FPGEE Drug Information 3 — Questions and Answers
Question 1: Which section of a clinical trial report details how participants were enrolled and the characteristics of the study population?
- Methods (Correct answer)
- Results
- Discussion
- Abstract
Correct answer: Methods
The Methods section describes study design, enrollment criteria, population characteristics, and how the trial was conducted.
Question 2: A study reports an NNT (Number Needed to Treat) of 10. What does this mean?
- 10% of patients will respond to treatment
- 10 patients must be treated for 1 patient to benefit (Correct answer)
- The drug costs 10 times more than placebo
- The study enrolled 10 patients per arm
Correct answer: 10 patients must be treated for 1 patient to benefit
NNT of 10 means 10 patients must receive treatment for one additional patient to experience the defined benefit compared to control.
Question 3: Which statistical measure describes the ratio of risk in the treatment group compared to the control group?
- Absolute risk reduction (ARR)
- Relative risk (RR) (Correct answer)
- Number needed to harm (NNH)
- Confidence interval (CI)
Correct answer: Relative risk (RR)
Relative risk (RR) is the ratio of the probability of an outcome in the treatment group to the probability in the control group.
Question 4: What is the primary purpose of blinding in a randomized controlled trial?
- To reduce the sample size needed
- To prevent selection bias in enrollment
- To reduce performance and detection bias (Correct answer)
- To increase statistical power
Correct answer: To reduce performance and detection bias
Blinding prevents performance bias (changes in participant/provider behavior) and detection bias (differential outcome assessment) from affecting results.
Question 5: A 95% confidence interval for a drug's effect on blood pressure is -8 to -2 mmHg. What can be concluded?
- There is a 95% probability the true effect is between -8 and -2 mmHg
- The drug does not significantly lower blood pressure
- We can be 95% confident the drug lowers blood pressure (Correct answer)
- The drug raises blood pressure in 5% of patients
Correct answer: We can be 95% confident the drug lowers blood pressure
A 95% CI of -8 to -2 mmHg, entirely below zero, means we are 95% confident the drug significantly lowers blood pressure.
Question 6: Which type of bias occurs when patients who drop out of a clinical trial differ systematically from those who complete it?
- Allocation bias
- Attrition bias (Correct answer)
- Reporting bias
- Hawthorne effect
Correct answer: Attrition bias
Attrition bias occurs when the characteristics of participants who drop out differ from those who remain, potentially distorting results.
Question 7: Which study design provides the strongest evidence for establishing causality between a drug exposure and outcome?
- Case-control study
- Cross-sectional study
- Randomized controlled trial (Correct answer)
- Retrospective cohort study
Correct answer: Randomized controlled trial
Randomized controlled trials (RCTs) provide the strongest evidence for causality because randomization controls for known and unknown confounders.
FPGEE Drug Information 3
Which section of a clinical trial report details how participants were enrolled and the characteristics of the study population?