Adaptation and interim decisions

Specify triggers actions and boundaries

Prespecify information times and authorized actions. Distinguish planned adaptations from unplanned amendments and explain deviations. Interim confidentiality protects ongoing conduct and interpretation.

Flow diagram

Steps

Choose adaptation type

Select stopping, sample-size re-estimation, arm selection or another justified variant.

Define information times and triggers

Specify timing, minimum information and handling of delayed outcomes.

Specify decision boundaries and actions

Record permitted changes, continuation rules and binding/nonbinding status.

Separate review responsibilities

Define who sees unblinded data and who implements decisions.

Record decisions and deviations

Retain the algorithm version, evidence, authority and rationale.

Continue as planned

Maintain the current design when continuation criteria hold.

Apply permitted adaptation

Implement only the protocol-authorized action.

Stop or close comparison

Apply the prespecified stopping rule with review authority.