Towards cost-effective and trustworthy healthcare machine learning

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Abstract/Contents

Abstract
Machine learning (ML) has made exciting progress across many healthcare tasks, such as chest X-Ray interpretation and seizure detection from electroencephalograms (EEGs). However, while ML models exhibit impressive overall performance, we identify two critical roadblocks to model development and deployment: (1) reliance on massive training datasets created via manual expert labeling, resulting in high annotation costs, and (2) reliance on non-generalizable features, resulting in unexpected poor performance on subgroups of patients ("hidden stratification"). As a result, healthcare ML is currently costly to develop and can be untrustworthy to deploy. To address the first roadblock, we develop new forms of cost-effective supervised training of ML models with cross-modal data programming (XMDP). In particular, healthcare data are often accompanied by other data modalities that contain task-related information for which it is feasible to create labeling functions at low cost, such as clinical reports, workflow notes, or (in the future) gaze data (i.e., eye-tracking data). We develop labeling functions that map the auxiliary data modalities (either text or gaze) to labels using only a small amount of manual labels. Once we develop these labeling functions, we are then able to scale labeled training sets without additional annotation costs. To address the second roadblock, we propose to improve robustness of ML models to hidden stratification by increasing task specificity in two exemplar medical tasks, pneumothorax detection in medical imaging and seizure detection in electroencephalogram (EEG) time series data. For medical imaging, as opposed to training a binary classification model for detecting pneumothorax (low task specificity), we first train an image segmentation model to localize pneumothorax (higher task specificity) and use the segmentation output to derive the binary prediction. For detection of seizure on EEG, we increase task specificity by training a model to classify additional attributes in the EEG, such as artifacts. We find that increasing task specificity significantly reduces reliance on non-generalizable features and improves performance among clinically meaningful subgroups, which decreases performance gaps among subgroups and results in more trustworthy models. In summary, our work investigated new forms of model supervision that are less costly than existing approaches, and uncovered strong connections between task specificity and model robustness. While our experiments focus on chest X-ray classification and EEG seizure detection, our proposed methods are applicable to a wider range of healthcare applications.

Description

Type of resource text
Form electronic resource; remote; computer; online resource
Extent 1 online resource.
Place California
Place [Stanford, California]
Publisher [Stanford University]
Copyright date 2023; ©2023
Publication date 2023; 2023
Issuance monographic
Language English

Creators/Contributors

Author Saab, Khaled Kamal
Degree supervisor Re, Chris
Degree supervisor Rubin, Daniel
Thesis advisor Re, Chris
Thesis advisor Rubin, Daniel
Thesis advisor Lee-Messer, Christopher
Thesis advisor Pauly, John
Thesis advisor Pilanci, Mert
Degree committee member Lee-Messer, Christopher
Degree committee member Pauly, John
Degree committee member Pilanci, Mert
Associated with Stanford University, School of Engineering
Associated with Stanford University, Department of Electrical Engineering

Subjects

Genre Theses
Genre Text

Bibliographic information

Statement of responsibility Khaled K. Saab.
Note Submitted to the Department of Electrical Engineering.
Thesis Thesis Ph.D. Stanford University 2023.
Location https://purl.stanford.edu/wr751rz0386

Access conditions

Copyright
© 2023 by Khaled Kamal Saab
License
This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).

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