosed with systemic juvenile idiopathic arthritis. She is currently maintained on high-dose daily oral prednisone ($2$ mg/kg/day) and methotrexate. Her disease has been well-controlled on this regimen. Review of her medical chart shows that she received all recommended immunizations during her first two years of life, but she has not attended any preventive care visits since then. It is mid-October. Vital signs and physical examination today are unremarkable. Which of the following vaccines can be safely administered to this patient today? (Select all that apply)

Researchers at a medical center are investigating a potential association between the use of a newly introduced class of weight-loss medications and the development of acute pancreatitis. To conduct the study, they review electronic health records to identify 150 patients who were admitted to the hospital with a confirmed diagnosis of acute pancreatitis over the past three years. They also randomly select 600 patients from the same hospital system who have never been diagnosed with acute pancreatitis, ensuring they are matched by age, sex, and body mass index. The research team then analyzes the past pharmacy dispensing records for all 750 individuals to determine how many had been prescribed the new weight-loss medication prior to the index date. Which of the following is the most appropriate statistical measure to report the strength of the association in this study?