CCDM Clinical Trial Design 4

Question 1

When calculating sample size for a superiority trial, increasing the desired statistical power from 80% to 90% will generally:

Accepted Answer

Increase the required sample size

Answer

Higher power means a lower probability of a Type II error (missing a true effect), which requires more participants to detect the same effect size.

Question 2

In a parallel-group randomized controlled trial, the term 'double-blind' means that:

Accepted Answer

Neither the participants nor the outcome assessors know the treatment assignments

Answer

Double-blind trials conceal treatment assignment from both participants and investigators/outcome assessors to minimize performance and detection bias.

Question 3

A 'pragmatic' clinical trial differs from an 'explanatory' trial primarily in that it:

Accepted Answer

Tests whether an intervention works in routine clinical practice conditions

Answer

Pragmatic trials assess effectiveness under real-world clinical conditions with broad inclusion criteria, whereas explanatory trials maximize internal validity under controlled conditions.

Question 4

Which of the following is an example of a Type I error in a clinical trial?

Accepted Answer

Concluding a treatment is effective when it actually has no effect

Answer

A Type I error (false positive) occurs when the null hypothesis is incorrectly rejected, leading to the conclusion that an ineffective treatment works.

Question 5

In a cluster randomized trial, the unit of randomization is:

Accepted Answer

A group of individuals, such as a clinic, school, or community

Answer

Cluster randomized trials randomize intact groups (clusters) rather than individuals, which is useful when individual randomization would lead to contamination.

(CCDM) Certified Clinical Data Manager Practice Test

(CCDM) Certified Clinical Data Manager Practice Test

CCDM Clinical Trial Design 4