Mixed effects approach to the analysis of the stepped wedge cluster randomised trial-Investigating the confounding effect of time through simulation.

ABSTRACT: BACKGROUND:A stepped wedge cluster randomised trial (SWCRT) is a multicentred study which allows an intervention to be rolled out at sites in a random order. Once the intervention is initiated at a site, all participants within that site remain exposed to the intervention for the remainder of the study. The time since the start of the study ("calendar time") may affect outcome measures through underlying time trends or periodicity. The time since the intervention was introduced to a site ("exposure time") may also affect outcomes cumulatively for successful interventions, possibly in addition to a step change when the intervention began. METHODS:Motivated by a SWCRT of self-monitoring for bipolar disorder, we conducted a simulation study to compare model formulations to analyse data from a

SUBMITTER: Nickless A 

PROVIDER: S-EPMC6292598 | biostudies-literature | 2018

REPOSITORIES: biostudies-literature