CLARUS: Hierarchical Hypergraph Modeling for Unsupervised Discharge Summarization

Gaetano Cimino, Mir Rayat Imtiaz Hossain, Laura De Santis, Amirhossein Abaskohi, Raymond T. Ng, Giuseppe Carenini, Vincenzo Deufemia


Abstract
Discharge summary generation from clinical records is challenging due to long, heterogeneous inputs and the need to preserve clinically relevant information. Although Large Language Models (LLMs) have improved abstractive summarization, their direct application to full patient records is limited by context length and difficulties in aggregating evidence across notes. We present CLARUS, a fully unsupervised framework that models patient records as hypergraphs encoding multi-dimensional relations. A hierarchical hypergraph encoder with depth-aware concept attention strengthens sparse representations, while a variational information bottleneck with Gumbel-Softmax relaxation enables differentiable selection of compact, informative subsets for LLM generation. Experiments on MIMIC-III show that CLARUS outperforms strong unsupervised baselines across lexical, semantic, and clinical metrics, demonstrating the value of higher-order structure and concept hierarchy for faithful multi-document clinical summarization.
Anthology ID:
2026.emnlp-main.2067
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
EMNLP
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SIGDAT
Publisher:
Association for Computational Linguistics
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Pages:
47070–47091
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URL:
https://aclanthology.org/2026.emnlp-main.2067/
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Cite (ACL):
Gaetano Cimino, Mir Rayat Imtiaz Hossain, Laura De Santis, Amirhossein Abaskohi, Raymond T. Ng, Giuseppe Carenini, and Vincenzo Deufemia. 2026. CLARUS: Hierarchical Hypergraph Modeling for Unsupervised Discharge Summarization. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 47070–47091, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
CLARUS: Hierarchical Hypergraph Modeling for Unsupervised Discharge Summarization (Cimino et al., EMNLP 2026)
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https://aclanthology.org/2026.emnlp-main.2067.pdf