Crossover treatment periods and washout

Specify period timing and carryover

Period length and washout depend on the intervention and disease, not a universal interval. Address residual treatment effects and changes in the underlying condition before choosing crossover.

Flow diagram

Crossover treatment periods and washoutF1.S1Define treatment periodsF1.S2Justify washoutF1.S3Plan transition proceduresF1.S4Specify carryover assumptionsF1.S5Plan period-specific safetyF1.N1Period schedulePeriodTreatment bysequenceDurationWashoutAssessmentInitial periodWashoutSubsequentperiodF1.N2Assumptions and rationaleF1.N3Method and protocol evidenceF1.S0 Start flowCrossover treatment periods andwashoutF1.S999 End flowEnd flow

Steps

Define treatment periods

Specify treatment administration, duration and assessment timing.

Justify washout

Use pharmacological or clinical evidence about persistence and reversibility.

Plan transition procedures

Record washout adherence, re-baseline assessments and permitted delays.

Specify carryover assumptions

Describe residual treatment effects and implications for interpretation.

Plan period-specific safety

Record adverse events, withdrawal and rules for subsequent periods.

Crossover treatment periods and washout

End flow

Tables and supporting information

Period schedule

Period schedulePeriodTreatment bysequenceDurationWashoutAssessmentInitial periodWashoutSubsequentperiod

Expand rows to match the prespecified number of periods.

Assumptions and rationale

A washout label does not establish absence of carryover; justify duration and suitable design assumptions.

Method and protocol evidence

Attach the protocol, methodological sources and versioned software specification supporting these decisions. Record citations and provenance; do not enter participant identifiers.

Sources