Title: Individualized Risk Prognosis for Critical Care Patients: A Multi-task Gaussian Process Model,
Abstract: We report the development and validation of a data-driven real-time risk
score that provides timely assessments for the clinical acuity of ward patients
based on their temporal lab tests and vital signs, which allows for timely
intensive care unit (ICU) admissions. Unlike the existing risk scoring
technologies, the proposed score is individualized; it uses the electronic
health record (EHR) data to cluster the patients based on their static
covariates into subcohorts of similar patients, and then learns a separate
temporal, non-stationary multi-task Gaussian Process (GP) model that captures
the physiology of every subcohort. Experiments conducted on data from a
heterogeneous cohort of 6,094 patients admitted to the Ronald Reagan UCLA
medical center show that our risk score significantly outperforms the
state-of-the-art risk scoring technologies, such as the Rothman index and MEWS,
in terms of timeliness, true positive rate (TPR), and positive predictive value
(PPV). In particular, the proposed score increases the AUC with 20% and 38% as
compared to Rothman index and MEWS respectively, and can predict ICU admissions
8 hours before clinicians at a PPV of 35% and a TPR of 50%. Moreover, we show
that the proposed risk score allows for better decisions on when to discharge
clinically stable patients from the ward, thereby improving the efficiency of
hospital resource utilization.