Multi-task Heterogeneous Graph Learning on Electronic Health Records

TL;DR

This paper introduces MulT-EHR, a multi-task heterogeneous graph learning framework for electronic health records that improves prediction accuracy across multiple clinical tasks by modeling complex relations and reducing noise.

Contribution

The paper presents a novel multi-task graph neural network framework with a denoising module based on causal inference for EHR analysis, addressing heterogeneity and noise issues.

Findings

Outperforms state-of-the-art methods on MIMIC datasets

Effective in drug recommendation, length of stay, mortality, and readmission prediction

Demonstrates robustness through ablation studies

Abstract

Learning electronic health records (EHRs) has received emerging attention because of its capability to facilitate accurate medical diagnosis. Since the EHRs contain enriched information specifying complex interactions between entities, modeling EHRs with graphs is shown to be effective in practice. The EHRs, however, present a great degree of heterogeneity, sparsity, and complexity, which hamper the performance of most of the models applied to them. Moreover, existing approaches modeling EHRs often focus on learning the representations for a single task, overlooking the multi-task nature of EHR analysis problems and resulting in limited generalizability across different tasks. In view of these limitations, we propose a novel framework for EHR modeling, namely MulT-EHR (Multi-Task EHR), which leverages a heterogeneous graph to mine the complex relations and model the heterogeneity in the EHRs. To mitigate the large degree of noise, we introduce a denoising module based on the causal inference framework to adjust for severe confounding effects and reduce noise in the EHR data. Additionally, since our model adopts a single graph neural network for simultaneous multi-task prediction, we design a multi-task learning module to leverage the inter-task knowledge to regularize the training process. Extensive empirical studies on MIMIC-III and MIMIC-IV datasets validate that the proposed method consistently outperforms the state-of-the-art designs in four popular EHR analysis tasks -- drug recommendation, and predictions of the length of stay, mortality, and readmission. Thorough ablation studies demonstrate the robustness of our method upon variations to key components and hyperparameters.