CHiLL: Zero-shot Custom Interpretable Feature Extraction from Clinical Notes with Large Language Models

Denis McInerney, Geoffrey Young, Jan-Willem van de Meent, Byron Wallace


Abstract
We propose CHiLL (Crafting High-Level Latents), an approach for natural-language specification of features for linear models. CHiLL prompts LLMs with expert-crafted queries to generate interpretable features from health records. The resulting noisy labels are then used to train a simple linear classifier. Generating features based on queries to an LLM can empower physicians to use their domain expertise to craft features that are clinically meaningful for a downstream task of interest, without having to manually extract these from raw EHR. We are motivated by a real-world risk prediction task, but as a reproducible proxy, we use MIMIC-III and MIMIC-CXR data and standard predictive tasks (e.g., 30-day readmission) to evaluate this approach. We find that linear models using automatically extracted features are comparably performant to models using reference features, and provide greater interpretability than linear models using “Bag-of-Words” features. We verify that learned feature weights align well with clinical expectations.
Anthology ID:
2023.findings-emnlp.568
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2023
Month:
December
Year:
2023
Address:
Singapore
Editors:
Houda Bouamor, Juan Pino, Kalika Bali
Venue:
Findings
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
8477–8494
Language:
URL:
https://aclanthology.org/2023.findings-emnlp.568
DOI:
10.18653/v1/2023.findings-emnlp.568
Bibkey:
Cite (ACL):
Denis McInerney, Geoffrey Young, Jan-Willem van de Meent, and Byron Wallace. 2023. CHiLL: Zero-shot Custom Interpretable Feature Extraction from Clinical Notes with Large Language Models. In Findings of the Association for Computational Linguistics: EMNLP 2023, pages 8477–8494, Singapore. Association for Computational Linguistics.
Cite (Informal):
CHiLL: Zero-shot Custom Interpretable Feature Extraction from Clinical Notes with Large Language Models (McInerney et al., Findings 2023)
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PDF:
https://aclanthology.org/2023.findings-emnlp.568.pdf