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Currently submitted to: JMIR Medical Informatics

Date Submitted: Jan 15, 2020
Open Peer Review Period: Jan 14, 2020 - Feb 17, 2020
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Use of Clinical Notes and Machine Learning to Predict Onset of Dementia

  • Christopher A Hane; 
  • Vijay S Nori; 
  • William H Crown; 
  • Darshak M Sanghavi; 
  • Paul Bleicher; 



Clinical trials need efficient tools to assist in recruiting patients at risk of Alzheimer’s Disease and related dementia (ADRD). Early detection can also assist patients with financial planning for long-term care. Clinical notes are an important under-utilized source of information in machine learning models due to the cost of collection and complexity of analysis.


This study investigates using de-identified clinical notes from multiple hospital systems collected over 10 years to augment retrospective machine learning models of ADRD risk.


The models use two years of data to predict a future outcome of ADRD onset. Notes data are provided in a de-identified format with specific terms and sentiments. Terms in notes are embedded into a 100-dimensional vector space to identify clusters of related terms and abbreviations that differ across hospital systems and individual clinicians.


When using notes, AUC improved from 85% to 94% and positive predictive value (PPV) increased from 45% to 68% in the model at disease onset. Models with notes improved in both AUC and PPV in years 3-6 when notes volume was largest, results are mixed in years 7 and 8 with smallest cohorts.


While notes helped in the short term, the presence of ADRD symptomatic terms years earlier than onset adds evidence to other studies that clinicians under-code ADRD diagnoses. De-identified clinical notes increase the accuracy of risk models. Clinical notes collected across multiple hospital systems via natural language processing can be merged using post-processing techniques to aid model accuracy.


Please cite as:

Hane CA, Nori VS, Crown WH, Sanghavi DM, Bleicher P

Use of Clinical Notes and Machine Learning to Predict Onset of Dementia

JMIR Preprints. 15/01/2020:17819

DOI: 10.2196/preprints.17819


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