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Association between long boarding time in the emergency department and hospital mortality: a single-center propensity score-based analysis

Internal and Emergency Medicine volume 15, pages 479–489 (2020)Cite this article

Abstract

Once diagnostic work-up and first therapy are completed in patients visiting the emergency department (ED), boarding them within the ED until an in-hospital bed became available is a common practice in busy hospitals. Whether this practice may harm the patients remains a debate. We sought to determine whether an ED boarding time longer than 4 h places the patients at increased risk of in-hospital death. This retrospective, propensity score-matched analysis and propensity score-based inverse probability weighting analysis was conducted in an adult ED in a single, academic, 1136-bed hospital in France. All patients hospitalized via the adult ED from January 1, 2013 to March 31, 2018 were included. Hospital mortality (primary outcome) and hospital length of stay (LOS) were assessed in (1) a matched cohort (1:1 matching of ED visits with or without ED boarding time longer than 4 h but similar propensity score to experience an ED boarding time longer than 4 h); and (2) the whole study cohort. Sensitivity analysis to unmeasured confounding and analyses in pre-specified cohorts of patients were conducted. Among 68,632 included ED visits, 17,271 (25.2%) had an ED boarding time longer than 4 h. Conditional logistic regression performed on a 10,581 pair-matched cohort, and generalized estimating equations with adjustment on confounders and stabilized propensity score-based inverse probability weighting applied on the whole cohort showed a significantly increased risk of hospital death in patients experiencing an ED boarding time longer than 4 h: odds ratio (OR) of 1.13 (95% confidence interval [95% CI] 1.05–1.22), P = 0.001; and OR of 1.12 (95% CI 1.03–1.22), P = 0.007, respectively. Sensitivity analyses showed that these findings might be robust to unmeasured confounding. Hospital LOS was significantly longer in patients exposed to ED boarding time longer than 4 h: median difference 2 days (95% CI 1–2) (P < 0.001) in matched analysis and mean difference 1.15 days (95% CI 1.02–1.28) (P < 0.001) in multivariable unmatched analysis. In this single-center propensity score-based cohort analysis, patients experiencing an ED boarding time longer than 4 h before being transferred to an in-patient bed were at increased risk of hospital death.

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Funding

This study was funded only by the Centre hospitalier régional d’Orléans. The funders had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.

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Affiliations

  1. Service D’Accueil Des Urgences Adultes, Centre Hospitalier Régional D’Orléans, Orléans, France

    Thierry Boulain, Anne Malet & Olivier Maitre

  2. Service de Médecine Intensive Réanimation, Centre Hospitalier Régional D’Orléans, Orléans, France

    Thierry Boulain

Authors
  1. Thierry Boulain
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  2. Anne Malet
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  3. Olivier Maitre
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Contributions

TB had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis. Concept and design: TB, AM, OM. Acquisition, analysis, or interpretation of data: TB, AM, OM. Drafting of the manuscript: TB. Critical revision of the manuscript for important intellectual content: TB, AM, OM. Statistical analysis: TB. Obtained funding: TB. Administrative, technical, or material support: TB, AM, OM. Supervision: TB.

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Correspondence to Thierry Boulain.

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The authors declare that they have no financial or non-financial competing interests relative to this submission.

Ethical approval

The Ethical Committee of the French Society of Intensive Care approved the study protocol (#CE SRLF 18-31).

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For this retrospective study that complied with French law requirements related to personal data protection, informed consent was not required.

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Boulain, T., Malet, A. & Maitre, O. Association between long boarding time in the emergency department and hospital mortality: a single-center propensity score-based analysis. Intern Emerg Med 15, 479–489 (2020). https://doi.org/10.1007/s11739-019-02231-z

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  • DOI: https://doi.org/10.1007/s11739-019-02231-z

Keywords

  • Emergency service
  • Hospital
  • Crowding
  • Hospital mortality
  • Propensity score
  • Data interpretation
  • Statistical