Utilisation of the signature method to identify the early onset of sepsis from multivariate physiological time series in critical care monitoring

Objectives:
Patients in an ICU are particularly vulnerable to sepsis. It is therefore important to detect its onset as early as possible. This study focuses on the development and validation of a new signature-based regression model, augmented with a particular choice of the handcrafted features, to identify a patient’s risk of sepsis based on physiologic data streams. The model makes a positive or negative prediction of sepsis for every time interval since admission to the ICU.

Design:
The data were sourced from the PhysioNet/Computing in Cardiology Challenge 2019 on the “Early Prediction of Sepsis from Clinical Data.” It consisted of ICU patient data from three separate hospital systems. Algorithms were scored against a specially designed utility function that rewards early predictions in the most clinically relevant region around sepsis onset and penalizes late predictions and false positives.

Setting:
The work was completed as part of the PhysioNet 2019 Challenge alongside 104 other teams.

Patients:
PhysioNet sourced over 60,000 ICU patients with up to 40 clinical variables for each hour of a patient’s ICU stay. The Sepsis-3 criteria was used to define the onset of sepsis.

Interventions:
None.

Measurements and Main Results:
The algorithm yielded a utility function score which was the first placed entry in the official phase of the challenge.