BiT-MAC: Mortality prediction by bidirectional time and multi-feature attention coupled network on multivariate irregular time series. (March 2023)

• Record Type: Journal Article
• Authors: Wang, Qinfen; Chen, Geng; Jin, Xuting; Ren, Siyuan; Wang, Gang; Cao, Longbing; Xia, Yong
• Is Part Of: Computers in biology and medicine. Volume 155(2023)
• Publication Date: 2023-03
• Subjects: Mortality prediction -- Irregular multivariate time series -- Multivariate learning -- Multi-head attention; Medicine -- Data processing -- Periodicals; Biology -- Data processing -- Periodicals; 610.285
• DOI: 10.1016/j.compbiomed.2023.106586
• Languages: English
• ISSNs: 0010-4825

Abstract

Abstract: Mortality prediction is crucial to evaluate the severity of illness and assist in improving the prognosis of patients. In clinical settings, one way is to analyze the multivariate time series (MTSs) of patients based on their medical data, such as heart rates and invasive mean arterial blood pressure. However, this suffers from sparse, irregularly sampled, and incomplete data issues. These issues can compromise the performance of follow-up MTS-based analytic applications. Plenty of existing methods try to deal with such irregular MTSs with missing values by capturing the temporal dependencies within a time series, yet in-depth research on modeling inter-MTS couplings remains rare and lacks model interpretability. To this end, we propose a bidirectional time and multi-feature attention coupled network (BiT-MAC) to capture the temporal dependencies (i.e., intra-time series coupling) and the hidden relationships among variables (i.e., inter-time series coupling) with a bidirectional recurrent neural network and multi-head attention, respectively. The resulting intra- and inter-time series coupling representations are then fused to estimate the missing values for a more robust MTS-based prediction. We evaluate BiT-MAC by applying it to the missing-data corrupted mortality prediction on two real-world clinical datasets, i.e., PhysioNet'2012 and COVID-19. Extensive experiments demonstrate the superiority of BiT-MAC over cutting-edge models, verifying the great value of the deep and hidden relations captured by MTSs. The interpretability of features is further demonstrated through a case study. Graphical abstract: Highlights: Propose a deep learning model, BiT-MAC, for clinical data-based mortality prediction. Explore intra- and inter-time series couplings for missing value imputation. Provide the interpretability of the coupling relationships between features. Setting new SOTA on the PhysioNet'2012 dataset and COVID-19 dataset.