Bridging Electronic Health Records and Clinical Texts: Contrastive Learning for Enhanced Clinical Tasks
Sara Ketabi, Dhanesh Ramachandram
TL;DR
The paper addresses the bottleneck of limited semantic information in structured EHR data for complex clinical tasks. It proposes a deep multimodal contrastive learning framework that aligns static-form EHR features with discharge summaries using a TabNet encoder for EHR and Longformer for text, trained with a CLIP-style objective, followed by downstream fine-tuning on two high-impact prediction tasks. The approach yields notable improvements in AUROC over strong baselines, with particularly large gains under data-scarce conditions, and demonstrates that CL-based pretraining can serve as a robust initialization for tabular clinical analyses even when text is not required at inference. The framework is modular and adaptable to additional modalities, offering a practical path to richer, context-aware clinical decision support systems in real-world hospital settings.
Abstract
Conventional machine learning models, particularly tree-based approaches, have demonstrated promising performance across various clinical prediction tasks using electronic health record (EHR) data. Despite their strengths, these models struggle with tasks that require deeper contextual understanding, such as predicting 30-day hospital readmission. This can be primarily due to the limited semantic information available in structured EHR data. To address this limitation, we propose a deep multimodal contrastive learning (CL) framework that aligns the latent representations of structured EHR data with unstructured discharge summary notes. It works by pulling together paired EHR and text embeddings while pushing apart unpaired ones. Fine-tuning the pretrained EHR encoder extracted from this framework significantly boosts downstream task performance, e.g., a 4.1% AUROC enhancement over XGBoost for 30-day readmission prediction. Such results demonstrate the effect of integrating domain knowledge from clinical notes into EHR-based pipelines, enabling more accurate and context-aware clinical decision support systems.
