Adaptive trial overview — Adaptive randomized trial

Question

Define the scientific question and why a planned adaptation could improve the design.

Specify adaptation and estimands

Specify estimands, adaptation types, information times and allowable actions before examining interim effects.

Simulate design

Simulate the complete design under null, alternative and operational scenarios; assess error, power, bias, coverage and simulation precision.

Protocol and registration

Freeze the reviewed design and analysis, obtain approvals and register prospectively.

Randomize

Randomize according to the active prespecified allocation rule and retain epoch-specific assignments.

Review interim information

Allow only authorized reviewers access to the defined interim information and quality checks.

Adapt or continue

Document the permitted adaptation, continuation or stopping decision and any departures from the plan.

Final analysis

Use inference compatible with the adaptations, selection and stopping actually implemented.

Report

Report planned and implemented adaptations, operating characteristics, interim governance and final results.

Adaptive trial overview

End flow

Protocol and decision register

Record the protocol, approvals and registration where applicable. Preserve planned decisions and amendments separately from results.

Protocol and rationale evidence

Attach the dated protocol, approvals and amendments. A clinical trial registry publicly records the trial plan, such as ClinicalTrials.gov or an eligible WHO primary registry such as ISRCTN. Record the registry name, identifier and registration date before first enrollment. WHO ICTRP is a search platform, not itself a registry. Registration does not imply randomization.