  Electronic Health Records (EHRs) aggregate diverse information at the patient
level, holding a trajectory representative of the evolution of the patient
health status throughout time. Although this information provides context and
can be leveraged by physicians to monitor patient health and make more accurate
prognoses/diagnoses, patient records can contain information from very long
time spans, which combined with the rapid generation rate of medical data makes
clinical decision making more complex. Patient trajectory modelling can assist
by exploring existing information in a scalable manner, and can contribute in
augmenting health care quality by fostering preventive medicine practices. We
propose a solution to model patient trajectories that combines different types
of information and considers the temporal aspect of clinical data. This
solution leverages two different architectures: one supporting flexible sets of
input features, to convert patient admissions into dense representations; and a
second exploring extracted admission representations in a recurrent-based
architecture, where patient trajectories are processed in sub-sequences using a
sliding window mechanism. The developed solution was evaluated on two different
clinical outcomes, unexpected patient readmission and disease progression,
using the publicly available MIMIC-III clinical database. The results obtained
demonstrate the potential of the first architecture to model readmission and
diagnoses prediction using single patient admissions. While information from
clinical text did not show the discriminative power observed in other existing
works, this may be explained by the need to fine-tune the clinicalBERT model.
Finally, we demonstrate the potential of the sequence-based architecture using
a sliding window mechanism to represent the input data, attaining comparable
performances to other existing solutions.
