Bias and inference from misspecified mixed-effect models in stepped wedge trial analysis.

ABSTRACT: Many stepped wedge trials (SWTs) are analysed by using a mixed-effect model with a random intercept and fixed effects for the intervention and time periods (referred to here as the standard model). However, it is not known whether this model is robust to misspecification. We simulated SWTs with three groups of clusters and two time periods; one group received the intervention during the first period and two groups in the second period. We simulated period and intervention effects that were either common-to-all or varied-between clusters. Data were analysed with the standard model or with additional random effects for period effect or intervention effect. In a second simulation study, we explored the weight given to within-cluster comparisons by simulating a larger intervention effect in th

SUBMITTER: Thompson JA 

PROVIDER: S-EPMC5600088 | biostudies-literature | 2017 Oct

REPOSITORIES: biostudies-literature