Crossover analysis specification

Specify period sequence and sensitivity

Prespecify treatment and period effects and a suitable repeated-measure covariance structure. Avoid selecting a first-period-only analysis on the basis of a preliminary carryover test. Investigate plausible carryover through design and sensitivity analyses.

Flow diagram

Steps

Specify treatment-effect model

Choose a paired or repeated-measure method appropriate to the outcome.

Account for period and sequence

State model terms and assumptions without treating periods as independent.

Address carryover concerns

Prespecify design-based carryover reasoning and sensitivity. Do not select a first-period-only analysis using a preliminary carryover significance test.

Handle missing periods

Define assumptions and methods for incomplete sequences.

Report contrasts and uncertainty

Report the prespecified within-participant contrasts and uncertainty, period and sequence terms, missing periods and sensitivity results.