Where are the analysis sets typically defined in a clinical trial protocol?

• A. Outline data collection schedules.
• B. Define the analysis sets in the statistical section of the protocol.
• C. Describe the trial population demographics.
• D. Specify the randomization algorithm.

Answer: (B)

Defining how data will be analyzed, including which participants are included in each analysis, is specified in the protocol’s statistical section. The analysis sets describe the populations used for primary and secondary analyses (for example, full analysis set, per-protocol, and safety set) and outline how deviations and missing data are handled. This placement keeps the plan focused on how results will be derived rather than on how data are collected, who was enrolled, or how participants were randomized. Data collection schedules concern when data are gathered, trial demographics describe who was enrolled, and the randomization algorithm explains allocation—not the analysis populations. For clarity, the statistical section is where you’d find the definitions and rules for which participants count in each analysis, with concrete examples such as a full analysis set including all randomized participants who received at least one dose and have post-baseline data, and a per-protocol set excluding major deviations.