Alternative covariance structures in mixed-effects models: Addressing intra- and inter-individual heterogeneity.

ABSTRACT: Mixed-effects models for repeated measures and longitudinal data include random coefficients that are unique to the individual, and thus permit subject-specific growth trajectories, as well as direct study of how the coefficients of a growth function vary as a function of covariates. Although applications of these models often assume homogeneity of the within-subject residual variance that characterizes within-person variation after accounting for systematic change and the variances of the random coefficients of a growth model that quantify individual differences in aspects of change, alternative covariance structures can be considered. These include allowing for serial correlations between the within-subject residuals to account for dependencies in data that remain after fitting a particu

SUBMITTER: Blozis SA 

PROVIDER: S-EPMC11327215 | biostudies-literature | 2024 Mar

REPOSITORIES: biostudies-literature