Clinical Trial Design Flashcards
7 cards from real CCDM practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Clinical Trial Design flashcards as text
When calculating sample size for a superiority trial, increasing the desired statistical power from 80% to 90% will generally:
Answer: Increase the required sample size
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.
In a parallel-group randomized controlled trial, the term 'double-blind' means that:
Answer: Neither the participants nor the outcome assessors know the treatment assignments
Double-blind trials conceal treatment assignment from both participants and investigators/outcome assessors to minimize performance and detection bias.
A 'pragmatic' clinical trial differs from an 'explanatory' trial primarily in that it:
Answer: Tests whether an intervention works in routine clinical practice conditions
Pragmatic trials assess effectiveness under real-world clinical conditions with broad inclusion criteria, whereas explanatory trials maximize internal validity under controlled conditions.
Which of the following is an example of a Type I error in a clinical trial?
Answer: Concluding a treatment is effective when it actually has no effect
A Type I error (false positive) occurs when the null hypothesis is incorrectly rejected, leading to the conclusion that an ineffective treatment works.
In a cluster randomized trial, the unit of randomization is:
Answer: A group of individuals, such as a clinic, school, or community
Cluster randomized trials randomize intact groups (clusters) rather than individuals, which is useful when individual randomization would lead to contamination.
Which type of bias is specifically controlled by blinding in a randomized trial?
Answer: Performance bias and detection bias
Blinding controls performance bias (differential treatment of participants by caregivers) and detection bias (differential outcome assessment) by keeping group assignment unknown.
A 'seamless Phase II/III' adaptive design is specifically intended to:
Answer: Combine dose selection or population selection with confirmatory Phase III testing in one trial
Seamless Phase II/III designs combine the learning (dose/population selection) and confirmatory phases into a single trial, potentially saving time and resources.