Power Calculation for Noninferiority Stepped-Wedge Cluster Randomized Trials

Simulation-based framework swNIsim enables accurate power calculation for noninferiority stepped-wedge cluster randomized trials, accommodating diverse design features and outcome types.

• Why it matters: Effective planning of noninferiority SW-CRTs is limited by existing methods, risking underpowered studies or inefficient designs, which hampers reliable evaluation of interventions.
• What they did: The authors developed swNIsim, an R package that uses generalized linear mixed-effects models to simulate and assess power across various trial configurations, including unequal clusters and delayed effects.
• The result: Extensive simulations showed that increasing time periods improves power, while higher between-cluster variability reduces it; balanced cluster allocation enhances efficiency, supporting better trial design decisions.