DMS Statistics and Data Science Seminar

Speaker: Dr. JungWun Lee (Assistant Professor, Department of Biostatistics, Boston University School of Public Health)

Title: A latent trajectory analysis for multivariate mixed outcomes: a study on the effect of bariatric surgery via electronic health records.

Abstract: Trajectory analysis can be a statistical solution for explaining heterogeneities by partitioning patients into less heterogeneous subgroups based on similarities in outcome variables. This work proposes a novel trajectory analysis for electronic health records, a longitudinal data set containing multiple biomarkers, demographic factors of patients, and many missing values. The proposed model discovers subgroups of patients so that patients with the same trajectory group memberships are similar in their observed outcomes, while patients with different trajectories are heterogeneous. The proposed model may conceive multivariate mixed outcomes consisting of categorical and continuous variables simultaneously. We suggest an estimation strategy using the expectation-maximization algorithm, which provides the maximum-likelihood estimates and is highly stable to many missing values. We also present an application of our methodology to the DURABLE data set, an NIH-funded study examining long-term outcomes of patients who experienced bariatric surgery between 2007 and 2011.