Clustering of Longitudinal Data: A Tutorial on a Variety of Approaches

ABSTRACT During the past two decades, methods for identifying groups with different trends in longitudinal data involving a single numeric outcome have become of increasing interest across many areas of research. To support researchers, we summarize the guidance from literature regarding the clustering of such data. Moreover, we present a selection of methods that take different approaches to clustering longitudinal data, based on cross‐sectional clustering, distance‐based clustering, feature‐based clustering, and mixture modeling. The methods are introduced at a basic level, and strengths, limitations, and model extensions are listed. Following the recent developments in data collection, attention is given to the applicability of these methods to intensive longitudinal data (ILD). We demonstrate the application of the methods on a synthetic dataset using packages available in R.