A SAS procedure based on mixture models for estimating developmental trajectories

摘要: This article introduces a new SAS procedure written by the authors that analyzes longitudinal data (developmental trajectories) fitting mixture model. The TRAJ fits semiparametric (discrete) mixtures of censored normal, Poisson, zero-inflated and Bernoulli distributions to data. Applications psychometric scale data, offense counts, dichotomous prevalence measure in violence research are illustrated. In addition, use Bayesian information criterion address problem model selection, including estimation number components mixture, is demonstrated.