Randomized controlled trials usually have more bias than non-randomized controlled trials.

Randomized controlled trials usually have more bias than non-randomized controlled trials.

• A. Sometimes
• B. True
• C. Not applicable
• D. False

Answer: (D)

Randomization helps balance both known and unknown prognostic factors between groups, reducing confounding. Allocation concealment prevents selection bias by ensuring assignments aren’t predictable, and blinding minimizes performance and assessment biases. Non-randomized trials lack these protections, so they’re more prone to biases such as confounding by indication and selection bias. While no study is completely free of bias, randomized controlled trials are generally less biased than non-randomized designs, which is why they’re considered the preferred approach for assessing causal effects.

Randomization helps balance both known and unknown prognostic factors between groups, reducing confounding. Allocation concealment prevents selection bias by ensuring assignments aren’t predictable, and blinding minimizes performance and assessment biases. Non-randomized trials lack these protections, so they’re more prone to biases such as confounding by indication and selection bias. While no study is completely free of bias, randomized controlled trials are generally less biased than non-randomized designs, which is why they’re considered the preferred approach for assessing causal effects.