Maxemo EMREE 26-27
A 19y/o M presents with fever, severe fatigue, and exudative pharyngitis. O/E: Posterior cervical lymphadenopathy. Monospot test is positive. Regarding primary prevention for this condition, which statement is correct?
💡 EXPLANATION:
The diagnosis is Infectious Mononucleosis (EBV), indicated by the triad of fever, pharyngitis, and lymphadenopathy with a positive Monospot. Unlike many other viral illnesses, no vaccine is currently licensed for the prevention of EBV.
A 62y/o M with T2DM and prior MI presents for follow-up. HbA1c 7.5%, eGFR 70 mL/min. Empagliflozin is added to his regimen to reduce cardiovascular mortality. Which mechanism primarily mediates this cardioprotective effect?
Anonymous Quiz
14%
Enhancement of insulin sensitivity
18%
Suppression of glucagon secretion
18%
Inhibition of DPP-4 enzyme
50%
Osmotic diuresis via glycosuria
Maxemo EMREE 26-27
A 62y/o M with T2DM and prior MI presents for follow-up. HbA1c 7.5%, eGFR 70 mL/min. Empagliflozin is added to his regimen to reduce cardiovascular mortality. Which mechanism primarily mediates this cardioprotective effect?
💡 EXPLANATION:
Empagliflozin is an SGLT2 inhibitor indicated for T2DM with established ASCVD. It acts by blocking glucose reabsorption in the proximal tubule, causing glycosuria. This leads to osmotic diuresis/natriuresis, reducing intravascular volume, preload, and afterload.
Researchers investigate the link between fire retardants and interstitial lung disease (ILD). They select 50 patients with ILD and 50 healthy matched controls to assess past exposure history. What is the most appropriate study design classification?
Anonymous Quiz
47%
Case-control study
32%
Retrospective cohort study
16%
Cross-sectional study
5%
Randomized controlled trial
Maxemo EMREE 26-27
Researchers investigate the link between fire retardants and interstitial lung disease (ILD). They select 50 patients with ILD and 50 healthy matched controls to assess past exposure history. What is the most appropriate study design classification?
💡 EXPLANATION:
Participants were selected based on their disease status (ILD vs. no ILD) to look back at prior exposures. This directionality (Outcome → Exposure) is the defining characteristic of a Case-control study.
A study shows that patients screened for glioblastoma appear to survive longer than those diagnosed after symptom onset, despite no actual prolongation of life or change in disease course. Which bias best explains this result?
Anonymous Quiz
15%
Selection bias
30%
Length-time bias
55%
Lead-time bias
0%
Confounding bias
Maxemo EMREE 26-27
A study shows that patients screened for glioblastoma appear to survive longer than those diagnosed after symptom onset, despite no actual prolongation of life or change in disease course. Which bias best explains this result?
💡 EXPLANATION:
Lead-time bias occurs when screening detects a disease earlier than clinical presentation, artificially increasing the measured survival time (duration from diagnosis to death) without actually changing the time of death or improving outcomes.
A study finds that patients diagnosed with glioblastoma via screening MRI have a 6-week longer average survival compared to those diagnosed after symptom onset. Which type of bias most likely accounts for this difference?
Anonymous Quiz
0%
Selection bias
43%
Length-time bias
48%
Lead-time bias
10%
Confounding bias
Maxemo EMREE 26-27
A study finds that patients diagnosed with glioblastoma via screening MRI have a 6-week longer average survival compared to those diagnosed after symptom onset. Which type of bias most likely accounts for this difference?
💡 EXPLANATION:
Lead-time bias occurs when screening detects a disease earlier in its natural history than it would have presented clinically. This artificially increases the perceived survival duration (diagnosis to death) without extending actual lifespan.
An RCT of 1600 obese patients compares orlistat vs lifestyle. At the end, 120 participants had dropped out: 97 from the lifestyle arm and 23 from the combination arm. Which bias most threatens the study's validity?
Anonymous Quiz
6%
Selection bias
28%
Measurement bias
67%
Attrition bias
0%
Recall bias
Maxemo EMREE 26-27
An RCT of 1600 obese patients compares orlistat vs lifestyle. At the end, 120 participants had dropped out: 97 from the lifestyle arm and 23 from the combination arm. Which bias most threatens the study's validity?
💡 EXPLANATION:
Attrition bias arises from differential loss to follow-up between study arms. The unequal dropout rate (97 vs 23) undermines randomization and threatens internal validity, as dropouts may differ systematically from those who complete the study.
A dataset of 37 newborn weights has a mean, median, and mode of 3.23 kg. A 38th newborn weighing 4.59 kg is added to the group. Which statement best describes the resulting change in central tendency?
Anonymous Quiz
6%
Mean decreases
12%
Mode increases
47%
Median increases more than mean
35%
Mean increases, mode unchanged
Maxemo EMREE 26-27
A dataset of 37 newborn weights has a mean, median, and mode of 3.23 kg. A 38th newborn weighing 4.59 kg is added to the group. Which statement best describes the resulting change in central tendency?
💡 EXPLANATION:
Adding a large outlier (4.59 kg > 3.23 kg) creates a positive skew. The mean is sensitive to outliers and increases. The median shifts slightly upward but less than the mean. The mode is robust and remains unchanged by a single new value.
A smoking cessation trial experiences a high dropout rate among heavy smokers. Analysis restricted to the remaining participants reveals significantly inflated treatment efficacy. Which type of bias is most likely responsible for this finding?
Anonymous Quiz
6%
Selection bias
12%
Recall bias
24%
Observer bias
59%
Attrition bias
Maxemo EMREE 26-27
A smoking cessation trial experiences a high dropout rate among heavy smokers. Analysis restricted to the remaining participants reveals significantly inflated treatment efficacy. Which type of bias is most likely responsible for this finding?
💡 EXPLANATION:
Attrition bias occurs when participants lost to follow-up differ systematically from those who remain. In this case, the loss of heavy smokers leaves a cohort of highly motivated participants, leading to an overestimation of the treatment's true effect.
A 10-year epidemiological study on Primary Biliary Cholangitis reveals a significant increase in prevalence despite a stable incidence rate. What is the most likely explanation for this observation?
Anonymous Quiz
0%
Increased mortality rate
67%
Improved patient survival
20%
Increased cure rate
13%
Reduced diagnostic sensitivity
Maxemo EMREE 26-27
A 10-year epidemiological study on Primary Biliary Cholangitis reveals a significant increase in prevalence despite a stable incidence rate. What is the most likely explanation for this observation?
💡 EXPLANATION:
Prevalence (P) roughly equals Incidence (I) × Duration (D). With stable incidence, increased prevalence is caused by increased disease duration. Improved quality of care extends patient survival, accumulating more existing cases over time.
A cardiologist performs a hospital-based case-control study on MI and malignancy. To minimize Berkson's bias (admission rate bias) inherent in this setting, which strategy is most effective?
Anonymous Quiz
35%
Select controls from the community
29%
Match participants by age and gender
24%
Increase the study sample size
12%
Blind the researchers to outcomes
Maxemo EMREE 26-27
A cardiologist performs a hospital-based case-control study on MI and malignancy. To minimize Berkson's bias (admission rate bias) inherent in this setting, which strategy is most effective?
💡 EXPLANATION:
Berkson's bias is a selection bias occurring when hospital admission rates differ between cases and controls. It causes spurious associations in hospital-based studies. Using community-based controls avoids admission-related selection factors, minimizing this bias.