Personalized Risk Scoring for Critical Care Prognosis using Mixtures of Gaussian Processes
This work addresses the need for personalized risk scoring in critical care settings, offering potential clinical and social benefits for over 200,000 critically ill inpatients with cardiac arrests annually in the US, but it is incremental as it builds on existing methods like Gaussian Processes and transfer learning.
The paper tackled the problem of providing timely and granular risk assessments for clinical acuity in ward patients using temporal lab tests and vital signs, resulting in a risk scoring algorithm that significantly outperforms existing scores like Rothman index, MEWS, APACHE, and SOFA in terms of timeliness, true positive rate, and positive predictive value on a cohort of 6,321 patients.
Objective: In this paper, we develop a personalized real-time risk scoring algorithm that provides timely and granular assessments for the clinical acuity of ward patients based on their (temporal) lab tests and vital signs; the proposed risk scoring system ensures timely intensive care unit (ICU) admissions for clinically deteriorating patients. Methods: The risk scoring system learns a set of latent patient subtypes from the offline electronic health record data, and trains a mixture of Gaussian Process (GP) experts, where each expert models the physiological data streams associated with a specific patient subtype. Transfer learning techniques are used to learn the relationship between a patient's latent subtype and her static admission information (e.g. age, gender, transfer status, ICD-9 codes, etc). Results: Experiments conducted on data from a heterogeneous cohort of 6,321 patients admitted to Ronald Reagan UCLA medical center show that our risk score significantly and consistently outperforms the currently deployed risk scores, such as the Rothman index, MEWS, APACHE and SOFA scores, in terms of timeliness, true positive rate (TPR), and positive predictive value (PPV). Conclusion: Our results reflect the importance of adopting the concepts of personalized medicine in critical care settings; significant accuracy and timeliness gains can be achieved by accounting for the patients' heterogeneity. Significance: The proposed risk scoring methodology can confer huge clinical and social benefits on more than 200,000 critically ill inpatient who exhibit cardiac arrests in the US every year.