title: Measures of discrimination for latent group-based trajectory models.
abstract: In clinical research, patient care decisions are often easier to make if patients are classified into a manageable number of groups based on homogeneous risk patterns. Investigators can use latent group-based trajectory modeling to estimate the posterior probabilities that an individual will be classified into a particular group of risk patterns. Although this method is increasingly used in clinical research, there is currently no measure that can be used to determine whether an individual's group assignment has a high level of discrimination. In this study, we propose a discrimination index and provide confidence intervals of the probability of the assigned group for each individual. We also propose a modified form of entropy to measure discrimination. The two proposed measures were applied to assess the group assignments of the longitudinal patterns of conduct disorders among young adolescent girls.
authors.affiliation: Division of Gastroenterology, Hepatology, and Nutrition, University of Pittsburgh, Pittsburgh, PA, USA.
authors.forename: Nilesh H
authors.initials: NH
authors.lastname: Shah
authors.affiliation: Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA.
authors.forename: Alison E
authors.initials: AE
authors.lastname: Hipwell
authors.affiliation: Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA.
authors.forename: Stephanie D
authors.initials: SD
authors.lastname: Stepp
authors.affiliation: Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA ; Department of Biostatistics, University of Pittsburgh, Pittsburgh, PA, USA.
authors.forename: Chung-Chou H
authors.initials: CC
authors.lastname: Chang
keywords: Latent class models; discrimination; entropy; longitudinal data; trajectory analysis