Cited by 326Machine Learning in HealthcareEmergency and Acute Care StudiesArtificial Intelligence in Healthcare

Predicting hospital admission at emergency department triage using machine learning

Open access
Hong, Woo Suk, Haimovich, Adrian Daniel, Taylor, R. Andrew·2018·PLOS ONE

Abstract

OBJECTIVE: To predict hospital admission at the time of ED triage using patient history in addition to information collected at triage. METHODS: This retrospective study included all adult ED visits between March 2014 and July 2017 from one academic and two community emergency rooms that resulted in either admission or discharge. A total of 972 variables were extracted per patient visit. Samples were randomly partitioned into training (80%), validation (10%), and test (10%) sets. We trained a series of nine binary classifiers using logistic regression (LR), gradient boosting (XGBoost), and deep neural networks (DNN) on three dataset types: one using only triage information, one using only patient history, and one using the full set of variables. Next, we tested the potential benefit of additional training samples by training models on increasing fractions of our data. Lastly, variables of importance were identified using information gain as a metric to create a low-dimensional model. RESULTS: A total of 560,486 patient visits were included in the study, with an overall admission risk of 29.7%. Models trained on triage information yielded a test AUC of 0.87 for LR (95% CI 0.86-0.87), 0.87 for XGBoost (95% CI 0.87-0.88) and 0.87 for DNN (95% CI 0.87-0.88). Models trained on patient history yielded an AUC of 0.86 for LR (95% CI 0.86-0.87), 0.87 for XGBoost (95% CI 0.87-0.87) and 0.87 for DNN (95% CI 0.87-0.88). Models trained on the full set of variables yielded an AUC of 0.91 for LR (95% CI 0.91-0.91), 0.92 for XGBoost (95% CI 0.92-0.93) and 0.92 for DNN (95% CI 0.92-0.92). All algorithms reached maximum performance at 50% of the training set or less. A low-dimensional XGBoost model built on ESI level, outpatient medication counts, demographics, and hospital usage statistics yielded an AUC of 0.91 (95% CI 0.91-0.91). CONCLUSION: Machine learning can robustly predict hospital admission using triage information and patient history. The addition of historical information improves predictive performance significantly compared to using triage information alone, highlighting the need to incorporate these variables into prediction models.

AI snapshot

Written from the paper’s full text.

TL;DR

Machine learning models using electronic health record data predicted hospital admission at ED triage, with full-variable models reaching test AUCs of 0.91–0.92. Adding patient history significantly improved performance over triage information alone.

Key findings

  • Among 560,486 adult ED visits with an overall admission risk of 29.7%, full-variable models achieved test AUC 0.91 for logistic regression, 0.92 for XGBoost, and 0.92 for deep neural networks; triage-only and history-only models achieved AUCs around 0.86–0.87.
  • A low-dimensional XGBoost model using ESI level, outpatient medication counts, demographics, and hospital usage statistics yielded an AUC of 0.91 (95% CI 0.91–0.91).
  • All algorithms reached maximum performance at 50% of the training set or less; logistic regression reached it at 10%, while XGBoost and DNN reached it at 50%.
  • XGBoost and DNN outperformed logistic regression on the full dataset, with no significant difference between XGBoost and DNN across the three dataset types.

Methods

  • Retrospective study of all adult ED visits between March 2014 and July 2017 from one academic and two community EDs that ended in admission or discharge; 972 variables were extracted per visit, and 560,486 visits were randomly partitioned into training (80%), validation (10%), and test (10%) sets.
  • Nine binary classifiers were trained using logistic regression, XGBoost, and deep neural networks on three dataset types: triage information only, patient history only, and the full variable set; hyperparameters were optimized by average validation AUC across five validation sets, and test AUCs were calculated with DeLong 95% CIs.
  • Additional analyses trained full-variable models on increasing fractions of the training set (1%, 10%, 30%, 50%, 80%, 100%) and used information gain from 100 XGBoost iterations to identify important variables and build a low-dimensional model.

Limitations

  • The paper states that patient history was restricted to previous ED visits, and expanding to outpatient or inpatient data may improve performance but could present EHR integration and differing-standards difficulties.
  • The paper states that data came from one hospital system with multiple EDs and a large catchment area, and extending the approach to dense urban areas with multiple independent EDs may be difficult because patients may not consistently present to the same system.
  • The paper states that the outcome label was the ED provider’s prior disposition decision, so appropriateness of individual clinical decisions could not be assessed, and it does not address implementation or efficacy barriers in clinical practice; evident from the text, the study is retrospective, adult-only, excludes non-admission/discharge dispositions, and uses a held-out test set from the same health system rather than external validation.

Model-written summary. Check it against the paper before relying on it.

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Registry

Crossref · 10.1371/journal.pone.0201016

Cites

57 of 57 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Claims the paper makes

0 of 46 cited sources checked · 0 supported · 0 flagged

  • Findingown data

    Models trained on triage information yielded a test AUC of 0.87 for DNN (95% CI 0.87-0.88).

    “Models trained on triage information yielded a test AUC of 0.87 for LR (95% CI 0.86–0.87), 0.87 for XGBoost (95% CI 0.87–0.88) and 0.87 for DNN (95% CI 0.87–0.88).”
    Quote in the paperSubstantial claim
  • Findingown data

    The addition of patient history improves predictive performance significantly compared to using triage information alone.

    “the addition of patient history improves predictive performance significantly compared to using triage information alone”
    Quote in the paperSubstantial claim
  • Findingown data

    Prior hospital usage statistics such as the number of admissions within the past year and the disposition of the previous ED visit had high information gain in the full XGBoost model.

    “as did prior hospital usage statistics such as the number of admissions within the past year and the disposition of the previous ED visit.”
    Quote in the paperNot a substantial claim
  • Findingown data

    For LR, the 95% CI of the AUC of the model trained on 10% of the training set contained the AUC of the model trained on the entire training set.

    “For LR, the 95% CI of the AUC of the model trained on 10% of the training set contained the AUC of the model trained on the entire training set.”
    Quote in the paperSubstantial claim
  • Findingown data

    Models trained on patient history yielded an AUC of 0.86 for LR (95% CI 0.86-0.87).

    “Models trained on patient history yielded an AUC of 0.86 for LR (95% CI 0.86–0.87), 0.87 for XGBoost (95% CI 0.87–0.87) and 0.87 for DNN (95% CI 0.87–0.88).”
    Quote in the paperNot a substantial claim
  • May combine two claims. 5
  • The quote only partly states this claim. 1
  • Classified as probably not a substantial claim. 10
  • May combine two claims. The quote only partly states this claim.

    Findingown data

    All three algorithms reach maximum performance at 50% of the training set or less (the AUC plateaus well below the full training set).

    “All three algorithms reach maximum performance at 50% of the training set or less.”
    • Also stated in: § Discussion · boosted
      “we train our models on increasing fractions of the training set and show that the AUC plateaus well below the full training set.”
    Quote in the paperSubstantial claim
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    EDs represent the largest source of hospital admissions.

    “While most emergency department (ED) visits end in discharge, EDs represent the largest source of hospital admissions [1].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [1] Moore B, Stocks C, Owens P. Trends in Emergency Department Visits, 2006–2014. HCUP Statistical Brief #227 [Internet]. Agency for Healthcare Research and Quality; 2017 Sep. Available: <ext-link xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="uri" xlink:href="https://www.hcup-us.ahrq.gov/reports/statbriefs/sb227-Emergency-Department-Visit-Trends.pdf" xlink:type="simple">https://www.hcup-us.ahrq.gov/reports/statbriefs/sb227-Emergency-Department-Visit-Trends.pdf</ext-link>

      Not checked in the free run.

  • Classified as probably not a substantial claim.

    Premisecitation

    ED crowding is correlated with poorer patient outcomes.

    “It is increasingly understood that ED crowding is correlated with poorer patient outcomes [10].”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [10] SL Bernstein, 2009, The Effect of Emergency Department Crowding on Clinically Oriented Outcomes, Acad Emerg Med source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Interpretationcitation

    The importance of medication counts in the model may either reflect a proxy feature for medical complexity or indicate that polypharmacy itself is a risk factor.

    “the importance of medication counts in the model may either reflect a proxy feature for medical complexity or indicate that polypharmacy itself is a risk factor [42,43].”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [42] CM Hohl, 2001, Polypharmacy, adverse drug-related events, and potential adverse drug interactions in elderly patients presenting to an emergency department, Ann Emerg Med source

      Not checked in the free run.

    • cites [43] A Banerjee, 2011, The prevalence of polypharmacy in elderly attenders to an emergency department—a problem with a need for an effective solution, Int J Emerg Med source

      Not checked in the free run.

  • Classified as probably not a substantial claim. May combine two claims.

    Premisecitation

    A progressive modeling approach that uses information available at later time-points has been able to achieve high predictive power and indicates the utility of these features.

    “Notably, a progressive modeling approach that uses information available at later time-points, such as lab tests ordered, medications given, and diagnoses entered by the ED provider during the patient’s current visit, has been able to achieve high predictive power and indicates the utility of these features [20,21].”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [20] Y Barak-Corren, 2017, Progressive prediction of hospitalisation in the emergency department: uncovering hidden patterns to improve patient flow, Emerg Med J source

      Not checked in the free run.

    • cites [21] Y Barak-Corren, 2017, Early Prediction Model of Patient Hospitalization From the Pediatric Emergency Department, Pediatrics source

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  • Classified as probably not a substantial claim.

    Study design and conductown data

    Samples were randomly partitioned into training (80%), validation (10%), and test (10%) sets.

    “Samples were randomly partitioned into training (80%), validation (10%), and test (10%) sets.”
    • Also stated in: § Model fitting and evaluation · plain
      “A randomly chosen test set of 56,000 (10%) samples was held out, then the remaining 504,486 (90%) samples split randomly five times to create five independent validation sets of 56,000 (10%) and training sets of 448,486 (80%).”
    Quote in the paperSubstantial claim
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Variables correlated with age and markers of socioeconomic status such as insurance type have been previously linked to hospital admission.

    “that have been previously linked to hospital admission [46–48].”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites [46] AW Selassie, 2003, The Influence of Insurance, Race, and Gender on Emergency Department Disposition, Acad Emerg Med source

      Not checked in the free run.

    • cites [47] Jiang HJ, Russo CA, Barrett ML. Nationwide Frequency and Costs of Potentially Preventable Hospitalizations, 2006. HCUP Statistical Brief #72 [Internet]. Agency for Healthcare Research and Quality; 2009 Apr. Available: <ext-link xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="uri" xlink:href="http://www.hcup-us.ahrq.gov/reports/statbriefs/sb72.pdf" xlink:type="simple">http://www.hcup-us.ahrq.gov/reports/statbriefs/sb72.pdf</ext-link>

      Not checked in the free run.

    • cites [48] S Kangovi, 2013, Understanding Why Patients Of Low Socioeconomic Status Prefer Hospitals Over Ambulatory Care, Health Aff (Millwood) source

      Not checked in the free run.

  • Classified as probably not a substantial claim.

    Premisecitation

    Using all elements of the electronic health record can robustly predict in-patient outcomes.

    “As a recent work showed that using all elements of the electronic health record can robustly predict in-patient outcomes [26]”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [26] A Rajkomar, 2018, Scalable and accurate deep learning for electronic health records, Npj Digit Med source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Logistic regression and Naive Bayes are commonly used, with few studies using more complex algorithms like random-forests, artificial neural networks, and support vector machines.

    “Logistic regression and Naive Bayes are commonly used [9,11,16,18–22], with few studies using more complex algorithms like random-forests, artificial neural networks, and support vector machines [12,15,17].”
    Quote in the paperSubstantial claim0 of 10 sources checked
    • cites [9] Y Sun, 2011, Predicting hospital admissions at emergency department triage using routine administrative data, Acad Emerg Med source

      Not checked in the free run.

    • cites [11] JS Peck, 2012, Predicting emergency department inpatient admissions to improve same-day patient flow, Acad Emerg Med source

      Not checked in the free run.

    • cites [16] J Leegon, 2005, Predicting Hospital Admission for Emergency Department Patients using a Bayesian Network, AMIA Annu Symp Proc

      Not checked in the free run.

    • cites [18] DW Savage, 2017, P112: Predicting patient admission from the emergency department using triage administrative data, Can J Emerg Med source

      Not checked in the free run.

    • cites [19] JA Lucke, 2017, Early prediction of hospital admission for emergency department patients: a comparison between patients younger or older than 70 years, Emerg Med J

      Not checked in the free run.

    • cites [20] Y Barak-Corren, 2017, Progressive prediction of hospitalisation in the emergency department: uncovering hidden patterns to improve patient flow, Emerg Med J source

      Not checked in the free run.

    • cites [21] Y Barak-Corren, 2017, Early Prediction Model of Patient Hospitalization From the Pediatric Emergency Department, Pediatrics source

      Not checked in the free run.

    • cites [22] MM Dinh, 2016, The Sydney Triage to Admission Risk Tool (START) to predict Emergency Department Disposition: A derivation and internal validation study using retrospective state-wide data from New South Wales, Australia, BMC Emerg Med source

      Not checked in the free run.

    • cites [12] S Levin, 2017, Machine-Learning-Based Electronic Triage More Accurately Differentiates Patients With Respect to Clinical Outcomes Compared With the Emergency Severity Index, Ann Emerg Med

      Not checked in the free run.

    • cites [15] J Leegon, 2006, Predicting Hospital Admission in a Pediatric Emergency Department using an Artificial Neural Network, AMIA Annu Symp Proc

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Prior models that incorporate past medical history utilize simplified chronic disease categories such as heart disease or diabetes while leaving out rich historical information accessible from the EHR such as outpatient medications and historical labs and vitals.

    “Prior models that incorporate past medical history utilize simplified chronic disease categories such as heart disease or diabetes [9,12] while leaving out rich historical information accessible from the electronic health record (EHR) such as outpatient medications and historical labs and vitals”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [9] Y Sun, 2011, Predicting hospital admissions at emergency department triage using routine administrative data, Acad Emerg Med source

      Not checked in the free run.

    • cites [12] S Levin, 2017, Machine-Learning-Based Electronic Triage More Accurately Differentiates Patients With Respect to Clinical Outcomes Compared With the Emergency Severity Index, Ann Emerg Med

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S2 (checkable).

    Premisecitation

    Notification of administrators and inpatient teams regarding potential admissions may help alleviate ED crowding.

    “Notification of administrators and inpatient teams regarding potential admissions may help alleviate this problem [11].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [11] JS Peck, 2012, Predicting emergency department inpatient admissions to improve same-day patient flow, Acad Emerg Med source

      Not checked in the free run.

  • Classified as probably not a substantial claim.

    Premisecitation

    Some prior models predicting hospital admission at ED triage include additional features such as hospital usage statistics and past medical history.

    “while some models include additional features such as hospital usage statistics and past medical history [9,12,20,21].”
    Quote in the paperSubstantial claim0 of 4 sources checked
    • cites [9] Y Sun, 2011, Predicting hospital admissions at emergency department triage using routine administrative data, Acad Emerg Med source

      Not checked in the free run.

    • cites [12] S Levin, 2017, Machine-Learning-Based Electronic Triage More Accurately Differentiates Patients With Respect to Clinical Outcomes Compared With the Emergency Severity Index, Ann Emerg Med

      Not checked in the free run.

    • cites [20] Y Barak-Corren, 2017, Progressive prediction of hospitalisation in the emergency department: uncovering hidden patterns to improve patient flow, Emerg Med J source

      Not checked in the free run.

    • cites [21] Y Barak-Corren, 2017, Early Prediction Model of Patient Hospitalization From the Pediatric Emergency Department, Pediatrics source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductcitation

    This study does not address the implementation and efficacy barriers present in clinical practice.

    “Lastly, this study does not address the implementation and efficacy barriers present in clinical practice [53].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [53] SM Schenkel, 2018, Triage, Machine Learning, Algorithms, and Becoming the Borg, Ann Emerg Med

      Not checked in the free run.

13 of 13
  • The paper relies on this without support.

    Gradient boosting and deep neural networks have not been applied to the task of predicting admission at ED triage to date.

    “While gradient boosting and deep neural networks have been shown to be powerful tools for predictive modeling, neither has been applied to the task of predicting admission at ED triage to date.”
  • The paper relies on this without support.

    The three EDs studied are representative of EDs generally, so the models' performance generalizes to other settings.

    “Machine learning can robustly predict hospital admission using triage information and patient history.”
  • The paper relies on this without support.

    The historical information available in the EHR at the time of triage is sufficiently complete and accurate to predict admission.

    “For each patient visit, we collected a total of 972 variables, divided into major categories shown in Table 1.”
  • The paper relies on this without support.

    The ED provider's prior decision is a valid ground truth for hospital admission.

    “Throughout this study, we predict patient disposition by using the ED provider's prior decision as our true label.”
  • The paper relies on this without support.

    The variables used in the models are available at the time of emergency department triage.

    “Our study shows that machine learning can robustly predict hospital admission at emergency department (ED) triage”
5 of 5

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Each contradiction between two passages listed here was confirmed by an independent check.

  • Conflicting descriptions of how model cutoffs were chosen

    Minor

    The methods say Youden's index determined the cutoff for each model. Table 3 instead says every model's cutoff was set to a fixed specificity of 0.85, chosen using Youden's index only on the full XGBoost model.

1 of 1

Cites

Flagged first, then by citations

1 of the 58 references couldn’t be matched to a known paper.

Research works printed but not linked: 1

  1. M Kuhn, 2013, Chapter 3. Data Pre-processing. Applied Predictive Modeling, Springer Science & Business Media, 27

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Authors
Hong, W. S., Haimovich, A. D., & Taylor, R. A.
Affiliations
Yale University (US)
Corresponding author
Taylor, R. Andrew
Venue
PLOS ONE
Published
2018-07-20
Volume
13
Issue
7
Pages
e0201016
ISSN
1932-6203 (ISSN-L)
OpenAlex
W2884597820
Cited by
326
References
58
Citations by year
2026: 51 · 2025: 55 · 2024: 47 · 2023: 39 · 2022: 46 · 2021: 39 · 2020: 30 · 2019: 18 · 2018: 1
FWCI
12.22
Type
journal article
Language
en
Open access
Locations
  • PLoS ONE (publishedVersion, cc-by)
  • Europe PMC (PubMed Central) (publishedVersion, cc-by)
  • PubMed Central (publishedVersion, cc-by)
  • PubMed (publishedVersion)
  • RePEc: Research Papers in Economics (submittedVersion)
  • DOAJ (DOAJ: Directory of Open Access Journals) (submittedVersion)
  • Figshare (submittedVersion, cc-by)
Funders
  • National Institutes of Health (1F30CA196191, T32GM007205)
  • Yale School of Medicine
Topics
  • Physical Sciences › Computer Science › Artificial Intelligence › Machine Learning in Healthcare
  • Health Sciences › Medicine › Emergency Medicine › Emergency and Acute Care Studies
  • Health Sciences › Health Professions › Health Information Management › Artificial Intelligence in Healthcare
Keywords
emergency department triage, hospital admission prediction, medical history, Emergency Severity Index, hospital utilization, XGBoost, deep neural network, logistic regression, feature importance, information gain, low-dimensional models, training data size, model generalization, clinical decision support
MeSH terms
Machine Learning, Adult, Emergency Service, Hospital, Female, Humans, Male, Middle Aged, Patient Admission, Patient Discharge, Triage, Models, Statistical

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