… Group-Based Trajectory Analysis • Identify subgroups that follow distinct longitudinal
trajectories – Assume population made of distinct, but unobserved, subpopulations with
different behavioral patterns – Use observed data to identify these groups (form of latent
class analysis) … – Patients may have baseline behavioral phenotypes, but longitudinal
events may also be key drivers …

Background Retention in HIV treatment must be improved to advance the HIV response, but
research to characterize gaps in retention has focused on estimates from single time points
and population-level averages. These approaches do not assess the engagement patterns
of individual patients over time and fail to account for both their dynamic nature and the
heterogeneity between patients. We apply group-based trajectory analysis—a special
application of latent class analysis to longitudinal data—among new antiretroviral therapy …