CTA CTA Biostatistics & Study Design 1 — Questions and Answers
Question 1: Which type of clinical trial design randomly assigns participants to treatment or control groups to minimize bias?
- Observational study
- Randomized controlled trial (RCT) (Correct answer)
- Case-control study
- Cross-sectional study
Correct answer: Randomized controlled trial (RCT)
A randomized controlled trial (RCT) uses random assignment to treatment or control groups, which is the gold standard for minimizing selection bias in clinical research.
Question 2: In a double-blind clinical trial, who is unaware of the treatment assignment?
- Only the participant
- Only the investigator
- Both the participant and the investigator (Correct answer)
- Only the sponsor
Correct answer: Both the participant and the investigator
In a double-blind study, both the participant and the investigator are unaware of treatment assignments to prevent performance and detection bias.
Question 3: What is a Phase I clinical trial primarily designed to evaluate?
- Efficacy in a large patient population
- Safety and dosing in a small group of healthy volunteers (Correct answer)
- Long-term effectiveness compared to standard treatment
- Post-market surveillance of an approved drug
Correct answer: Safety and dosing in a small group of healthy volunteers
Phase I trials are the first human studies focused on assessing safety, tolerability, and pharmacokinetics in a small group, typically healthy volunteers.
Question 4: What does the term 'placebo-controlled' mean in a clinical trial?
- All participants receive the active drug
- A control group receives an inactive substance identical in appearance to the treatment (Correct answer)
- The trial uses historical data as a control
- Participants self-select their treatment group
Correct answer: A control group receives an inactive substance identical in appearance to the treatment
In a placebo-controlled trial, the control group receives an inert substance that looks identical to the active treatment, allowing true comparison of treatment effects.
Question 5: Which study design follows a group of participants over time to assess outcomes?
- Cross-sectional study
- Case-control study
- Cohort study (Correct answer)
- Ecological study
Correct answer: Cohort study
A cohort study follows a defined group of people (a cohort) over time to observe outcomes, making it effective for studying incidence and causality.
Question 6: What is the primary purpose of a Phase III clinical trial?
- First-in-human safety testing
- Dose-finding in healthy volunteers
- Confirming efficacy and monitoring adverse reactions in a large population (Correct answer)
- Post-approval safety surveillance
Correct answer: Confirming efficacy and monitoring adverse reactions in a large population
Phase III trials enroll large patient populations to confirm efficacy, monitor adverse reactions, and compare the new treatment to existing standard therapies prior to regulatory approval.
CTA CTA Biostatistics & Study Design 1
Which type of clinical trial design randomly assigns participants to treatment or control groups to minimize bias?