An efficient representation of chronological events in medical texts

Andrey Kormilitzin, Nemanja Vaci, Qiang Liu, Hao Ni, Goran Nenadic, Alejo Nevado-Holgado


Abstract
In this work we addressed the problem of capturing sequential information contained in longitudinal electronic health records (EHRs). Clinical notes, which is a particular type of EHR data, are a rich source of information and practitioners often develop clever solutions how to maximise the sequential information contained in free-texts. We proposed a systematic methodology for learning from chronological events available in clinical notes. The proposed methodological path signature framework creates a non-parametric hierarchical representation of sequential events of any type and can be used as features for downstream statistical learning tasks. The methodology was developed and externally validated using the largest in the UK secondary care mental health EHR data on a specific task of predicting survival risk of patients diagnosed with Alzheimer’s disease. The signature-based model was compared to a common survival random forest model. Our results showed a 15.4% increase of risk prediction AUC at the time point of 20 months after the first admission to a specialist memory clinic and the signature method outperformed the baseline mixed-effects model by 13.2 %.
Anthology ID:
2020.louhi-1.11
Volume:
Proceedings of the 11th International Workshop on Health Text Mining and Information Analysis
Month:
November
Year:
2020
Address:
Online
Editors:
Eben Holderness, Antonio Jimeno Yepes, Alberto Lavelli, Anne-Lyse Minard, James Pustejovsky, Fabio Rinaldi
Venue:
Louhi
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
97–103
Language:
URL:
https://aclanthology.org/2020.louhi-1.11
DOI:
10.18653/v1/2020.louhi-1.11
Bibkey:
Cite (ACL):
Andrey Kormilitzin, Nemanja Vaci, Qiang Liu, Hao Ni, Goran Nenadic, and Alejo Nevado-Holgado. 2020. An efficient representation of chronological events in medical texts. In Proceedings of the 11th International Workshop on Health Text Mining and Information Analysis, pages 97–103, Online. Association for Computational Linguistics.
Cite (Informal):
An efficient representation of chronological events in medical texts (Kormilitzin et al., Louhi 2020)
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PDF:
https://aclanthology.org/2020.louhi-1.11.pdf
Video:
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