Ethics/Biostatistics Practice Questions

Question 1

A research team develops a new monoclonal antibody checkpoint inhibitor for advanced melanoma that has shown promise in animal studies as well as high efficacy and low toxicity in early phase human clinical trials. The research team would now like to compare this drug to existing standard of care immunotherapy for advanced melanoma. The research team decides to conduct a non-randomized study where the novel drug will be offered to patients who are deemed to be at risk for toxicity with the current standard of care immunotherapy, while patients without such risk factors will receive the standard treatment. Which of the following best describes the level of evidence that this study can offer?

Accepted Answer

Level 3

Answer

Level 1

Answer

Level 5

Answer

Level 4

Answer

Level 2

Question 2

An investigator for a nationally representative health survey is evaluating the heights and weights of men and women aged 18–74 years in the United States. The investigator finds that for each sex, the distribution of heights is well-fitted by a normal distribution. The distribution of weight is not normally distributed. Results are shown:
Mean Standard deviation
Height (inches), men 69 0.1
Height (inches), women 64 0.1
Weight (pounds), men 182 1.0
Weight (pounds), women 154 1.0
Based on these results, which of the following statements is most likely to be correct?

Accepted Answer

99.7% of heights in women are likely to fall between 63.7 and 64.3 inches.

Answer

86% of heights in women are likely to fall between 63.9 and 64.1 inches.

Answer

68% of weights in women are likely to fall between 153 and 155 pounds.

Answer

95% of heights in men are likely to fall between 68.85 and 69.15 inches.

Answer

99.7% of heights in men are likely to fall between 68.8 and 69.2 inches.

Question 3

A clinical trial investigating a new biomedical device used to correct congenital talipes equinovarus (club foot) in infants has recently been published. The study was a preliminary investigation of a new device and as such the sample size is only 20 participants. The results indicate that the new biomedical device is less efficacious than the current standard of care of serial casting (p < 0.001), but the authors mention in the conclusion that it may be due to a single outlier--a patient whose foot remained uncorrected by the conclusion of the study. Which of the following descriptive statistics is the least sensitive to outliers?

Accepted Answer

Median

Answer

Standard deviation

Answer

Mean

Answer

Variance

Answer

Mode

Question 4

An investigator is measuring the blood calcium level in a sample of female cross country runners and a control group of sedentary females. If she would like to compare the means of the two groups, which statistical test should she use?

Accepted Answer

t-test

Answer

Chi-square test

Answer

Linear regression

Answer

ANOVA (Analysis of Variance)

Answer

F-test

Question 5

A neuro-oncology investigator has recently conducted a randomized controlled trial in which the addition of a novel alkylating agent to radiotherapy was found to prolong survival in comparison to radiotherapy alone (HR = 0.7, p < 0.01). A number of surviving participants who took the alkylating agent reported that they had experienced significant nausea from the medication. The investigator surveyed all participants in both the treatment and the control group on their nausea symptoms by self-report rated mild, moderate, or severe. The investigator subsequently compared the two treatment groups with regards to nausea level.

| | Mild nausea | Moderate nausea | Severe nausea |
|---|---|---|---|
| Treatment group (%) | 20 | 30 | 50 |
| Control group (%) | 35 | 35 | 30 |

Which of the following statistical methods would be most appropriate to assess the statistical significance of these results?

Accepted Answer

Chi-square test

Answer

Pearson correlation coefficient

Answer

Multiple logistic regression

Answer

Unpaired t-test

Answer

Paired t-test

Question 6

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?

Accepted Answer

Test C on the entire student body followed by Test A on those who are positive

Answer

Test A on the entire student body followed by Test B on those who are positive

Answer

Test A on the entire student body followed by Test C on those who are positive

Answer

Test C on the entire student body followed by Test B on those who are positive

Answer

Test B on the entire student body followed by Test A on those who are positive

Question 7

A study is conducted to find an association between serum cholesterol and ischemic heart disease. Data is collected, and patients are classified into either the "high cholesterol" or "normal cholesterol" group and also into groups whether or not the patient experiences stable angina. Which type of data analysis is most appropriate for this study?

Accepted Answer

Chi-squared

Answer

Attributable risk

Answer

Analysis of variance

Answer

T-test

Answer

Pearson correlation

Question 8

A 52-year-old man presents to the office for a diabetes follow-up visit. He currently controls his diabetes through lifestyle modification only. He monitors his blood glucose at home with a glucometer every day. He gives the doctor a list of his most recent early morning fasting glucose readings from the past 8 days which are: 128 mg/dL, 130 mg/dL, 132 mg/dL, 125 mg/dL, 134 mg/dL, 127 mg/dL, 128 mg/dL, and 136 mg/dL. Which of the following values is the median of this data set?

Accepted Answer

129 mg/dL

Answer

132 mg/dL

Answer

128 mg/dL

Answer

127 mg/dL

Answer

130 mg/dL

Question 9

A 45-year-old man presents for his annual checkup. The patient has a past medical history of diabetes mellitus (DM) type 2 that is well-controlled with diet. In addition, he was admitted to this hospital 1-year ago for a myocardial infarction (MI). The patient reports a 40-pack-year smoking history. However, after his MI, his doctors informed him about how detrimental smoking was to his heart condition. Since then, he has made efforts to cut down and now, for the past seven months, has stopped smoking. He says he used to use smoking as a means of dealing with his work and family stresses. He now attends wellness sessions at work and meditates early every morning before the family wakes up. Which of the following stages of the transtheoretical model is this patient most likely in?

Accepted Answer

Maintenance

Answer

Preparation

Answer

Contemplation

Answer

Action

Answer

Precontemplation

Question 10

A 7-year-old girl presents for a follow-up visit after recent discharge from the hospital. She was admitted about 4 months ago for symptoms of seizures, altered mental status, and fever. She was diagnosed during that admission with herpes encephalitis and recovered well after being treated with acyclovir. However, at this visit, her parents complain of some “strange behaviors” that have developed over the past several weeks. For example, she seems to be snacking uncontrollably and eats significantly more than she did before. Her teacher has also sent home notes stating that she has been chewing on art supplies such as crayons and glue and that she has been sent to the principal twice for rubbing her genitals inappropriately during class. The pediatric neurologist decides to get a follow-up MRI. Which of the following parts of the brain is most likely to have abnormal findings?

Accepted Answer

Amygdala

Answer

Hippocampus

Answer

Brainstem

Answer

Lateral geniculate nucleus

Answer

Substantia nigra

Ethics/Biostatistics

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