Time-varying outcomes in group-based trajectory modeling

Music City Center 

We discuss an application of group-based trajectory modeling where the inference target is the effect of trajectory shape on an outcome variable that is measured at irregular timepoints and possibly more than once per subject. Unlike many applications of group-based trajectory modeling, where measurements of both the trajectory variable and the outcome are taken at the same time points or ages across subjects, our setting requires careful consideration of the temporal dependencies among the variables. We describe techniques for accounting for such dependencies and illustrate them in an application involving longitudinal blood pressure measurements and a neuroimaging outcome.