Question

Which type of "blinding" is most commonly utilized in Randomized Controlled Trials (RCTs) to reduce bias?

• A. Single-blind
• B. Double-blind
• C. Triple-blind
• D. Open-label

Hint:

Double-blind = \textbf{Participant + Investigator unaware} $\Rightarrow$ Best balance of practicality and bias control.

Answer 1

The Correct Option is B

Concept: Blinding (masking) in clinical trials is used to reduce bias by preventing participants and/or investigators from knowing which intervention is being administered.

• Single-blind: Only the participant is unaware.
• Double-blind: Both participant and investigator are unaware.
• Triple-blind: Participant, investigator, and data analyst are unaware.
• Open-label: No blinding.

Step 1: Understand purpose of blinding.
Blinding minimizes bias in outcome assessment, placebo effect, and treatment administration.
Step 2: Identify the most commonly used type.
Double-blind trials are most widely used because they effectively reduce both participant and observer bias.
Step 3: Compare with other types.

• Single-blind reduces only participant bias.
• Triple-blind is more rigorous but less commonly used.
• Open-label has no bias control.

Step 4: Conclude the answer.
Thus, the most commonly utilized blinding method in RCTs is double-blind.