<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE article PUBLIC "-//NLM//DTD Journal Publishing DTD v2.0 20040830//EN" "journalpublishing.dtd"><article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" dtd-version="2.0" xml:lang="en" article-type="letter"><front><journal-meta><journal-id journal-id-type="nlm-ta">JMIR AI</journal-id><journal-id journal-id-type="publisher-id">ai</journal-id><journal-id journal-id-type="index">41</journal-id><journal-title>JMIR AI</journal-title><abbrev-journal-title>JMIR AI</abbrev-journal-title><issn pub-type="epub">2817-1705</issn><publisher><publisher-name>JMIR Publications</publisher-name><publisher-loc>Toronto, Canada</publisher-loc></publisher></journal-meta><article-meta><article-id pub-id-type="publisher-id">v4i1e67321</article-id><article-id pub-id-type="doi">10.2196/67321</article-id><article-categories><subj-group subj-group-type="heading"><subject>Letter to the Editor</subject></subj-group></article-categories><title-group><article-title>Predicting the Emergency Department Patient Journey Using a Machine Learning Approach</article-title></title-group><contrib-group><contrib contrib-type="author" corresp="yes"><name name-style="western"><surname>Kovoor</surname><given-names>Joshua George</given-names></name><degrees>MBBS</degrees><xref ref-type="aff" rid="aff1">1</xref><xref ref-type="aff" rid="aff2">2</xref></contrib><contrib contrib-type="author"><name name-style="western"><surname>Carmichael</surname><given-names>Gavin John</given-names></name><degrees>MD</degrees><xref ref-type="aff" rid="aff1">1</xref></contrib><contrib contrib-type="author"><name name-style="western"><surname>Stretton</surname><given-names>Brandon</given-names></name><degrees>MBBS</degrees><xref ref-type="aff" rid="aff3">3</xref></contrib><contrib contrib-type="author"><name name-style="western"><surname>Gupta</surname><given-names>Aashray K</given-names></name><degrees>MBBS</degrees><xref ref-type="aff" rid="aff3">3</xref></contrib><contrib contrib-type="author"><name name-style="western"><surname>Kleinig</surname><given-names>Oliver S</given-names></name><xref ref-type="aff" rid="aff3">3</xref></contrib><contrib contrib-type="author"><name name-style="western"><surname>Ittimani</surname><given-names>Mana</given-names></name><xref ref-type="aff" rid="aff4">4</xref></contrib><contrib contrib-type="author"><name name-style="western"><surname>Fabian</surname><given-names>Jack</given-names></name><xref ref-type="aff" rid="aff5">5</xref></contrib><contrib contrib-type="author"><name name-style="western"><surname>Tan</surname><given-names>Sheryn</given-names></name><xref ref-type="aff" rid="aff3">3</xref></contrib><contrib contrib-type="author"><name name-style="western"><surname>Ng</surname><given-names>Jeng Swen</given-names></name><xref ref-type="aff" rid="aff3">3</xref></contrib><contrib contrib-type="author"><name name-style="western"><surname>Sateakeerthy</surname><given-names>Shrirajh</given-names></name><xref ref-type="aff" rid="aff5">5</xref></contrib><contrib contrib-type="author"><name name-style="western"><surname>Booth</surname><given-names>Andrew</given-names></name><xref ref-type="aff" rid="aff6">6</xref></contrib><contrib contrib-type="author"><name name-style="western"><surname>Beath</surname><given-names>Alexander</given-names></name><xref ref-type="aff" rid="aff1">1</xref></contrib><contrib contrib-type="author"><name name-style="western"><surname>Kefalianos</surname><given-names>John</given-names></name><xref ref-type="aff" rid="aff1">1</xref></contrib><contrib contrib-type="author"><name name-style="western"><surname>Jacob</surname><given-names>Mathew Ollapallil</given-names></name><xref ref-type="aff" rid="aff1">1</xref><xref ref-type="aff" rid="aff2">2</xref></contrib><contrib contrib-type="author"><name name-style="western"><surname>Ahmed</surname><given-names>Sadeya</given-names></name><xref ref-type="aff" rid="aff3">3</xref></contrib><contrib contrib-type="author"><name name-style="western"><surname>Chan</surname><given-names>WengOnn</given-names></name><xref ref-type="aff" rid="aff3">3</xref></contrib><contrib contrib-type="author"><name name-style="western"><surname>Kovoor</surname><given-names>Pramesh</given-names></name><xref ref-type="aff" rid="aff7">7</xref></contrib><contrib contrib-type="author"><name name-style="western"><surname>Gluck</surname><given-names>Samuel</given-names></name><xref ref-type="aff" rid="aff3">3</xref></contrib><contrib contrib-type="author"><name name-style="western"><surname>Gilbert</surname><given-names>Toby</given-names></name><xref ref-type="aff" rid="aff8">8</xref></contrib><contrib contrib-type="author"><name name-style="western"><surname>Malycha</surname><given-names>James</given-names></name><xref ref-type="aff" rid="aff3">3</xref></contrib><contrib contrib-type="author"><name name-style="western"><surname>Reddi</surname><given-names>Benjamin A</given-names></name><xref ref-type="aff" rid="aff3">3</xref></contrib><contrib contrib-type="author"><name name-style="western"><surname>Padbury</surname><given-names>Robert T</given-names></name><xref ref-type="aff" rid="aff9">9</xref></contrib><contrib contrib-type="author"><name name-style="western"><surname>Trochsler</surname><given-names>Markus I</given-names></name><xref ref-type="aff" rid="aff8">8</xref></contrib><contrib contrib-type="author"><name name-style="western"><surname>Maddern</surname><given-names>Guy J</given-names></name><xref ref-type="aff" rid="aff3">3</xref></contrib><contrib contrib-type="author"><name name-style="western"><surname>Chew</surname><given-names>Derek P</given-names></name><xref ref-type="aff" rid="aff9">9</xref></contrib><contrib contrib-type="author"><name name-style="western"><surname>Zannettino</surname><given-names>Andrew C</given-names></name><xref ref-type="aff" rid="aff3">3</xref></contrib><contrib contrib-type="author"><name name-style="western"><surname>Liew</surname><given-names>Danny</given-names></name><xref ref-type="aff" rid="aff3">3</xref></contrib><contrib contrib-type="author"><name name-style="western"><surname>Beltrame</surname><given-names>John F</given-names></name><xref ref-type="aff" rid="aff3">3</xref></contrib><contrib contrib-type="author"><name name-style="western"><surname>O&#x2019;Callaghan</surname><given-names>Patrick G</given-names></name><xref ref-type="aff" rid="aff3">3</xref></contrib><contrib contrib-type="author"><name name-style="western"><surname>Papendick</surname><given-names>Cynthia</given-names></name><xref ref-type="aff" rid="aff10">10</xref></contrib><contrib contrib-type="author"><name name-style="western"><surname>Bacchi</surname><given-names>Stephen</given-names></name><xref ref-type="aff" rid="aff3">3</xref></contrib></contrib-group><aff id="aff1"><institution>Grampians Health</institution><addr-line>1 Drummond Street N</addr-line><addr-line>Ballarat Central</addr-line><country>Australia</country></aff><aff id="aff2"><institution>The University of Melbourne</institution><addr-line>Grattan Street</addr-line><addr-line>Parkville</addr-line><country>Australia</country></aff><aff id="aff3"><institution>The University of Adelaide</institution><addr-line>Adelaide</addr-line><country>Australia</country></aff><aff id="aff4"><institution>New South Wales Health</institution><addr-line>Sydney</addr-line><country>Australia</country></aff><aff id="aff5"><institution>Central Adelaide, Government of South Australia</institution><addr-line>Adelaide</addr-line><country>Australia</country></aff><aff id="aff6"><institution>South Australia Health</institution><addr-line>Adelaide</addr-line><country>Australia</country></aff><aff id="aff7"><institution>Westmead Hospital</institution><addr-line>Sydney</addr-line><country>Australia</country></aff><aff id="aff8"><institution>The Queen Elizabeth Hospital</institution><addr-line>Adelaide</addr-line><country>Australia</country></aff><aff id="aff9"><institution>Flinders University</institution><addr-line>Adelaide</addr-line><country>Australia</country></aff><aff id="aff10"><institution>Royal Adelaide Hospital</institution><addr-line>Adelaide</addr-line><country>Australia</country></aff><contrib-group><contrib contrib-type="editor"><name name-style="western"><surname>Emam</surname><given-names>Khaled El</given-names></name></contrib></contrib-group><author-notes><corresp>Correspondence to Joshua George Kovoor, MBBS, Grampians Health, 1 Drummond Street N, Ballarat Central, 3350, Australia, 61 53204000; <email>joshuakovoor@gmail.com</email></corresp></author-notes><pub-date pub-type="collection"><year>2025</year></pub-date><pub-date pub-type="epub"><day>19</day><month>12</month><year>2025</year></pub-date><volume>4</volume><elocation-id>e67321</elocation-id><history><date date-type="received"><day>10</day><month>10</month><year>2024</year></date><date date-type="rev-recd"><day>07</day><month>05</month><year>2025</year></date><date date-type="accepted"><day>22</day><month>05</month><year>2025</year></date></history><copyright-statement>&#x00A9; Joshua George Kovoor, Gavin John Carmichael, Brandon Stretton, Aashray K Gupta, Oliver S Kleinig, Mana Ittimani, Jack Fabian, Sheryn Tan, Jeng Sweng Ng, Shrirajh Sateakeerthy, Andrew Booth, Alexander Beath, John Kefalianos, Mathew Ollapallil Jacob, Sadeya Ahmed, Weng Onn Chan, Pramesh Kovoor, Samuel Gluck, Toby Gilbert, James Malycha, Benjamin A Reddi, Robert T Padbury, Markus I Trochsler, Guy J Maddern, Derek P Chew, Andrew C Zannettino, Danny Liew, John F Beltrame, Patrick G O&#x2019;Callaghan, Cynthia Papendick, Stephen Bacchi. Originally published in JMIR AI (<ext-link ext-link-type="uri" xlink:href="https://ai.jmir.org">https://ai.jmir.org</ext-link>), 19.12.2025. </copyright-statement><copyright-year>2025</copyright-year><license license-type="open-access" xlink:href="https://creativecommons.org/licenses/by/4.0/"><p>This is an open-access article distributed under the terms of the Creative Commons Attribution License (<ext-link ext-link-type="uri" xlink:href="https://creativecommons.org/licenses/by/4.0/">https://creativecommons.org/licenses/by/4.0/</ext-link>), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work, first published in JMIR AI, is properly cited. The complete bibliographic information, a link to the original publication on <ext-link ext-link-type="uri" xlink:href="https://www.ai.jmir.org/">https://www.ai.jmir.org/</ext-link>, as well as this copyright and license information must be included.</p></license><self-uri xlink:type="simple" xlink:href="https://ai.jmir.org/2025/1/e67321"/><related-article related-article-type="commentary article" id="v3" ext-link-type="doi" xlink:href="10.2196/52190" xlink:title="Comment on" vol="3" xlink:type="simple">https://ai.jmir.org/2024/1/e52190</related-article><related-article related-article-type="commentary" ext-link-type="doi" xlink:href="10.2196/73342" xlink:title="Comment in" xlink:type="simple">https://ai.jmir.org/2025/1/e73342/</related-article><kwd-group><kwd>AI</kwd><kwd>artificial intelligence</kwd><kwd>prediction</kwd><kwd>TF-IDF</kwd><kwd>health informatics</kwd><kwd>patient care</kwd><kwd>hospital resource management</kwd><kwd>resource management</kwd><kwd>language model</kwd><kwd>machine learning</kwd><kwd>hospitalization</kwd><kwd>deep learning</kwd><kwd>logistic regression</kwd><kwd>retrospective analysis</kwd><kwd>large language model</kwd><kwd>emergency department</kwd></kwd-group></article-meta></front><body><p>We were pleased to read Patel et al&#x2019;s article, &#x201C;Traditional Machine Learning, Deep Learning, and BERT (Large Language Model) Approaches for Predicting Hospitalizations from Nurse Triage Notes&#x201D; [<xref ref-type="bibr" rid="ref1">1</xref>] published in <italic>JMIR AI</italic>. The study compared machine learning (ML) models, including the Bidirectional Encoder Representations from Transformers (BERT)&#x2013;based model &#x201C;Bio-Clinical-BERT&#x201D; and term frequency&#x2013;inverse document frequency (TF-IDF), to predict hospitalizations based on nurse triage notes. We commend the authors for their valuable contribution to the field of ML predictive analytics. Their findings align with our recent work aimed at enhancing patient flow through emergency departments (ED) using ML models. We wish to highlight our study to further contribute to this growing body of research.</p><p>We aimed to evaluate the performance of various ML models in predicting three key outcomes in ED patients&#x2019; journeys: prolonged ED length of stay (LOS &#x2265;8 h), chest x-ray (CXR) utilization, and inpatient admissions. We analyzed data from 50,000 ED visits at two major public metropolitan hospitals in South Australia and tested XGBoost (extreme gradient boosting), random forest, and logistic regression models. Our primary objective was to assess model accuracy in predicting the outcomes to support clinical decision-making and enhance operational efficiency.</p><p>The patient cohort had a mean age of 52.5 (SD 22.1) years (25,211/50,000, 50.4% female). Additionally, 78.6% (n=39,300) of patients reported English as their primary language. Median ED LOS was 4 hours 31 minutes (IQR 2 h 50 min to 7 h 8 min). CXRs were ordered for 27.2% (n=13,578) of patients, and 26.7% (n=13,343) were admitted as inpatients.</p><p>Among the models evaluated, XGBoost demonstrated the strongest performance across all predictive tasks, achieving area under the receiver operating characteristic curve (AUROC) values of 0.79 for predicting prolonged ED LOS, 0.88 for CXR utilization, and 0.85 for inpatient admissions. The random forest model also performed well, with AUROC scores of 0.78 for prolonged LOS, 0.87 for CXR prediction, and 0.84 for inpatient admissions. Although the logistic regression model was less accurate overall, it still provided AUROC values of 0.70, 0.79, and 0.74 for the same outcomes, respectively. These findings suggest that ML models offer reliable predictive insights, particularly for frequently ordered investigations like CXR, and hold promise for enhancing clinical workflows.</p><p>Key predictors for prolonged ED LOS included terms reflecting the severity of presentation and involvement of emergency services. Notably, the presence of terms such as &#x201C;SAAS&#x201D; (South Australian Ambulance Service), &#x201C;SAPOL&#x201D; (South Australian Police), and &#x201C;ITO&#x201D; (Inpatient Treatment Orders) were strongly associated with extended ED stays.</p><p>Our results closely resemble those of Patel et al [<xref ref-type="bibr" rid="ref1">1</xref>], especially regarding the effective use of traditional and advanced ML techniques as clinical predictors in the ED. Both studies demonstrate the potential benefits of integrating ML into ED workflows. Our research contributes further insights by acknowledging the impact of systemic factors (eg, inpatient bed occupancy on LOS predictions), integration of which could improve the predictive accuracy of ML models and further boost their clinical utility.</p><p>Both studies highlight the need for ongoing research into ML application in health care. Future studies should explore the role of systemic factors and real-time data integration to further enhance the clinical utility of ML models in ED settings, ultimately improving patient outcomes and operational efficiency.</p></body><back><ack><p>This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.</p></ack><fn-group><fn fn-type="conflict"><p>None declared.</p></fn></fn-group><glossary><title>Abbreviations</title><def-list><def-item><term id="abb1">AUROC</term><def><p>area under the receiver operating characteristic curve</p></def></def-item><def-item><term id="abb2">BERT</term><def><p>Bidirectional Encoder Representations from Transformers</p></def></def-item><def-item><term id="abb3">CXR</term><def><p>chest x-ray</p></def></def-item><def-item><term id="abb4">ED</term><def><p>emergency department</p></def></def-item><def-item><term id="abb5">ITO</term><def><p>Inpatient Treatment Orders</p></def></def-item><def-item><term id="abb6">LOS</term><def><p>length of stay</p></def></def-item><def-item><term id="abb7">ML</term><def><p>machine learning</p></def></def-item><def-item><term id="abb8">SAAS</term><def><p>South Australian Ambulance Service</p></def></def-item><def-item><term id="abb9">SAPOL</term><def><p>South Australian Police</p></def></def-item><def-item><term id="abb10">TF-IDF</term><def><p>term frequency&#x2013;inverse document frequency</p></def></def-item><def-item><term id="abb11">XGBoost</term><def><p>extreme gradient boosting</p></def></def-item></def-list></glossary><ref-list><title>References</title><ref id="ref1"><label>1</label><nlm-citation citation-type="journal"><person-group person-group-type="author"><name name-style="western"><surname>Patel</surname><given-names>D</given-names> </name><name name-style="western"><surname>Timsina</surname><given-names>P</given-names> </name><name name-style="western"><surname>Gorenstein</surname><given-names>L</given-names> </name><etal/></person-group><article-title>Traditional machine learning, deep learning, and BERT (large language model) approaches for predicting hospitalizations from nurse triage notes: comparative evaluation of resource management</article-title><source>JMIR AI</source><year>2024</year><month>08</month><day>27</day><volume>3</volume><fpage>e52190</fpage><pub-id pub-id-type="doi">10.2196/52190</pub-id><pub-id pub-id-type="medline">39190905</pub-id></nlm-citation></ref></ref-list></back></article>