DKEC: Domain Knowledge Enhanced Multi-Label Classification for Electronic Health Records

Multi-label text classification (MLTC) tasks in the medical domain often face long-tail label distribution, where rare classes have fewer training samples than frequent classes. Although previous works have explored different model architectures and hierarchical label structures to find important features, most of them neglect to incorporate the domain knowledge from medical guidelines. In this paper, we present DKEC, Domain Knowledge Enhanced Classifier for medical diagnosis prediction with two innovations: (1) a label-wise attention mechanism that incorporates a heterogeneous graph and domain ontologies to capture the semantic relationships between medical entities, (2) a simple yet effective group-wise training method based on similarity of labels to increase samples of rare classes. We evaluate DKEC on two real-world medical datasets: the RAA dataset, a collection of 4,417 patient care reports from emergency medical services (EMS) incidents, and a subset of 53,898 reports from the MIMIC-III dataset. Experimental results show that our method outperforms the state-of-the-art, particularly for the few-shot (tail) classes. More importantly, we study the applicability of DKEC to different language models and show that DKEC can help the smaller language models achieve comparable performance to large language models.