Post-Quiz: Biostatistics

A pharmaceutical company has conducted a study to test the efficacy of a new anti-diabetic drug. The mean reduction in HbA1c levels recorded in the study population (n=100) was found to be 1.5 ± 0.3%. The 95% Confidence Interval (CI) for the mean reduction of HbA1c levels within this population was calculated to be (1.3%, 1.7%). What is the appropriate conclusion based on this interval?

A multicenter clinical trial aims to assess the efficacy of a novel antihypertensive agent in lowering systolic blood pressure among geriatric patients with multiple comorbidities, including diabetes mellitus, hyperlipidemia, depression, and obstructive sleep apnea. The study plans to recruit participants who are 60 years or older.

Which of the following elements poses the most significant risk for bias in the study design of this clinical trial?

A medical student is asking about the interpretation of test results for a new HIV screening test that is being evaluated in a study. The new test is being compared to the gold standard of PCR detection of HIV RNA. The study population included 1,000 patients, with the following test results:

850 HIV-negative patients had a negative screening test result

30 HIV-negative patients had a positive screening test result

100 HIV-positive patients had a positive screening test result

20 HIV-positive patients had a negative screening test result

What change in the test population would be most likely to increase the negative predictive value of the new HIV screening test?

A pharmaceutical company has conducted a study to test the efficacy of a new anti-diabetic drug. The mean reduction in HbA1c levels recorded in the study population (n=100) was found to be 1.5 ± 0.3%. The 95% Confidence Interval (CI) for the mean reduction of HbA1c levels within this population was calculated to be (1.3%, 1.7%). What is the appropriate conclusion based on this interval?

A study investigated the safety and effectiveness of two medications, A and B, in the treatment of a specific disease. Medication A has an NNT of 10 and a lower risk of adverse effects compared to medication B, which has an NNT of 20. Which medication would be the better choice for a patient who is at a higher risk for adverse effects?

A 75-year-old male patient with hypertension participates in a randomized controlled trial evaluating the efficacy of a new antihypertensive medication in reducing systolic blood pressure. The patient’s systolic blood pressure increases despite being compliant with the medication regimen and not reporting any adverse effects. The study team suspects that there may be a source of confounding affecting the patient’s response to the new medication. What is the most likely source of confounding in this trial?

A randomized controlled trial was conducted to evaluate the effectiveness of a new antihypertensive medication. The participants were randomly assigned to either receive the new medication (Group A) or a placebo (Group B). To determine the efficacy of the new medication, blood pressure readings were taken before and after the start of treatment. Which of the following biostatistical tests is most appropriate to compare the mean blood pressure changes between the two groups?

A clinical trial is conducted to determine the effectiveness of a new drug in treating hypertension. The study compares the mean blood pressure reduction in two groups of patients: one group receives treatment A (the new drug) and the other group receives treatment B (standard therapy). The null hypothesis (H0) states there is no difference between the groups. The trial results provide enough evidence to reject H0. Which of the following conclusions is accurate?

A 71-year-old man with type 2 diabetes is enrolled in a clinical trial for a new breath test designed to measure chronic blood glucose control. The test aims to predict patients’ hemoglobin A1c levels based on a metabolite detected in the breath. During 1 day, the patient performs the test 5 times with the following results: 9.2%, 9.4%, 8.9%, 9.1%, and 9.3%. If this patient’s true A1c is 6.8%, what is the most appropriate conclusion about the new breath test based on these results?

A clinical trial is conducted to evaluate the effectiveness of a new antihypertensive drug. The trial involves 1000 patients, 500 of whom are given the new drug (Group A) and 500 who are given a placebo (Group B). At the end of the trial, 100 patients in Group A and 200 patients in Group B developed hypertension. What is the relative risk (RR) of developing hypertension for patients in Group A compared to Group B?