Study Design & Methodology Flashcards

Which of the following is an example of an adaptive trial design?

Answer: Pre-specified sample size reestimation at interim

Adaptive designs allow pre-specified modifications (such as sample size reestimation) based on interim data while maintaining trial integrity.

In a crossover trial, the 'washout period' serves to:

Answer: Eliminate carryover effects from prior treatment

The washout period allows prior treatment effects to dissipate before participants receive the next treatment, preventing carryover bias.

A researcher compares outcomes between patients who chose drug A versus drug B without randomization. The main methodological threat is:

Answer: Confounding by indication

Confounding by indication occurs when the reason for choosing a treatment (indication) is also related to the outcome, distorting effect estimates.

The CONSORT statement was developed primarily to improve reporting of:

Answer: Randomized controlled trials

CONSORT (Consolidated Standards of Reporting Trials) provides a checklist and flow diagram to improve transparency in RCT reporting.

Which bias can occur when study participants who drop out differ systematically from those who complete the study?

Answer: Attrition bias

Attrition bias (loss-to-follow-up bias) occurs when dropouts differ from completers in ways that affect the outcome, distorting results.

A Phase I clinical trial primarily aims to:

Answer: Determine maximum tolerated dose and safety profile

Phase I trials focus on safety, pharmacokinetics, and determining the maximum tolerated dose, typically in a small number of participants.

Which of the following best describes a 'pragmatic' clinical trial?

Answer: Real-world conditions testing whether a treatment works in practice

Pragmatic trials test interventions under real-world clinical conditions with broad eligibility to assess effectiveness in routine practice.