Identifying Missing IS-A Relations in SNOMED CT with Fine-Tuned Pre-trained Language Models and Non-lattice Subgraphs

Ensuring the completeness of IS-A relations in SNOMED CT is crucial for maintaining its accuracy in clinical applications. In this study, we propose a hybrid approach leveraging non-lattice subgraphs and pre-trained language models (PLMs) to identify missing IS-A relations in SNOMED CT. We fine-tuned four BERT-based models: BERT, DistillBERT, DeBERTa, and BioClinicalBERT, and four generative large language models (LLMs): BioMistral, Llama3, Gemma2, and Phi-4. Missing IS-A relations were identified through consensus predictions by all eight models. De-BERTa achieved the best performance (precision: 0.96, recall: 0.97, F1-score: 0.965) for IS-A relation prediction. Our approach identified 678 potential missing IS-A relations in SNOMED CT (March 2023 US Edition), of which 100 randomly selected cases were manually reviewed by a domain expert, confirming 93 as valid (93% precision). These results demonstrate the effectiveness of fine-tuned PLMs in detecting missing IS-A relations within non-lattice subgraphs, offering a promising avenue for improving SNOMED CT's quality.