posted on 2025-08-01, 00:00authored byRochana Chaturvedi
Timely and accurate prediction of chronic disease risk, such as Type 2 Diabetes, requires models that can reason over complex, longitudinal clinical narratives. This thesis presents a unified framework for temporally grounded patient modeling that integrates structured event representations, fine-grained temporal reasoning, and scalable predictive architectures.
Initial experiments show that concept-based models paired with visit-level temporal modeling outperform traditional baselines that ignore temporal dynamics, motivating a deeper exploration into concept and temporal relation extraction from clinical narratives. Towards this, I introduce GraphTREx, a state-of-the-art temporal relation extraction approach that achieves a 5% F1 improvement on the end-to-end temporal relation extraction task in the I2B2 2012 challenge with ~9% gains on long-distance relations. GraphTREx generalizes well, showing strong performance on the E3C corpus and robust out-of-domain results (without additional adaptation) on a newly annotated UI Health dataset with dense temporal relations, highlighting its portability.
Building on these temporal graphs, I develop HiTGNN—a Hierarchical Temporal Graph Neural Network that integrates intra-document temporal relations, inter-visit dynamics, and external medical knowledge, enabling reasoning across both local event structures and longitudinal patient trajectories. I also introduce ReVeAL (Reasoning with Verifier Aided Labeling), an inference-time scaling framework where a smaller LLM validates predictions from a larger frozen LLM, inheriting interpretability and improving accuracy without full retraining. While our LLM-based approach offers explanations, HiTGNN outperforms it (and other LLM baselines) in accuracy and efficiency, especially over shorter prediction horizons, demonstrating the strength of lightweight, temporally grounded graph-based models, well-suited for low-resource, privacy-sensitive clinical settings.
Rigorous dataset curation, ablations, and analyses reinforce robustness of these approaches. Together, these contributions establish a generalizable framework for clinical prediction by integrating concept abstraction, temporal structure, and semantic enrichment to support robust, privacy-conscious AI systems for real-world clinical decision support.
History
Language
en
Advisor
Barbara Di Eugenio
Department
Computer Science
Degree Grantor
University of Illinois Chicago
Degree Level
Doctoral
Degree name
PhD, Doctor of Philosophy
Committee Member
Elena Zheleva
Sourav Medya
Natalie Parde
Brian Layden