Early prediction of patient outcomes is important for targeting preventive care. This protocol describes a practical workflow for developing deep-learning risk models that can predict various clinical and operational outcomes from structured electronic health record (EHR) data. The protocol comprises five main stages: formal problem definition, data pre-processing, architecture selection, calibration and uncertainty, and generalizability evaluation. We have applied the workflow to four endpoints (acute kidney injury, mortality, length of stay and 30-day hospital readmission). The workflow can enable continuous (e.g., triggered every 6 h) and static (e.g., triggered at 24 h after admission) predictions. We also provide an open-source codebase that illustrates some key principles in EHR modeling. This protocol can be used by interdisciplinary teams with programming and clinical expertise to build deep-learning prediction models with alternate data sources and prediction tasks.
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The clinical data used for the training, validation and test sets were collected at the VA and transferred to a secure data center with strict access controls in de-identified format. Data were used with both local and national permissions. The dataset is not publicly available, and restrictions apply to its use. The full results from the evaluation of our AKI model can be found in Tomasev et al15.
Code is available at https://github.com/google/ehr-predictions. This example code illustrates the core components of the continuous prediction architecture, task configuration and auxiliary heads. The full data pre-processing pipeline is not included here because it is highly specific to this dataset. However, we do include synthetic examples of the pre-processing stages with an accompanying data-reading notebook. We believe this exemplar code can be appropriately customized to other EHR datasets and tasks.
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We thank the veterans and their families under the care of the VA. We also thank A. Phalen, A. Graves, O. Vinyals, K. Kavukcuoglu, S. Chiappa, T. Lillicrap, R. Raine, P. Keane, A. Schlosberg, O. Ronneberger, J. De Fauw, K. Ruark, M. Jones, J. Quinn, D. Chou, C. Meaden, G. Screen, W. West, R. West, P. Sundberg and the Google Research team, J. Besley, M. Bawn, K. Ayoub and R. Ahmed. Special thanks to K. Peterson and the many other VA staff, including physicians, administrators and researchers who worked on the data collection. Thanks to the many DeepMind and Google Health colleagues for their support, ideas and encouragement. G.R. & H.M. were supported by University College London and the National Institute for Health Research (NIHR) University College London Hospitals Biomedical Research Centre. The views expressed are those of these author(s) and not necessarily those of the NHS, the NIHR or the Department of Health.
G.R., H.M. and C.L. are paid contractors of DeepMind/Google Health.
Peer review information Nature Protocols thanks Issam El Naqa and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.
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Tomašev, N. et al. Nature 572, 116–119 (2019): https://doi.org/10.1038/s41586-019-1390-1
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Tomašev, N., Harris, N., Baur, S. et al. Use of deep learning to develop continuous-risk models for adverse event prediction from electronic health records. Nat Protoc 16, 2765–2787 (2021). https://doi.org/10.1038/s41596-021-00513-5
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