Model misspecification in stepped wedge trials: Random effects for time or treatment.

ABSTRACT: Mixed models are commonly used to analyze stepped wedge trials (SWTs) to account for clustering and repeated measures on clusters. One critical issue researchers face is whether to include a random time effect or a random treatment effect. When the wrong model is chosen, inference on the treatment effect may be invalid. We explore asymptotic and finite-sample convergence of variance component estimates when the model is misspecified and how misspecification affects the estimated variance of the treatment effect. For asymptotic results, we rely on analytical solutions rather than simulation studies, which allow us to succinctly describe the convergence of misspecified estimates, even though there are multiple roots for each misspecified model. We found that both direction and magnitude of t

SUBMITTER: Voldal EC 

PROVIDER: S-EPMC9007853 | biostudies-literature | 2022 May

REPOSITORIES: biostudies-literature